FIGURE 13. Typhlodromus (Anthoseius) daresalaami El-Banhawy & Abou-Awad (female): A. Dorsal shiel... more FIGURE 13. Typhlodromus (Anthoseius) daresalaami El-Banhawy & Abou-Awad (female): A. Dorsal shield; B. Ventral surface; C. Spermatheca; D. Leg IV.
FIGURE 1. Typhlodromus (Anthoseius) acaciae Schultz: Female—A. Dorsal shield; B. Ventral surface;... more FIGURE 1. Typhlodromus (Anthoseius) acaciae Schultz: Female—A. Dorsal shield; B. Ventral surface; C. Chelicera; D. Spermatheca; E. Leg IV; Male—F. Spermatodactyl; G. Ventrianal shield.
Plant-based foods may serve as alternative resources in meeting the nutritional requirements of p... more Plant-based foods may serve as alternative resources in meeting the nutritional requirements of predatory mites, when the preferred prey species is scarce. In laboratory studies, we evaluated the effect of various plant-based food resources associated with cassava on development and reproduction of Neoseiulus (=Amblyseius) idaeus Denmark and Muma, Typhlodromalus manihoti Moraes, and Typhlodromalus aripo DeLeon, three predatory mites that have
New cassava varieties were developed by IITA in order to improve their agronomic yield, pest and ... more New cassava varieties were developed by IITA in order to improve their agronomic yield, pest and disease resistance, and micronutrient content (higher beta-carotene and other carotenoids). This study assessed the ability of 18 new released varieties to produce a traditional cassava food product named “bâton de manioc” in Cameroon central region, in order to maximize their chances of adoption by processors and consumers. Bâton is a steamed cassava mash wrapped in leaves of Megaphrynium macrostachyum, or leaves of other species of Marantaceae. The successive steps of the traditional process were described in details and data on processing yields, material balances, shaping and cooking conditions, as well as production capacity and product quality, were reported. Results showed that “bâton” with both better quality and productivity were obtained from varieties with lower fibre content and larger size of roots. The best profitability was obtained with varieties longer than 25 cm, with a diameter comprised between 6 and 9 cm and a weight comprised between 0.8 and 1.4 kg. Additionally, a survey with processors highlighted the desired quality criteria for cassava varieties to make a good “bâton”. Eight varieties out of the 18 were finally identified as able to be processed into a good “bâton”. Their acceptability by a large number of Cameroonian consumers will be tested in a further study. Beyond these initial results, the originality of the approach was to assess performance and quality criteria for cassava processing in local conditions, which appears very effective to ensure that improved varieties have appropriate characteristics for traditional uses, and also to integrate market and consumers' demands early in varietal improvement programs. (Resume d'auteur)
Two countrywide surveys were conducted in April-May and May-June 2004 throughout the cassava grow... more Two countrywide surveys were conducted in April-May and May-June 2004 throughout the cassava growing belt of Mozambique including several provinces: Gaza, Inhambane, Sofala, Manica, Zambezia, Nampula and Cabo Delgado. Both surveys were planned to assess the distribution, incidence and damage severity of diseases and pests that affect cassava production in Mozambique. Using the methodology developed by the International Institute of Tropical Agriculture (IITA), 202 and 175 cassava fields between 4-8 months old were sampled for pests and diseases in April-May 2003 and May-June 2004, respectively. The results of both surveys showed in the case of diseases that cassava mosaic disease (CMD) was found to be the most widespread disease in Mozambique although the distribution, incidence, and severity varied among provinces, among fields and within fields. The most severe damage was recorded in Gaza, Sofala and Nampula where the average scores were above 3 on a 1-5 damage scale but only in a limited number of sample fields. In other provinces, the disease was either absent or damage symptoms were slight to moderate (2-3). The DNA analysis of the leaf samples coIlected in 2004 throughout the country revealed the presence of several strains of CMD virus including, the African Cassava Mosaic Virus (ACMV), the Eastern African Cassava Mosaic Virus (EACMV), and a combination of both African and EastAfrican Cassava Mosaic Virus (ACMV+EACMV) in 80.5% and 7.6% of the field samples respectiveIy. The devastating East African Cassava Mosaic Virus - Ugandan Strain (EACMVUG2) was absent from all sampled fields. The presence of cassava brown streak disease (CBSD) was confirmed as a serious threat particularly in two of the three Northern provinces of Zambezia and Nampula and at lesser extent in Cabo Delgado. However, the severity was the highest in Zambezia and in the district of Nakala in Nampula province. The other known common tropical diseases of cassava such as the cassava bacterial blight (CBB) and cassava anthracnose disease (CAD) were of minor importance. The cassava green mite (CGM), Mononychellus tanajoa Bondar remained a problem in the southern provinces (Gaza, Inhambane) where the exotic predatory mites Typhlodromalus aripo De Leon was not yet established.. CGM infestations were followed by whitefly (WF) infestations in a rank-order hierarchy of infestation rates. Although generally known as vectors of the cassava mosaic disease (CMD), the high whitefly population densities recorded in some locations (>lo0 adults per plant, e.g. in Zambezia province), was considered a direct pest causing considerable leaf damage and covering plants with sooty molds. The incidence and damage severity of other common pests of cassava (i.e. cassava mealybug, termites, and grasshoppers) appeared insignificant
International journal of pest management, Oct 29, 2015
The cotton aphid (Aphis gossypii) is one of the major pests of okra. Eleven okra varieties collec... more The cotton aphid (Aphis gossypii) is one of the major pests of okra. Eleven okra varieties collected from farmers' fields in Cameroon and four aphid-resistant accessions from The World Vegetable Center (AVRDC, Asian Vegetable Research and Development Center) were evaluated from October 2012 to March 2013, and another seven aphid-resistant accessions from AVRDC were evaluated from March to July 2013 at AVRDC's Nkolbisson station, Yaoundé, Cameroon. Accessions selected from these trials were screened in an advanced confirmatory screening in autumn (October–December) 2013 in Shanhua, Taiwan. Results showed that none of the farmers' landraces were resistant to aphids. Two accessions (VI041210 and VI033824) with the lowest aphid populations had the highest trichome density. Analysis of various phytochemicals in selected okra accessions revealed that higher nitrogen and potassium levels made the okra accessions susceptible to aphids during the reproductive stage of the plants. Similarly, the total phenol content was lower in moderately resistant accessions during their reproductive stage. Aphid feeding induced an increase in phenols, and to a lesser extent, tannins. Accessions VI041210 and VI033824 could be incorporated into an integrated pest management strategy to enhance productivity of okra.
Diachasmimorpha longicaudata (Ashmead), a solitary koinobiont larval–prepupal endoparasitoid of f... more Diachasmimorpha longicaudata (Ashmead), a solitary koinobiont larval–prepupal endoparasitoid of fruit flies, was introduced into Kenya for testing and final release against the recently discovered invasive species, Bactrocera invadens Drew, Tsuruta and White in Africa. Laboratory experiments were conducted to determine host preference, host acceptability for oviposition and physiological suitability of B. invadens and five other indigenous tephritid fruit fly species –Ceratitis capitata (Wiedemann), Ceratitis cosyra (Walker), Ceratitis rosa Karsch, Ceratitis fasciventris (Bezzi) and Ceratitis anonae Graham – for the development of D. longicaudata. Females of D. longicaudata visited all host‐larval patches, and were also attracted to these hosts at comparable levels. Acceptability, successful development of parasitoid progenies and their sex ratio varied widely across hosts. C. capitata yielded the highest parasitoid numbers whereas B. invadens was the only host that yielded a female‐biased sex ratio. Larvae of B. invadens, C. rosa, C. fasciventris and C. anonae mounted differential immune reaction towards D. longicaudata eggs. Although, the parasitoid performed poorly on the target host B. invadens, it was able to form new association with C. cosyra and C. capitata. The prospect of using this parasitoid in biological control of African indigenous fruit flies is discussed.
FIGURE 13. Typhlodromus (Anthoseius) daresalaami El-Banhawy & Abou-Awad (female): A. Dorsal shiel... more FIGURE 13. Typhlodromus (Anthoseius) daresalaami El-Banhawy & Abou-Awad (female): A. Dorsal shield; B. Ventral surface; C. Spermatheca; D. Leg IV.
FIGURE 1. Typhlodromus (Anthoseius) acaciae Schultz: Female—A. Dorsal shield; B. Ventral surface;... more FIGURE 1. Typhlodromus (Anthoseius) acaciae Schultz: Female—A. Dorsal shield; B. Ventral surface; C. Chelicera; D. Spermatheca; E. Leg IV; Male—F. Spermatodactyl; G. Ventrianal shield.
Plant-based foods may serve as alternative resources in meeting the nutritional requirements of p... more Plant-based foods may serve as alternative resources in meeting the nutritional requirements of predatory mites, when the preferred prey species is scarce. In laboratory studies, we evaluated the effect of various plant-based food resources associated with cassava on development and reproduction of Neoseiulus (=Amblyseius) idaeus Denmark and Muma, Typhlodromalus manihoti Moraes, and Typhlodromalus aripo DeLeon, three predatory mites that have
New cassava varieties were developed by IITA in order to improve their agronomic yield, pest and ... more New cassava varieties were developed by IITA in order to improve their agronomic yield, pest and disease resistance, and micronutrient content (higher beta-carotene and other carotenoids). This study assessed the ability of 18 new released varieties to produce a traditional cassava food product named “bâton de manioc” in Cameroon central region, in order to maximize their chances of adoption by processors and consumers. Bâton is a steamed cassava mash wrapped in leaves of Megaphrynium macrostachyum, or leaves of other species of Marantaceae. The successive steps of the traditional process were described in details and data on processing yields, material balances, shaping and cooking conditions, as well as production capacity and product quality, were reported. Results showed that “bâton” with both better quality and productivity were obtained from varieties with lower fibre content and larger size of roots. The best profitability was obtained with varieties longer than 25 cm, with a diameter comprised between 6 and 9 cm and a weight comprised between 0.8 and 1.4 kg. Additionally, a survey with processors highlighted the desired quality criteria for cassava varieties to make a good “bâton”. Eight varieties out of the 18 were finally identified as able to be processed into a good “bâton”. Their acceptability by a large number of Cameroonian consumers will be tested in a further study. Beyond these initial results, the originality of the approach was to assess performance and quality criteria for cassava processing in local conditions, which appears very effective to ensure that improved varieties have appropriate characteristics for traditional uses, and also to integrate market and consumers' demands early in varietal improvement programs. (Resume d'auteur)
Two countrywide surveys were conducted in April-May and May-June 2004 throughout the cassava grow... more Two countrywide surveys were conducted in April-May and May-June 2004 throughout the cassava growing belt of Mozambique including several provinces: Gaza, Inhambane, Sofala, Manica, Zambezia, Nampula and Cabo Delgado. Both surveys were planned to assess the distribution, incidence and damage severity of diseases and pests that affect cassava production in Mozambique. Using the methodology developed by the International Institute of Tropical Agriculture (IITA), 202 and 175 cassava fields between 4-8 months old were sampled for pests and diseases in April-May 2003 and May-June 2004, respectively. The results of both surveys showed in the case of diseases that cassava mosaic disease (CMD) was found to be the most widespread disease in Mozambique although the distribution, incidence, and severity varied among provinces, among fields and within fields. The most severe damage was recorded in Gaza, Sofala and Nampula where the average scores were above 3 on a 1-5 damage scale but only in a limited number of sample fields. In other provinces, the disease was either absent or damage symptoms were slight to moderate (2-3). The DNA analysis of the leaf samples coIlected in 2004 throughout the country revealed the presence of several strains of CMD virus including, the African Cassava Mosaic Virus (ACMV), the Eastern African Cassava Mosaic Virus (EACMV), and a combination of both African and EastAfrican Cassava Mosaic Virus (ACMV+EACMV) in 80.5% and 7.6% of the field samples respectiveIy. The devastating East African Cassava Mosaic Virus - Ugandan Strain (EACMVUG2) was absent from all sampled fields. The presence of cassava brown streak disease (CBSD) was confirmed as a serious threat particularly in two of the three Northern provinces of Zambezia and Nampula and at lesser extent in Cabo Delgado. However, the severity was the highest in Zambezia and in the district of Nakala in Nampula province. The other known common tropical diseases of cassava such as the cassava bacterial blight (CBB) and cassava anthracnose disease (CAD) were of minor importance. The cassava green mite (CGM), Mononychellus tanajoa Bondar remained a problem in the southern provinces (Gaza, Inhambane) where the exotic predatory mites Typhlodromalus aripo De Leon was not yet established.. CGM infestations were followed by whitefly (WF) infestations in a rank-order hierarchy of infestation rates. Although generally known as vectors of the cassava mosaic disease (CMD), the high whitefly population densities recorded in some locations (>lo0 adults per plant, e.g. in Zambezia province), was considered a direct pest causing considerable leaf damage and covering plants with sooty molds. The incidence and damage severity of other common pests of cassava (i.e. cassava mealybug, termites, and grasshoppers) appeared insignificant
International journal of pest management, Oct 29, 2015
The cotton aphid (Aphis gossypii) is one of the major pests of okra. Eleven okra varieties collec... more The cotton aphid (Aphis gossypii) is one of the major pests of okra. Eleven okra varieties collected from farmers' fields in Cameroon and four aphid-resistant accessions from The World Vegetable Center (AVRDC, Asian Vegetable Research and Development Center) were evaluated from October 2012 to March 2013, and another seven aphid-resistant accessions from AVRDC were evaluated from March to July 2013 at AVRDC's Nkolbisson station, Yaoundé, Cameroon. Accessions selected from these trials were screened in an advanced confirmatory screening in autumn (October–December) 2013 in Shanhua, Taiwan. Results showed that none of the farmers' landraces were resistant to aphids. Two accessions (VI041210 and VI033824) with the lowest aphid populations had the highest trichome density. Analysis of various phytochemicals in selected okra accessions revealed that higher nitrogen and potassium levels made the okra accessions susceptible to aphids during the reproductive stage of the plants. Similarly, the total phenol content was lower in moderately resistant accessions during their reproductive stage. Aphid feeding induced an increase in phenols, and to a lesser extent, tannins. Accessions VI041210 and VI033824 could be incorporated into an integrated pest management strategy to enhance productivity of okra.
Diachasmimorpha longicaudata (Ashmead), a solitary koinobiont larval–prepupal endoparasitoid of f... more Diachasmimorpha longicaudata (Ashmead), a solitary koinobiont larval–prepupal endoparasitoid of fruit flies, was introduced into Kenya for testing and final release against the recently discovered invasive species, Bactrocera invadens Drew, Tsuruta and White in Africa. Laboratory experiments were conducted to determine host preference, host acceptability for oviposition and physiological suitability of B. invadens and five other indigenous tephritid fruit fly species –Ceratitis capitata (Wiedemann), Ceratitis cosyra (Walker), Ceratitis rosa Karsch, Ceratitis fasciventris (Bezzi) and Ceratitis anonae Graham – for the development of D. longicaudata. Females of D. longicaudata visited all host‐larval patches, and were also attracted to these hosts at comparable levels. Acceptability, successful development of parasitoid progenies and their sex ratio varied widely across hosts. C. capitata yielded the highest parasitoid numbers whereas B. invadens was the only host that yielded a female‐biased sex ratio. Larvae of B. invadens, C. rosa, C. fasciventris and C. anonae mounted differential immune reaction towards D. longicaudata eggs. Although, the parasitoid performed poorly on the target host B. invadens, it was able to form new association with C. cosyra and C. capitata. The prospect of using this parasitoid in biological control of African indigenous fruit flies is discussed.
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