Host plant species will influence the population and physiological performance of insects. Frankl... more Host plant species will influence the population and physiological performance of insects. Frankliniella occidentalis is a well-known invasive pest commonly found on flowering plants. Herein, the population development of F. occidentalis was investigated on the flowers of different Rosa chinensis cultivars (Ruby, Love, Parade, Pink Peace, and Mohana), and the digestive enzyme activities in thrips were measured after feeding on these flowers. The developmental times of F. occidentalis from egg to adult were 10.07, 10.37, 11.64, 10.66, and 10.90 d on Ruby, Love, Parade, Pink Peace, and Mohana, respectively. Significant differences in fecundity were also observed, with the greatest fecundity levels of F. occidentalis on Ruby (82.96) and the lowest on Mohana (63.40). F. occidentalis showed the greatest R0 on Ruby (43.57), followed by Love (36.46), Parade (33.00), Pink Peace (27.97), and Mohana (23.21). The rm showed a similar trend, with values of 0.156, 0.145, 0.141, 0.134, and 0.130, ...
Onion thrips, Thrips tabaci (Lindeman), is a major pest of dry bulb onion throughout the US and a... more Onion thrips, Thrips tabaci (Lindeman), is a major pest of dry bulb onion throughout the US and across the world. Yield and quality damage from thrips feeding and the expense of insecticides used for thrips management have jeopardized profitable and sustainable onion production. To improve approaches to thrips management, researchers in multiple US onion-producing regions developed novel, integrated pest management (IPM)-based strategies employing threshold-based insecticide treatments and reduced fertilization practices. The purpose of this study was to estimate the benefits from public investment in research to develop IPM-based onion thrips management techniques using a cost–benefit analysis. Benefits were extended over a 20-year timespan and were measured by reduced insecticide and fertilizer costs. The estimated net present value of benefits from improved pest management tactics will depend on the adoption and use of novel approaches to management. Using a scenario that assumes...
Groundnut ringspot virus was recently identified in tomatoes in South Florida — the first report ... more Groundnut ringspot virus was recently identified in tomatoes in South Florida — the first report in the United States. It can infect tomato plants at all stages of growth and lead to unmarketable fruits or plant death. This 4-page fact sheet shares what is known about the symptoms, host range, disease transmission, and management. Written by Eugene McAvoy, Scott Adkins, Craig Webster, Charles Mellinger, Loren Horsman, Galen Frantz, Stuart Reitz, and Shouan Zhang, and published by the UF Department of Plant Pathology, July 2011.
Psix saccharicola (Mani) and Trissolcus semistriatus (Nees) are the most abundant eggs parasitoid... more Psix saccharicola (Mani) and Trissolcus semistriatus (Nees) are the most abundant eggs parasitoids of the stink bug, Acrosternum arabicum Wagner, in pistachio orchards and have the potential to contribute to their suppression. However, treatment of orchards with broad-spectrum insecticides may greatly reduce populations of these beneficial natural enemies. Therefore, we conducted risk assessments and evaluated sublethal impacts of two insecticides routinely used in pistachio orchards: the organophosphate fenitrothion and a formulated mixture of the neonicotinoid thiamethoxam and the pyrethroid lambda-cyhalothrin on parasitism success, emergence and sex ratio of P. saccharicola and T. semistriatus. Based on the values of their risk quotients (RQ), which are derived from toxicity data, the two insecticide products would be classified as slightly-to-moderately toxic although an alternative metric, the safety factor (SF), showed them to be highly risky. Assessments of sublethal effects ...
Changing climate and land‐use practices have the potential to bring previously isolated populatio... more Changing climate and land‐use practices have the potential to bring previously isolated populations of pest insects into new sympatry. This heightens the need to better understand how differing patterns of host–plant association, and unique endosymbionts, serve to promote genetic isolation or integration. We addressed these factors in populations of potato psyllid, Bactericera cockerelli (Šulc), a generalist herbivore that vectors a bacterial pathogen (Candidatus Liberibacter solanacearum, causal pathogen of zebra chip disease) of potato (Solanum tuberosum L.). Genome‐wide SNP data revealed two major genetic clusters—psyllids collected from potato crops were genetically similar to psyllids found on a common weed, Lycium spp., but dissimilar from those found on another common non‐crop host, Solanum dulcamara L. Most psyllids found on Lycium spp. and potato represented a single mitochondrial cytochrome oxidase I (COI) haplotype that has been suggested to not be native to the region, a...
The potato tuber moth, Phthorimaea operculella, is the most damaging potato pest in the world and... more The potato tuber moth, Phthorimaea operculella, is the most damaging potato pest in the world and is difficult to control as the larvae are internal feeders in the foliage or tubers. Entomopathogenic fungi (EPF) which colonize plants as endophytes, have lethal and sublethal pathological effects on insect pests. Experiments showed that Beauveria bassiana colonized the aerial parts of potato plants endophytically after inoculation through soil drenching. The colonization rate reached 100% for both upper and lower foliage parts one day after inoculation, and endophytic B. bassiana remained present for more than 21-day post inoculation. Mortality experiments indicated that B. bassiana and B. bassiana-inoculated potato plants were pathogenic against 2nd instar larvae of P. operculella. Development experiments showed that the weight of P. operculella pupae reared on B. bassiana-colonized potato leaves (4.25 mg) was significantly lighter than of those reared on uninoculated control plants ...
Pistacia vera L. is one of the most important horticultural crops in Iran. The stink bugs Acroste... more Pistacia vera L. is one of the most important horticultural crops in Iran. The stink bugs Acrosternum arabicum and Brachynema germari are two of the key pests that cause significant direct and indirect damage on Pistacia vera. Egg parasitoids have been considered as potential biological control agents of pistachio green stink bugs. Among them, Trissolcus semistriatus and Psix saccharicola are the most abundant and efficient parasitoid for A. arabicum in pistachio orchards. In this study, we assessed lethal and sublethal effects of two commonly used insecticide products (fenitrothion and a binary mixture of lambda-cyhalothrin + thiamethoxam) on these two parasitoid wasps under laboratory conditions. The median lethal concentration (LC50) values for fenitrothion and thiamethoxam + lambda-cyhalothrin in P. saccharicola and T. semistriatus were estimated as 1.03, 0.48 and 0.87, 0.98 mg a.i./liter, respectively. In terms of sublethal effects, insecticide treatments altered the type of fu...
Host plant species will influence the population and physiological performance of insects. Frankl... more Host plant species will influence the population and physiological performance of insects. Frankliniella occidentalis is a well-known invasive pest commonly found on flowering plants. Herein, the population development of F. occidentalis was investigated on the flowers of different Rosa chinensis cultivars (Ruby, Love, Parade, Pink Peace, and Mohana), and the digestive enzyme activities in thrips were measured after feeding on these flowers. The developmental times of F. occidentalis from egg to adult were 10.07, 10.37, 11.64, 10.66, and 10.90 d on Ruby, Love, Parade, Pink Peace, and Mohana, respectively. Significant differences in fecundity were also observed, with the greatest fecundity levels of F. occidentalis on Ruby (82.96) and the lowest on Mohana (63.40). F. occidentalis showed the greatest R0 on Ruby (43.57), followed by Love (36.46), Parade (33.00), Pink Peace (27.97), and Mohana (23.21). The rm showed a similar trend, with values of 0.156, 0.145, 0.141, 0.134, and 0.130, ...
Onion thrips, Thrips tabaci (Lindeman), is a major pest of dry bulb onion throughout the US and a... more Onion thrips, Thrips tabaci (Lindeman), is a major pest of dry bulb onion throughout the US and across the world. Yield and quality damage from thrips feeding and the expense of insecticides used for thrips management have jeopardized profitable and sustainable onion production. To improve approaches to thrips management, researchers in multiple US onion-producing regions developed novel, integrated pest management (IPM)-based strategies employing threshold-based insecticide treatments and reduced fertilization practices. The purpose of this study was to estimate the benefits from public investment in research to develop IPM-based onion thrips management techniques using a cost–benefit analysis. Benefits were extended over a 20-year timespan and were measured by reduced insecticide and fertilizer costs. The estimated net present value of benefits from improved pest management tactics will depend on the adoption and use of novel approaches to management. Using a scenario that assumes...
Groundnut ringspot virus was recently identified in tomatoes in South Florida — the first report ... more Groundnut ringspot virus was recently identified in tomatoes in South Florida — the first report in the United States. It can infect tomato plants at all stages of growth and lead to unmarketable fruits or plant death. This 4-page fact sheet shares what is known about the symptoms, host range, disease transmission, and management. Written by Eugene McAvoy, Scott Adkins, Craig Webster, Charles Mellinger, Loren Horsman, Galen Frantz, Stuart Reitz, and Shouan Zhang, and published by the UF Department of Plant Pathology, July 2011.
Psix saccharicola (Mani) and Trissolcus semistriatus (Nees) are the most abundant eggs parasitoid... more Psix saccharicola (Mani) and Trissolcus semistriatus (Nees) are the most abundant eggs parasitoids of the stink bug, Acrosternum arabicum Wagner, in pistachio orchards and have the potential to contribute to their suppression. However, treatment of orchards with broad-spectrum insecticides may greatly reduce populations of these beneficial natural enemies. Therefore, we conducted risk assessments and evaluated sublethal impacts of two insecticides routinely used in pistachio orchards: the organophosphate fenitrothion and a formulated mixture of the neonicotinoid thiamethoxam and the pyrethroid lambda-cyhalothrin on parasitism success, emergence and sex ratio of P. saccharicola and T. semistriatus. Based on the values of their risk quotients (RQ), which are derived from toxicity data, the two insecticide products would be classified as slightly-to-moderately toxic although an alternative metric, the safety factor (SF), showed them to be highly risky. Assessments of sublethal effects ...
Changing climate and land‐use practices have the potential to bring previously isolated populatio... more Changing climate and land‐use practices have the potential to bring previously isolated populations of pest insects into new sympatry. This heightens the need to better understand how differing patterns of host–plant association, and unique endosymbionts, serve to promote genetic isolation or integration. We addressed these factors in populations of potato psyllid, Bactericera cockerelli (Šulc), a generalist herbivore that vectors a bacterial pathogen (Candidatus Liberibacter solanacearum, causal pathogen of zebra chip disease) of potato (Solanum tuberosum L.). Genome‐wide SNP data revealed two major genetic clusters—psyllids collected from potato crops were genetically similar to psyllids found on a common weed, Lycium spp., but dissimilar from those found on another common non‐crop host, Solanum dulcamara L. Most psyllids found on Lycium spp. and potato represented a single mitochondrial cytochrome oxidase I (COI) haplotype that has been suggested to not be native to the region, a...
The potato tuber moth, Phthorimaea operculella, is the most damaging potato pest in the world and... more The potato tuber moth, Phthorimaea operculella, is the most damaging potato pest in the world and is difficult to control as the larvae are internal feeders in the foliage or tubers. Entomopathogenic fungi (EPF) which colonize plants as endophytes, have lethal and sublethal pathological effects on insect pests. Experiments showed that Beauveria bassiana colonized the aerial parts of potato plants endophytically after inoculation through soil drenching. The colonization rate reached 100% for both upper and lower foliage parts one day after inoculation, and endophytic B. bassiana remained present for more than 21-day post inoculation. Mortality experiments indicated that B. bassiana and B. bassiana-inoculated potato plants were pathogenic against 2nd instar larvae of P. operculella. Development experiments showed that the weight of P. operculella pupae reared on B. bassiana-colonized potato leaves (4.25 mg) was significantly lighter than of those reared on uninoculated control plants ...
Pistacia vera L. is one of the most important horticultural crops in Iran. The stink bugs Acroste... more Pistacia vera L. is one of the most important horticultural crops in Iran. The stink bugs Acrosternum arabicum and Brachynema germari are two of the key pests that cause significant direct and indirect damage on Pistacia vera. Egg parasitoids have been considered as potential biological control agents of pistachio green stink bugs. Among them, Trissolcus semistriatus and Psix saccharicola are the most abundant and efficient parasitoid for A. arabicum in pistachio orchards. In this study, we assessed lethal and sublethal effects of two commonly used insecticide products (fenitrothion and a binary mixture of lambda-cyhalothrin + thiamethoxam) on these two parasitoid wasps under laboratory conditions. The median lethal concentration (LC50) values for fenitrothion and thiamethoxam + lambda-cyhalothrin in P. saccharicola and T. semistriatus were estimated as 1.03, 0.48 and 0.87, 0.98 mg a.i./liter, respectively. In terms of sublethal effects, insecticide treatments altered the type of fu...
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