PhD (Entomology) Associate Professor Phone: 17797939290 Address: Department of Plant Protection, Agricultural College, Shihezi University, SHihezi 832003, Xinjianjg, China
Tamarixia radiata is one of the established biocontrol pests against the major Asian citrus psyll... more Tamarixia radiata is one of the established biocontrol pests against the major Asian citrus psyllid, Diaphorina citri, a vector of Candidatus Liberibacter that is a causal agent of citrus Huanglongbing (HLB) disease. Updated information and regional exploration on biocontrol pests are important elements for effective disease management strategies. In this study, the diversity and parasitism rate of T. radiata populations were evaluated. Due to the importance of the host–parasitoid relationship, the presence of Wolbachia as an endosymbiont was also investigated. The parasitism rate of various T. radiata populations from Ecuador and China ranged between 57.27% and 66.32%, respectively, with a non-significant emergence rate and a statistically similar sex ratio. Sequence analysis of ITS and COI from T. radiata populations was consistent with the morphological hypothesis that the collections represent a single species, whereas phylogeny of the wsp gene confirmed the presence of Wolbachia pipientis as an endosymbiont within T. radiata populations. Based on partial COI sequences, the maximum genetic diversity such as total haplotype diversity (Hd = 0.788), nucleotide, diversity (π = 0.2439), and average nucleotide difference (k = 171.844) was also estimated for different T. radiata populations. Furthermore, neutrality tests based on COI sequences indicated an overall contraction in T. radiata populations, whereas an expansion trend was observed in associated W. pipientis strains. This study clearly demonstrated the presence of genetically diverse T. radiata populations that were able to parasitize D. citri effectively, and these can be further explored as promising biocontrol candidates in integrated pest management strategies to solve citriculture economic loss caused by D. citri.
Bactrocera zonata (Saunders) and Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) are major pe... more Bactrocera zonata (Saunders) and Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) are major pests of fruits especially guava, posing a trade barrier of Pakistani fruits in foreign markets. Mass trapping of this pest by suitable selection of traps is necessary for its management by the male annihilation technique (MAT). Experiments were conducted in three different guava-producing districts of Punjab, i.e., Faisalabad, Sargodha, and Toba Tek Singh. Three locations in each district were selected for the experiment, three acres each. Three types of traps were used: the round trap (RT), the jar trap (JT), and the pet bottle trap (PBT), with six traps per acre. Multiple linear regression equations and correlations were computed on the mean population data for all traps in each year. April, May, and June (standard weeks 13-23) were fruit fly peak activity periods in all districts. Temperature exerted a highly significant and positive impact on fruit fly populations. Humidity was not significant, but showed a positive relationship with per unit population fluctuation. Rainfall was also not significant, but showed a negative relationship with per unit population fluctuation. The maximum impact of temperature was 43.5 and 42.8% in Faisalabad, the maximum impact of relative humidity was 26.2 and 22.2% in Sargodha, Faisalabad, and the maximum impact of rainfall was 26.3 and 15.1% in Sargodha. The PBT trap had significant and positive correlations with per unit population fluctuation in all three districts during 2015 and 2016. Pet bottle traps gave the maximum adult catches at all districts with minimum cost 13.30 $/ha in a year, which is suitable for farmer’s community to be used in a prediction model.
The current study was conducted to assess the impact of powdery mildew (Oidium neolycopersici) on... more The current study was conducted to assess the impact of powdery mildew (Oidium neolycopersici) on plant-non-vector herbivore-parasitoid interactions, e.g. tomato plants, whiteflies (Trialeurodes vaporariorum) and parasitoid (Encarsia formosa). Encarsia females were significantly less attracted to powdery mildew infected tomato plants (PM) than healthy plants (Con.). Thus parasitism rates of whiteflies (WF) were significantly lower on powdery mildew (PM) plants as compared to Con. plants (17.5:41.5%). These differences disappeared when E. formosa females were forced to parasitize whiteflies on either PM or Con. The performance of the parasitoid was not significantly influenced when developing on whiteflies feeding on powdery mildew infected plants. In olfactometer bioassays, either naïve or experienced parasitoids significantly preferred healthy plants colonised by whiteflies as compared to powdery mildew infected plants colonised by whitefly (PMWF) (30.0:10.0% for naïve parasitoids; 41.4:15.2% for experienced parasitoids). In wind tunnel bioassays, volatiles emitting from WFs significantly increased upwind oriented flight and landing in Encarsia targets as compared to any other treatments. Volatiles from Con, PM, PMWF and WF were collected and analyzed by GC and GC-MS, revealing that both qualities and quantities of volatile compounds differed to a large extend. Plants significantly increased volatile emission after being attacked by whiteflies (275.3 mol h−1) or infected by powdery mildew (267.58 mol h−1). However, plants significantly reduced volatile emissions in PMWF co-existing systems (80.58 mol h−1). Our results demonstrate that volatiles released by either herbivore damaged plants, pathogen diseased plants or combinations of these agents, respectively, may influence the foraging behavior of the parasitoids while searching for their hosts, resulting in reduced efficacies of parasitoids. This, in turn, may impact the outcome of biological control systems, especially in greenhouse conditions.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
This study was executed to assess the disruption in nutritional attributes of Capsicum annuum by ... more This study was executed to assess the disruption in nutritional attributes of Capsicum annuum by five different microplastic (MP) types i.e. polyvinylchloride (PVC), polystyrene (PS), high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polyethylene terephthalate (PET). Significant (P 0.05) differences were recorded among traits of C. annuum fruit concerning the type of MPs. PVC was more hazardous than the other MPs and depleted maximum protein content. Likewise, HDPE exerted a 51.62% reduction in carbohydrates compared to the control. Vitamin-A (-32.09%) and vitamin-B6 (-37%) were severely influenced by the PVC in C. annuum fruit. HDPE and PVC both declined the oleic acid contents. PVC caused a 47.6% reduction in linoleic acid while the least damaging was the PET (4.71%) for this attribute. Palmitic acid and stearic acid were however more negatively affected by the HDPE. The PVC and HDPE severely degraded the total flavonoid contents and phenolics. Macro and micronutrients of C. annuum fruit were also negatively influenced by all the five MPs used in this study. HDPE, PVC and LDPE, respectively caused significant repression in Ca, K, Mg and Zn (P 0.05). Overall, HDPE and PVC caused significant damage and decreased nutritional contents. This is, so far, the premier study unraveling the changes in the nutrition of C. annuum fruits due to MPs. Accordingly, further research is highly recommended on the changes caused by MPs in the nutritional value of food crops.
Plants, being sessile in nature, are inept to escape biotic stress that adversely impact their gr... more Plants, being sessile in nature, are inept to escape biotic stress that adversely impact their growth, development, and productivity. Rather, plants employ a variety of processes at the molecular, morphological, physiological as well as biochemical levels to mitigate the negative impacts of such stressors. Plants have a complex defense system against pathogens, pests and diseases, which includes collaborative actions regulated by array of genes and transcription factors. Immunity against pathogenic attack is determined by the plant's ability to avoid early infection and limit the growth of harmful pathogens, whereas resistance to microbial toxins is determined by the capacity of plant tissues to reduce toxin accumulation and its detoxification. This ability can be achieved through modulations in multiple processes. Among these processes, regulation of the antioxidant defense system, generation of reactive oxygen species and production of secondary metabolites is reckoned as an essential component of defense mechanism. Antioxidants such as superoxide dismutase (SOD), peroxidase (POD) and secondary metabolites, specifically phenolics, terpenes, and nitrogen-containing compounds have been widely proven to defend plants against range of biotic stresses. It is essentially needed to improve existing management practices to control pathogens and breed immunity in crops for sustainable agriculture and food security. Particularly to improve resistance to pathogenesis, the breeding of long-term resilience in cereals genotypes is one of the most promising strategies. A better grasp of the molecular processes underlying plant resilience to microbial assault will cast light on plant-pathogen interactions and provide useful information for breeding programs. This review emphasizes the ongoing investigation and significant operation of key molecular, physiological, and biochemical factors for tolerance and resistance in Oryza sativa against microbial infections. Additionally, we have focused on secondary metabolites and antioxidant defense system playing a crucial role in deciding how plants react to pathogen attacks.
Microbial pathogens attack every plant tissue, including leaves, roots, shoots, and flowers durin... more Microbial pathogens attack every plant tissue, including leaves, roots, shoots, and flowers during all growth stages. Thus, they cause several diseases resulting in a plant's failure or loss of the whole crop in severe cases. To combat the pathogens attack, plants produce some biologically active toxic compounds known as saponins. The saponins are secondary metabolic compounds produced in healthy plants with potential anti-pathogenic activity and serve as potential chemical barriers against pathogens. Saponins are classified into two major groups the steroidal and terpenoid saponins. Here, we reported the significance of saponin toxins in the war against insect pests, fungal, and bacterial pathogens. Saponins are present in both cultivated (chilies, spinach, soybean, quinoa, onion, oat, tea, etc.) and wild plant species. As they are natural toxic constituents of plant defense, breeders and plant researchers aiming to boost plant imm unity should focus on transferring these compounds in cash crops.
The recent outbreak of Covid-19 is posing a severe threat to public health globally. Coronaviruse... more The recent outbreak of Covid-19 is posing a severe threat to public health globally. Coronaviruses (CoVs) are the largest known group of positive-sense RNA viruses surviving on an extensive number of natural hosts. CoVs are enveloped and non-segmented viruses with a size between 80 and 120 nm. CoV attachment to the surface receptor and its subsequent entrance into cells is mediated by Spike glycoprotein (S). For enhanced CoV entry and successful pathogenesis of CoV, proteolytic processing and receptor-binding act synergistically for induction of large-scale S conformational changes. The shape, size and orientation of receptor-binding domains in viral attachment proteins are well conserved among viruses of different classes that utilize the same receptor. Therefore, investigations unraveling the distribution of cellular receptors with respect to CoV entry, structural aspects of glycoproteins and related conformational changes are highly significant for understanding virus invasion and infection spread. We present the characteristic features of CoV S-Proteins, their significance for CoVs and related receptor binding activities for pathogenesis and viral survival. We are analyzing the novel role of S-protein of CoVs along with their interactive receptors for improving host immunity and decreasing infection spread. This is hoped that presented information will open new ways in tackling coronavirus, especially for the ongoing epidemic.
International Journal of Tropical Insect Science, 2020
Worldwide, stored products are attacked by a large number of pests resulting in significant econo... more Worldwide, stored products are attacked by a large number of pests resulting in significant economic losses. Among these stored grain pests, khapra beetle, Trogoderma granarium (Everts) (Coleoptera: Dermestidae) is one of the top ranked pests that has ability to survive under diverse climate conditions. The management of this pest is mainly done by using synthetic chemicals which have side effects on consumers, ecosystem and non-target organisms. However, phyto-derivatives were found to be the effective environment friendly alternatives against T. granarium. Therefore, in this review, success of phyto-derivatives against khapra beetle from conventional means to modern research has been critically analyzed, summarized and discussed. In context, the different life stages of the insect starting from egg laying to adult development have been briefly explained. The review focuses upon recent research conducted on the evaluation of dozens of phyto-derivatives. In addition, the article has also highlighted some limitations of plant derived compounds and concludes via hoping that the future formulated pesticides will be safer, economical, least toxic to human and our planet ecosystem.
American bollworm (ABW), Helicoverpa armigera (Hubner), is considered as a major pest of cotton, ... more American bollworm (ABW), Helicoverpa armigera (Hubner), is considered as a major pest of cotton, Gossyp-ium hirsutum, all over the globe. Due to its destructive feeding nature and continuous consumption of the same chemicals, it devolved resistant against many insecticides. Therefore, a combined application of bio-and synthetic-pesticide need to evaluate against this pest. The entomopathogenic viruses like nuclear polyhedrosis virus (NPV), a member of baculoviruses, can be the potential candidates for better control against ABW. The present study was conducted to assess the comparative efficacy of NPV and Spinosad 240SC (with the concentration of 250 mL · ha − l) against ABW in the controlled environment. The ABW was treated with different concentrations of NPV and Spinosad separately and in a combination of NPV with 0.1% Spinosad. The results revealed that highest concentrations showed highest mortality (95%) followed by 95%, 92%, 84%, 82% and 78% mortality at 1 × 10 9 , 1 × 10 8 , 1 × 10 7 , 1 × 10 6 and 1 × 10 5 POBs, respectively. Spinosad when mixed in diet give 100% mortality at 0.8% followed by 50.87%, 42.10%, 29.82%, 26.31% and 22.80% mortality at 0.4%, 0.2%, 0.1%, 0.5% and 0.025% respectively. The results of this study revealed that microbial control of ABW through NPV is an effective tool. The repeated use of synthetic pesticides caused the resurgence of many insect pests, and this study results would provide useful insight to build a framework for future investigations for the management of many major insect pests.
The house fly, Musca domestica L. (Diptera: Muscidae), is a major pest of all aspects of life, li... more The house fly, Musca domestica L. (Diptera: Muscidae), is a major pest of all aspects of life, like the domestic, medical and veterinary and causal agent of several pathogenic diseases. The present study was conducted to evaluate the potential of different insecticide-free baits against house fly by incorporating flower methanol extract of Helianthus annuus (sunflower) and Tegetes erecta (marigold) at 10%, 20% and 30% bait formulation of corn syrup, dried milk and water. However, imidacloprid and thiacloprid (each at 5% concentration) were also included in the study for comparison. Results showed that insecticide baits were superior in causing mortality of adult house fly but dependent upon syrup. Overall, 20% baits of both extracts caused more than half population death of house fly within 48h. On the other hand, the mortality rate by 30% baits (from sunflower and marigold) had a similar impact as observed in case of imidacloprid and thiacloprid baits. Therefore, biological baits could play a more active and safer role in the management of house fly as compared to synthetic insecticides.
A research trial was conducted at Rice Research Institute, Kala Shah Kaku, Punjab, Pakistan to st... more A research trial was conducted at Rice Research Institute, Kala Shah Kaku, Punjab, Pakistan to study the population fluctuation of five species of rice pests namely white stem borer Scirpophaga innotata (Walker), yellow stem borer Scirpophaga incertulas (Walker), rice leaffolder, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae), whitebacked planthopper Sogatella furcifera (Horvath) (Homoptera: Delphacidae), and pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) on light trap. The effect of some abiotic factors like temperature, relative humidity and rainfall on the adult population of these pests was also studied. The population of these pests was monitored on the light trap from March to November from 2000 to 2014 in rice wheat cropping system. Yellow stem borer (YB), white stem borer (WB) and pink stem borer (PB) first appeared on the light trap in March when average temperature was 18°C. YB and WB had first peak population in mid-April at temperatures 30-33°C while second peak was observed in mid-September. Pink stem borer first peak population was observed in mid-March while second in mid-November. Rice leaffolder (RLF) started to appear in 3rd week of August. Peak population of whitebacked planthopper (WBPH) was observed in mid-October. Rainfall was found to be significantly positively correlated with WB population in March (0.821*) and October (0.884*). The population of yellow stem borer significantly and positively correlated with maximum temperature (0.773*) and minimum temperature (0.824*) in March and April respectively while it was negatively correlated with relative humidity (-0.832*) in April. Pink stem borer showed positive and significant relationship with rainfall (0.764*) and relative humidity (0.779*) in August and September respectively but negatively correlated with maximum temperature (-0.947**) in September. Rice leaffolder and whitebacked planthopper had positive and negative correlations with meteorological factors but they were non-significant.
The landfill garbage includes organic and inorganic matter. The organic matter covers more than 5... more The landfill garbage includes organic and inorganic matter. The organic matter covers more than 50% of the total waste material. Due to improper management of landfill garbage, it causes serious risks to human health directly by the emission of toxic gasses. On the other hand, landfill sites are the natural habitat of several microbes and arthropods. The present discussion illustrates the impact of landfill garbage on insect ecology and human health. Here, we highlighted the arthropod density as well as diversity. Moreover, the population of insect vectors of various diseases, insect scavengers as well as pollinators has been pinpointed. It shows that landfill sites and adjacent areas are hotspots for a wide variety of arthropods. The proper management of landfill sites could reduce the population dynamics of various insect pests, and health risks could be decreased in low-and middle-income countries.
Mosquitoes are the main vector of multiple diseases worldwide and transmit viral (malaria, chikun... more Mosquitoes are the main vector of multiple diseases worldwide and transmit viral (malaria, chikungunya, en-cephalitis, yellow fever, as well as dengue fever), as well as bacterial diseases (tularemia). To manage the outbreak of mosquito populations, various management programs include the application of chemicals, followed by biological and genetic control. Here we aimed to focus on the role of bacterial pathogenesis and molecular tactics for the management of mosquitoes and their vectorial capacity. Bacterial pathogenesis and molecular manipulations have a substantial impact on the biology of mosquitoes, and both strategies change the gene expression and regulation of disease vectors. The strategy for genetic modification is also proved to be excellent for the management of mosquitoes, which halt the development of population via incompatibility of different sex. Therefore, the purpose of the present discussion is to illustrate the impact of both approaches against the vectorial capacity of mosquitoes. Moreover, it could be helpful to understand the relationship of insect-pathogen and to manage various insect vectors as well as diseases.
International Journal of Tropical Insect Science, 2020
Panonychus citri (citrus red mite) is a devastating pest of citrus orchards. The conventional che... more Panonychus citri (citrus red mite) is a devastating pest of citrus orchards. The conventional chemical acaricides have been strongly forbidden for the management of agricultural insect pests in China. Therefore, we evaluated the susceptibility of adult and nymphs P. citri in laboratory against eight isolates of four fungal species, Akanthomyces lecanii, Metarhizium anisopliae, Beauveria bassiana and Aschersonia aleyrodis. Each citrus seedling having 40 adults (2-d-old) and nymphs (on separate plants) were sprayed with isolates at the concentration of 10 4~1 0 8 conidia mLˉ1 whereas controlled seedlings were sprayed with 0.02% Tween-80. After 9 days of fungal exposure, the four fungal isolates caused more than 50% mortality of mites, such as; 85.6%, 87.9%, 64.6% and 79.7% by A. lecanii (V3450), B. bassiana (BFZ0409), M. anisopliae (MFZ0706) and A. aleyrodis (AsG0910), respectively. The nymphal mites were less susceptible to applied fungi compared to adults. The LC 50 s of the tested isolates were determined by the fitted time-concentration-mortality relationships, which declined over days after spray. LT 50 s were decreased with a high concentration of isolates. After the 9-d inoculation, two isolates of B. bassiana (BFZ0409 and D1344) and one isolate of A. lecanii (V3450) were highly effective at the minimal dose of LC 50 of 10 4 conidia mLˉ1 and are promising candidates to control mites, as compared to other tested fungal isolates.
Characterization of genetically modified plants producing bioactive compounds for human health: a... more Characterization of genetically modified plants producing bioactive compounds for human health: a systemic review. Abstract Increasing knowledge on plant biotechnology, nutrition and medicine has altered the concepts regarding food, health and agriculture. Researchers in medical biotechnology as well as plant biology are recommending the application of plant systems, their products such as phytoceuticals, foods and phytotherapy to perk up human health along with disease prevention and treatment. Plants derived pharmaceuticals offer numerous advantages over other techniques such as mammalian cell culture methods etc. These modern trends have highlighted potential targets for the blooming pharma industry based on plant biotechnology. Most early studies, as well as current work, focus on crops as well as non-crop transgenic plants expressing several advantageous proteins that can be extracted, processed and used in the treatment of different diseases. The major part of public opinion is positive regarding the competence of biotechnology for improving life quality and standards. But unfortunately, due to some ambiguities in consumer's mind, phytoceutical production from transgenic plants is a bit ignored field both at researcher and consumer end. This review tried to put on view and differentiate the production of phytoceuticals from transgenic plants concerning human health. Readers will find twenty years of progress on phytoceuticals and their relatedness to reported human disease studies as well as trials. It also covers a comparison of different techniques to distinguish the production of phytoceuticals from transgenics and issues along with existing regulations for their safety and commercialization.
The study was carried out in eight provinces of China, with 16 different localities. A total of 1... more The study was carried out in eight provinces of China, with 16 different localities. A total of 150 adult dam-selflies were collected for the study from the area. Mitochondrial (COI) was the target gene to sequence from all 51 representative samples of the entire collection. From the resulted sequences, ten species belonging to seven genera and four families were identified. The families are Calopterygidae, Coenagrinidae, Chlorocyphidae and Devadattiade. After alignment through BioEdit v6, MEGA7 was used for phylogenetic tree construction as well as the calculation of genetic divergence, whereas genetic diversity was calculated by DnaSP v5. All species from the respective families had clustered together within the groups, but divided into subgroups. Maximum genetic divergence (9.31%) was found in the genus Rhinocypha, followed by Hetaerina with (8.23%), while, minimum divergence was observed for the genus Ceriagrion (0.32%) followed by Ischnura (0.48%). However, significant genetic diversity was found for all sequences at 346 mutations confirmed by two tests, Tajima's D and Fu's Fs. Maximum genetic diversity among genera was also observed, the genus Hetaerina has maximum genetic diversity (181 mutations) followed by Rhinocypha (68 mutations) while minimum genetic diversity was observed for the genus Ceriagrion followed by Ischnura. The presented results showed a higher diversity of damselflies in the south China regions.
The Kingdom of Saudi Arabia (KSA) has a diverse fauna due to its peculiar position bordering the ... more The Kingdom of Saudi Arabia (KSA) has a diverse fauna due to its peculiar position bordering the Afrotropical, Oriental and Palaearctic zoogeographic zones. The present study reports the phylogenetics of five mosquito species belonging to five series of Anopheles (Cellia) . We collected mosquito larvae from eastern, western and southwestern regions of KSA. The sampled mosquitoes were morphologically dentified using the pictorial keys of mosquitoes and characterized by using single and multi-locus analysis of -internal transcribed spacer 2 (ITS2) region and cytochrome oxidase c subunit I (COI). Based on the morphological and molecular data, five species were recognized, like An. stephensi Neocellia) (Oriental), An. arabiensis (Pyretophorus) (Afrotropical), An. dthali (Myzomyia) (Oriental and Palaearctic), An. cinereus Paramyzomyia) and An. rhodesiensis rupicola (Neomyzomyia) (Oriental and Palaearctic). The phylogenetic analysis showed that An. stephensi is a mono-phyletic species with different ecotypes found in different geographic regions. Comprehensive phylogenetics and population genetics studies are crucial for a better understanding of the role of these five mosquito species in malarial transmission across various zoogeographic zones of different ecological and demographic character- istics.
The inoculation methods, the fungal strains, and several other factors are known to influent the ... more The inoculation methods, the fungal strains, and several other factors are known to influent the success of fungal entomopathogens colonization in plants. The physiological status of the plant could also be another determinant. In the present study, the ability of three strains of Beauveria bassiana and one strain of Metarhizium anisopliae to successfully colonize Citrus limon plants and the influence of seedling age on endophytic colonization success was examined. Three, 4, and 6 months old seedlings were inoculated with 10 mL of 1 × 10 8 conidial·mL −1 suspensions of each of the four fungal strains via foliar spraying. All fungal strains successfully colonized citrus seedlings and were sustained up to 2 months in colonized plants irrespective of the seedling age, with differences in the mean percentage colonization recorded at various post-inoculation periods among the fungal strains. The highest percent endophytic fungi recovery rate was recorded in the 3 months old seedlings, where fungal mycelia of inoculated fungi were successfully re-isolated from 65.6% of the untreated newly developed leaf and stem tissues. One strain of B. bassiana, BB Fafu-12, significantly improved seedling height and leaf number. The study demonstrates the influence of seedling age on B. bassiana and M. anisopliae successful colonization in the citrus plant.
The cotton mealybug, Phenacoccus solenopsis, is an invasive pest that can cause massive damage to... more The cotton mealybug, Phenacoccus solenopsis, is an invasive pest that can cause massive damage to many host plants of agricultural importance. P. solenopsis is highly polyphagous, and shows extreme sexual dimorphism between males and females. The functions of DNA methyltransferase (DNMT) enzymes in the cotton mealybug have not been well studied. Here, we carried out an investigation of DNMTs in cotton mealybug to study their roles in sexual dimorphism. We found that the cotton mealybug has two copies of PsDnmt1, but Dnmt3 is absent. We then amplified the full-length cDNAs of PsDnmt1A (2,225 bp) and PsDnmt1B (2,862 bp) using rapid amplification cDNA ends (RACE). Quantitative reverse transcriptase PCR shows that both PsDnmt1A and PsDnmt1B are highly expressed in adult males, while the expression of PsDnmt1B is 30-fold higher in gravid females than in virgin females. We knocked down PsDnmt1A and PsDnmt1B with small interfering RNAs (siRNAs), and both genes were successfully down-regulated after 24 h or 72 h in adult females and pupa (t-test, p < 0.05). Down-regulating the expression of these two DNMT genes led to offspring lethality and abnormal body color in adult females. Furthermore, the silencing of PsDnmt1B induced abnormal wing development in emerged adult males. Our results provide evidence that PsDnmt1 plays a crucial role in regulating sexual dimorphism in the cotton mealybug.
Tamarixia radiata is one of the established biocontrol pests against the major Asian citrus psyll... more Tamarixia radiata is one of the established biocontrol pests against the major Asian citrus psyllid, Diaphorina citri, a vector of Candidatus Liberibacter that is a causal agent of citrus Huanglongbing (HLB) disease. Updated information and regional exploration on biocontrol pests are important elements for effective disease management strategies. In this study, the diversity and parasitism rate of T. radiata populations were evaluated. Due to the importance of the host–parasitoid relationship, the presence of Wolbachia as an endosymbiont was also investigated. The parasitism rate of various T. radiata populations from Ecuador and China ranged between 57.27% and 66.32%, respectively, with a non-significant emergence rate and a statistically similar sex ratio. Sequence analysis of ITS and COI from T. radiata populations was consistent with the morphological hypothesis that the collections represent a single species, whereas phylogeny of the wsp gene confirmed the presence of Wolbachia pipientis as an endosymbiont within T. radiata populations. Based on partial COI sequences, the maximum genetic diversity such as total haplotype diversity (Hd = 0.788), nucleotide, diversity (π = 0.2439), and average nucleotide difference (k = 171.844) was also estimated for different T. radiata populations. Furthermore, neutrality tests based on COI sequences indicated an overall contraction in T. radiata populations, whereas an expansion trend was observed in associated W. pipientis strains. This study clearly demonstrated the presence of genetically diverse T. radiata populations that were able to parasitize D. citri effectively, and these can be further explored as promising biocontrol candidates in integrated pest management strategies to solve citriculture economic loss caused by D. citri.
Bactrocera zonata (Saunders) and Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) are major pe... more Bactrocera zonata (Saunders) and Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) are major pests of fruits especially guava, posing a trade barrier of Pakistani fruits in foreign markets. Mass trapping of this pest by suitable selection of traps is necessary for its management by the male annihilation technique (MAT). Experiments were conducted in three different guava-producing districts of Punjab, i.e., Faisalabad, Sargodha, and Toba Tek Singh. Three locations in each district were selected for the experiment, three acres each. Three types of traps were used: the round trap (RT), the jar trap (JT), and the pet bottle trap (PBT), with six traps per acre. Multiple linear regression equations and correlations were computed on the mean population data for all traps in each year. April, May, and June (standard weeks 13-23) were fruit fly peak activity periods in all districts. Temperature exerted a highly significant and positive impact on fruit fly populations. Humidity was not significant, but showed a positive relationship with per unit population fluctuation. Rainfall was also not significant, but showed a negative relationship with per unit population fluctuation. The maximum impact of temperature was 43.5 and 42.8% in Faisalabad, the maximum impact of relative humidity was 26.2 and 22.2% in Sargodha, Faisalabad, and the maximum impact of rainfall was 26.3 and 15.1% in Sargodha. The PBT trap had significant and positive correlations with per unit population fluctuation in all three districts during 2015 and 2016. Pet bottle traps gave the maximum adult catches at all districts with minimum cost 13.30 $/ha in a year, which is suitable for farmer’s community to be used in a prediction model.
The current study was conducted to assess the impact of powdery mildew (Oidium neolycopersici) on... more The current study was conducted to assess the impact of powdery mildew (Oidium neolycopersici) on plant-non-vector herbivore-parasitoid interactions, e.g. tomato plants, whiteflies (Trialeurodes vaporariorum) and parasitoid (Encarsia formosa). Encarsia females were significantly less attracted to powdery mildew infected tomato plants (PM) than healthy plants (Con.). Thus parasitism rates of whiteflies (WF) were significantly lower on powdery mildew (PM) plants as compared to Con. plants (17.5:41.5%). These differences disappeared when E. formosa females were forced to parasitize whiteflies on either PM or Con. The performance of the parasitoid was not significantly influenced when developing on whiteflies feeding on powdery mildew infected plants. In olfactometer bioassays, either naïve or experienced parasitoids significantly preferred healthy plants colonised by whiteflies as compared to powdery mildew infected plants colonised by whitefly (PMWF) (30.0:10.0% for naïve parasitoids; 41.4:15.2% for experienced parasitoids). In wind tunnel bioassays, volatiles emitting from WFs significantly increased upwind oriented flight and landing in Encarsia targets as compared to any other treatments. Volatiles from Con, PM, PMWF and WF were collected and analyzed by GC and GC-MS, revealing that both qualities and quantities of volatile compounds differed to a large extend. Plants significantly increased volatile emission after being attacked by whiteflies (275.3 mol h−1) or infected by powdery mildew (267.58 mol h−1). However, plants significantly reduced volatile emissions in PMWF co-existing systems (80.58 mol h−1). Our results demonstrate that volatiles released by either herbivore damaged plants, pathogen diseased plants or combinations of these agents, respectively, may influence the foraging behavior of the parasitoids while searching for their hosts, resulting in reduced efficacies of parasitoids. This, in turn, may impact the outcome of biological control systems, especially in greenhouse conditions.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
This study was executed to assess the disruption in nutritional attributes of Capsicum annuum by ... more This study was executed to assess the disruption in nutritional attributes of Capsicum annuum by five different microplastic (MP) types i.e. polyvinylchloride (PVC), polystyrene (PS), high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polyethylene terephthalate (PET). Significant (P 0.05) differences were recorded among traits of C. annuum fruit concerning the type of MPs. PVC was more hazardous than the other MPs and depleted maximum protein content. Likewise, HDPE exerted a 51.62% reduction in carbohydrates compared to the control. Vitamin-A (-32.09%) and vitamin-B6 (-37%) were severely influenced by the PVC in C. annuum fruit. HDPE and PVC both declined the oleic acid contents. PVC caused a 47.6% reduction in linoleic acid while the least damaging was the PET (4.71%) for this attribute. Palmitic acid and stearic acid were however more negatively affected by the HDPE. The PVC and HDPE severely degraded the total flavonoid contents and phenolics. Macro and micronutrients of C. annuum fruit were also negatively influenced by all the five MPs used in this study. HDPE, PVC and LDPE, respectively caused significant repression in Ca, K, Mg and Zn (P 0.05). Overall, HDPE and PVC caused significant damage and decreased nutritional contents. This is, so far, the premier study unraveling the changes in the nutrition of C. annuum fruits due to MPs. Accordingly, further research is highly recommended on the changes caused by MPs in the nutritional value of food crops.
Plants, being sessile in nature, are inept to escape biotic stress that adversely impact their gr... more Plants, being sessile in nature, are inept to escape biotic stress that adversely impact their growth, development, and productivity. Rather, plants employ a variety of processes at the molecular, morphological, physiological as well as biochemical levels to mitigate the negative impacts of such stressors. Plants have a complex defense system against pathogens, pests and diseases, which includes collaborative actions regulated by array of genes and transcription factors. Immunity against pathogenic attack is determined by the plant's ability to avoid early infection and limit the growth of harmful pathogens, whereas resistance to microbial toxins is determined by the capacity of plant tissues to reduce toxin accumulation and its detoxification. This ability can be achieved through modulations in multiple processes. Among these processes, regulation of the antioxidant defense system, generation of reactive oxygen species and production of secondary metabolites is reckoned as an essential component of defense mechanism. Antioxidants such as superoxide dismutase (SOD), peroxidase (POD) and secondary metabolites, specifically phenolics, terpenes, and nitrogen-containing compounds have been widely proven to defend plants against range of biotic stresses. It is essentially needed to improve existing management practices to control pathogens and breed immunity in crops for sustainable agriculture and food security. Particularly to improve resistance to pathogenesis, the breeding of long-term resilience in cereals genotypes is one of the most promising strategies. A better grasp of the molecular processes underlying plant resilience to microbial assault will cast light on plant-pathogen interactions and provide useful information for breeding programs. This review emphasizes the ongoing investigation and significant operation of key molecular, physiological, and biochemical factors for tolerance and resistance in Oryza sativa against microbial infections. Additionally, we have focused on secondary metabolites and antioxidant defense system playing a crucial role in deciding how plants react to pathogen attacks.
Microbial pathogens attack every plant tissue, including leaves, roots, shoots, and flowers durin... more Microbial pathogens attack every plant tissue, including leaves, roots, shoots, and flowers during all growth stages. Thus, they cause several diseases resulting in a plant's failure or loss of the whole crop in severe cases. To combat the pathogens attack, plants produce some biologically active toxic compounds known as saponins. The saponins are secondary metabolic compounds produced in healthy plants with potential anti-pathogenic activity and serve as potential chemical barriers against pathogens. Saponins are classified into two major groups the steroidal and terpenoid saponins. Here, we reported the significance of saponin toxins in the war against insect pests, fungal, and bacterial pathogens. Saponins are present in both cultivated (chilies, spinach, soybean, quinoa, onion, oat, tea, etc.) and wild plant species. As they are natural toxic constituents of plant defense, breeders and plant researchers aiming to boost plant imm unity should focus on transferring these compounds in cash crops.
The recent outbreak of Covid-19 is posing a severe threat to public health globally. Coronaviruse... more The recent outbreak of Covid-19 is posing a severe threat to public health globally. Coronaviruses (CoVs) are the largest known group of positive-sense RNA viruses surviving on an extensive number of natural hosts. CoVs are enveloped and non-segmented viruses with a size between 80 and 120 nm. CoV attachment to the surface receptor and its subsequent entrance into cells is mediated by Spike glycoprotein (S). For enhanced CoV entry and successful pathogenesis of CoV, proteolytic processing and receptor-binding act synergistically for induction of large-scale S conformational changes. The shape, size and orientation of receptor-binding domains in viral attachment proteins are well conserved among viruses of different classes that utilize the same receptor. Therefore, investigations unraveling the distribution of cellular receptors with respect to CoV entry, structural aspects of glycoproteins and related conformational changes are highly significant for understanding virus invasion and infection spread. We present the characteristic features of CoV S-Proteins, their significance for CoVs and related receptor binding activities for pathogenesis and viral survival. We are analyzing the novel role of S-protein of CoVs along with their interactive receptors for improving host immunity and decreasing infection spread. This is hoped that presented information will open new ways in tackling coronavirus, especially for the ongoing epidemic.
International Journal of Tropical Insect Science, 2020
Worldwide, stored products are attacked by a large number of pests resulting in significant econo... more Worldwide, stored products are attacked by a large number of pests resulting in significant economic losses. Among these stored grain pests, khapra beetle, Trogoderma granarium (Everts) (Coleoptera: Dermestidae) is one of the top ranked pests that has ability to survive under diverse climate conditions. The management of this pest is mainly done by using synthetic chemicals which have side effects on consumers, ecosystem and non-target organisms. However, phyto-derivatives were found to be the effective environment friendly alternatives against T. granarium. Therefore, in this review, success of phyto-derivatives against khapra beetle from conventional means to modern research has been critically analyzed, summarized and discussed. In context, the different life stages of the insect starting from egg laying to adult development have been briefly explained. The review focuses upon recent research conducted on the evaluation of dozens of phyto-derivatives. In addition, the article has also highlighted some limitations of plant derived compounds and concludes via hoping that the future formulated pesticides will be safer, economical, least toxic to human and our planet ecosystem.
American bollworm (ABW), Helicoverpa armigera (Hubner), is considered as a major pest of cotton, ... more American bollworm (ABW), Helicoverpa armigera (Hubner), is considered as a major pest of cotton, Gossyp-ium hirsutum, all over the globe. Due to its destructive feeding nature and continuous consumption of the same chemicals, it devolved resistant against many insecticides. Therefore, a combined application of bio-and synthetic-pesticide need to evaluate against this pest. The entomopathogenic viruses like nuclear polyhedrosis virus (NPV), a member of baculoviruses, can be the potential candidates for better control against ABW. The present study was conducted to assess the comparative efficacy of NPV and Spinosad 240SC (with the concentration of 250 mL · ha − l) against ABW in the controlled environment. The ABW was treated with different concentrations of NPV and Spinosad separately and in a combination of NPV with 0.1% Spinosad. The results revealed that highest concentrations showed highest mortality (95%) followed by 95%, 92%, 84%, 82% and 78% mortality at 1 × 10 9 , 1 × 10 8 , 1 × 10 7 , 1 × 10 6 and 1 × 10 5 POBs, respectively. Spinosad when mixed in diet give 100% mortality at 0.8% followed by 50.87%, 42.10%, 29.82%, 26.31% and 22.80% mortality at 0.4%, 0.2%, 0.1%, 0.5% and 0.025% respectively. The results of this study revealed that microbial control of ABW through NPV is an effective tool. The repeated use of synthetic pesticides caused the resurgence of many insect pests, and this study results would provide useful insight to build a framework for future investigations for the management of many major insect pests.
The house fly, Musca domestica L. (Diptera: Muscidae), is a major pest of all aspects of life, li... more The house fly, Musca domestica L. (Diptera: Muscidae), is a major pest of all aspects of life, like the domestic, medical and veterinary and causal agent of several pathogenic diseases. The present study was conducted to evaluate the potential of different insecticide-free baits against house fly by incorporating flower methanol extract of Helianthus annuus (sunflower) and Tegetes erecta (marigold) at 10%, 20% and 30% bait formulation of corn syrup, dried milk and water. However, imidacloprid and thiacloprid (each at 5% concentration) were also included in the study for comparison. Results showed that insecticide baits were superior in causing mortality of adult house fly but dependent upon syrup. Overall, 20% baits of both extracts caused more than half population death of house fly within 48h. On the other hand, the mortality rate by 30% baits (from sunflower and marigold) had a similar impact as observed in case of imidacloprid and thiacloprid baits. Therefore, biological baits could play a more active and safer role in the management of house fly as compared to synthetic insecticides.
A research trial was conducted at Rice Research Institute, Kala Shah Kaku, Punjab, Pakistan to st... more A research trial was conducted at Rice Research Institute, Kala Shah Kaku, Punjab, Pakistan to study the population fluctuation of five species of rice pests namely white stem borer Scirpophaga innotata (Walker), yellow stem borer Scirpophaga incertulas (Walker), rice leaffolder, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae), whitebacked planthopper Sogatella furcifera (Horvath) (Homoptera: Delphacidae), and pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) on light trap. The effect of some abiotic factors like temperature, relative humidity and rainfall on the adult population of these pests was also studied. The population of these pests was monitored on the light trap from March to November from 2000 to 2014 in rice wheat cropping system. Yellow stem borer (YB), white stem borer (WB) and pink stem borer (PB) first appeared on the light trap in March when average temperature was 18°C. YB and WB had first peak population in mid-April at temperatures 30-33°C while second peak was observed in mid-September. Pink stem borer first peak population was observed in mid-March while second in mid-November. Rice leaffolder (RLF) started to appear in 3rd week of August. Peak population of whitebacked planthopper (WBPH) was observed in mid-October. Rainfall was found to be significantly positively correlated with WB population in March (0.821*) and October (0.884*). The population of yellow stem borer significantly and positively correlated with maximum temperature (0.773*) and minimum temperature (0.824*) in March and April respectively while it was negatively correlated with relative humidity (-0.832*) in April. Pink stem borer showed positive and significant relationship with rainfall (0.764*) and relative humidity (0.779*) in August and September respectively but negatively correlated with maximum temperature (-0.947**) in September. Rice leaffolder and whitebacked planthopper had positive and negative correlations with meteorological factors but they were non-significant.
The landfill garbage includes organic and inorganic matter. The organic matter covers more than 5... more The landfill garbage includes organic and inorganic matter. The organic matter covers more than 50% of the total waste material. Due to improper management of landfill garbage, it causes serious risks to human health directly by the emission of toxic gasses. On the other hand, landfill sites are the natural habitat of several microbes and arthropods. The present discussion illustrates the impact of landfill garbage on insect ecology and human health. Here, we highlighted the arthropod density as well as diversity. Moreover, the population of insect vectors of various diseases, insect scavengers as well as pollinators has been pinpointed. It shows that landfill sites and adjacent areas are hotspots for a wide variety of arthropods. The proper management of landfill sites could reduce the population dynamics of various insect pests, and health risks could be decreased in low-and middle-income countries.
Mosquitoes are the main vector of multiple diseases worldwide and transmit viral (malaria, chikun... more Mosquitoes are the main vector of multiple diseases worldwide and transmit viral (malaria, chikungunya, en-cephalitis, yellow fever, as well as dengue fever), as well as bacterial diseases (tularemia). To manage the outbreak of mosquito populations, various management programs include the application of chemicals, followed by biological and genetic control. Here we aimed to focus on the role of bacterial pathogenesis and molecular tactics for the management of mosquitoes and their vectorial capacity. Bacterial pathogenesis and molecular manipulations have a substantial impact on the biology of mosquitoes, and both strategies change the gene expression and regulation of disease vectors. The strategy for genetic modification is also proved to be excellent for the management of mosquitoes, which halt the development of population via incompatibility of different sex. Therefore, the purpose of the present discussion is to illustrate the impact of both approaches against the vectorial capacity of mosquitoes. Moreover, it could be helpful to understand the relationship of insect-pathogen and to manage various insect vectors as well as diseases.
International Journal of Tropical Insect Science, 2020
Panonychus citri (citrus red mite) is a devastating pest of citrus orchards. The conventional che... more Panonychus citri (citrus red mite) is a devastating pest of citrus orchards. The conventional chemical acaricides have been strongly forbidden for the management of agricultural insect pests in China. Therefore, we evaluated the susceptibility of adult and nymphs P. citri in laboratory against eight isolates of four fungal species, Akanthomyces lecanii, Metarhizium anisopliae, Beauveria bassiana and Aschersonia aleyrodis. Each citrus seedling having 40 adults (2-d-old) and nymphs (on separate plants) were sprayed with isolates at the concentration of 10 4~1 0 8 conidia mLˉ1 whereas controlled seedlings were sprayed with 0.02% Tween-80. After 9 days of fungal exposure, the four fungal isolates caused more than 50% mortality of mites, such as; 85.6%, 87.9%, 64.6% and 79.7% by A. lecanii (V3450), B. bassiana (BFZ0409), M. anisopliae (MFZ0706) and A. aleyrodis (AsG0910), respectively. The nymphal mites were less susceptible to applied fungi compared to adults. The LC 50 s of the tested isolates were determined by the fitted time-concentration-mortality relationships, which declined over days after spray. LT 50 s were decreased with a high concentration of isolates. After the 9-d inoculation, two isolates of B. bassiana (BFZ0409 and D1344) and one isolate of A. lecanii (V3450) were highly effective at the minimal dose of LC 50 of 10 4 conidia mLˉ1 and are promising candidates to control mites, as compared to other tested fungal isolates.
Characterization of genetically modified plants producing bioactive compounds for human health: a... more Characterization of genetically modified plants producing bioactive compounds for human health: a systemic review. Abstract Increasing knowledge on plant biotechnology, nutrition and medicine has altered the concepts regarding food, health and agriculture. Researchers in medical biotechnology as well as plant biology are recommending the application of plant systems, their products such as phytoceuticals, foods and phytotherapy to perk up human health along with disease prevention and treatment. Plants derived pharmaceuticals offer numerous advantages over other techniques such as mammalian cell culture methods etc. These modern trends have highlighted potential targets for the blooming pharma industry based on plant biotechnology. Most early studies, as well as current work, focus on crops as well as non-crop transgenic plants expressing several advantageous proteins that can be extracted, processed and used in the treatment of different diseases. The major part of public opinion is positive regarding the competence of biotechnology for improving life quality and standards. But unfortunately, due to some ambiguities in consumer's mind, phytoceutical production from transgenic plants is a bit ignored field both at researcher and consumer end. This review tried to put on view and differentiate the production of phytoceuticals from transgenic plants concerning human health. Readers will find twenty years of progress on phytoceuticals and their relatedness to reported human disease studies as well as trials. It also covers a comparison of different techniques to distinguish the production of phytoceuticals from transgenics and issues along with existing regulations for their safety and commercialization.
The study was carried out in eight provinces of China, with 16 different localities. A total of 1... more The study was carried out in eight provinces of China, with 16 different localities. A total of 150 adult dam-selflies were collected for the study from the area. Mitochondrial (COI) was the target gene to sequence from all 51 representative samples of the entire collection. From the resulted sequences, ten species belonging to seven genera and four families were identified. The families are Calopterygidae, Coenagrinidae, Chlorocyphidae and Devadattiade. After alignment through BioEdit v6, MEGA7 was used for phylogenetic tree construction as well as the calculation of genetic divergence, whereas genetic diversity was calculated by DnaSP v5. All species from the respective families had clustered together within the groups, but divided into subgroups. Maximum genetic divergence (9.31%) was found in the genus Rhinocypha, followed by Hetaerina with (8.23%), while, minimum divergence was observed for the genus Ceriagrion (0.32%) followed by Ischnura (0.48%). However, significant genetic diversity was found for all sequences at 346 mutations confirmed by two tests, Tajima's D and Fu's Fs. Maximum genetic diversity among genera was also observed, the genus Hetaerina has maximum genetic diversity (181 mutations) followed by Rhinocypha (68 mutations) while minimum genetic diversity was observed for the genus Ceriagrion followed by Ischnura. The presented results showed a higher diversity of damselflies in the south China regions.
The Kingdom of Saudi Arabia (KSA) has a diverse fauna due to its peculiar position bordering the ... more The Kingdom of Saudi Arabia (KSA) has a diverse fauna due to its peculiar position bordering the Afrotropical, Oriental and Palaearctic zoogeographic zones. The present study reports the phylogenetics of five mosquito species belonging to five series of Anopheles (Cellia) . We collected mosquito larvae from eastern, western and southwestern regions of KSA. The sampled mosquitoes were morphologically dentified using the pictorial keys of mosquitoes and characterized by using single and multi-locus analysis of -internal transcribed spacer 2 (ITS2) region and cytochrome oxidase c subunit I (COI). Based on the morphological and molecular data, five species were recognized, like An. stephensi Neocellia) (Oriental), An. arabiensis (Pyretophorus) (Afrotropical), An. dthali (Myzomyia) (Oriental and Palaearctic), An. cinereus Paramyzomyia) and An. rhodesiensis rupicola (Neomyzomyia) (Oriental and Palaearctic). The phylogenetic analysis showed that An. stephensi is a mono-phyletic species with different ecotypes found in different geographic regions. Comprehensive phylogenetics and population genetics studies are crucial for a better understanding of the role of these five mosquito species in malarial transmission across various zoogeographic zones of different ecological and demographic character- istics.
The inoculation methods, the fungal strains, and several other factors are known to influent the ... more The inoculation methods, the fungal strains, and several other factors are known to influent the success of fungal entomopathogens colonization in plants. The physiological status of the plant could also be another determinant. In the present study, the ability of three strains of Beauveria bassiana and one strain of Metarhizium anisopliae to successfully colonize Citrus limon plants and the influence of seedling age on endophytic colonization success was examined. Three, 4, and 6 months old seedlings were inoculated with 10 mL of 1 × 10 8 conidial·mL −1 suspensions of each of the four fungal strains via foliar spraying. All fungal strains successfully colonized citrus seedlings and were sustained up to 2 months in colonized plants irrespective of the seedling age, with differences in the mean percentage colonization recorded at various post-inoculation periods among the fungal strains. The highest percent endophytic fungi recovery rate was recorded in the 3 months old seedlings, where fungal mycelia of inoculated fungi were successfully re-isolated from 65.6% of the untreated newly developed leaf and stem tissues. One strain of B. bassiana, BB Fafu-12, significantly improved seedling height and leaf number. The study demonstrates the influence of seedling age on B. bassiana and M. anisopliae successful colonization in the citrus plant.
The cotton mealybug, Phenacoccus solenopsis, is an invasive pest that can cause massive damage to... more The cotton mealybug, Phenacoccus solenopsis, is an invasive pest that can cause massive damage to many host plants of agricultural importance. P. solenopsis is highly polyphagous, and shows extreme sexual dimorphism between males and females. The functions of DNA methyltransferase (DNMT) enzymes in the cotton mealybug have not been well studied. Here, we carried out an investigation of DNMTs in cotton mealybug to study their roles in sexual dimorphism. We found that the cotton mealybug has two copies of PsDnmt1, but Dnmt3 is absent. We then amplified the full-length cDNAs of PsDnmt1A (2,225 bp) and PsDnmt1B (2,862 bp) using rapid amplification cDNA ends (RACE). Quantitative reverse transcriptase PCR shows that both PsDnmt1A and PsDnmt1B are highly expressed in adult males, while the expression of PsDnmt1B is 30-fold higher in gravid females than in virgin females. We knocked down PsDnmt1A and PsDnmt1B with small interfering RNAs (siRNAs), and both genes were successfully down-regulated after 24 h or 72 h in adult females and pupa (t-test, p < 0.05). Down-regulating the expression of these two DNMT genes led to offspring lethality and abnormal body color in adult females. Furthermore, the silencing of PsDnmt1B induced abnormal wing development in emerged adult males. Our results provide evidence that PsDnmt1 plays a crucial role in regulating sexual dimorphism in the cotton mealybug.
Insect herbivores are dangerous to all stages of plants, e.g., vegetative as well as reproductive... more Insect herbivores are dangerous to all stages of plants, e.g., vegetative as well as reproductive growth, leaves and shoots. Some of the herbivores feed by sucking plant sap, whereas some insects choose to chew various parts of plants. Thus, all types of herbivores damage the plant by feeding directly and cause multiple diseases to plants, leading to plant damage indirectly. However, due to insect attack, plants produce some bioactive compounds (which are known as saponins) to improve their defense mechanism against herbivores. These saponins are further divided into two main categories, e.g., steroidal saponins and terpenoidal saponins. Here, we have highlighted the importance of saponins from multiple plant families against various herbivores. Saponins are present in different wild plants as well as cultivated crops (e.g., soybeans, tea, spinach, oats, peppers, capsicum, quinoa, and alliums). Some of the saponins play a role as antifeedant, while some are insecticidal to different life stages of insect pests. Thus, these saponins play an important role in the plant defense against different insect pests. Moreover, different saponins are effective against stored grain pests as well as cosmopolitan insect pests. Therefore, these plant bioactive compounds could be helpful for integrated pest management in different ecosystems.
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Paramyzomyia) and An. rhodesiensis rupicola (Neomyzomyia) (Oriental and Palaearctic). The phylogenetic analysis showed that An. stephensi is a mono-phyletic species with different ecotypes found in different geographic regions. Comprehensive phylogenetics and population genetics studies are crucial for a better understanding of the role of these five mosquito species in malarial transmission across various zoogeographic zones of different ecological and demographic character-
istics.
Paramyzomyia) and An. rhodesiensis rupicola (Neomyzomyia) (Oriental and Palaearctic). The phylogenetic analysis showed that An. stephensi is a mono-phyletic species with different ecotypes found in different geographic regions. Comprehensive phylogenetics and population genetics studies are crucial for a better understanding of the role of these five mosquito species in malarial transmission across various zoogeographic zones of different ecological and demographic character-
istics.