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Monitoring of the Indian meal moth and its parasitoids in long-term grain storage
Get PDFThe Indian meal moth Plodia interpunctella became a major pest in bulk grain storage in Germany in recent years. Monitoring with adhesive pheromone-baited traps revealed a dependence of the number of generations of the moth from the temperature conditions in store, which themselves depend on insulation of the storage structure. The larval parasitoid Habrobracon hebetor was monitored with the help of cone traps placed in the grain. Baiting these traps with moth webbings significantly increased the number of female wasps trapped in 5 cm depth in wheat. Field trials showed both the pest and the beneficial can be monitored in stores, but more research is needed to develop a biological control strategy for P. interpunctella.The Indian meal moth Plodia interpunctella became a major pest in bulk grain storage in Germany in recent years. Monitoring with adhesive pheromone-baited traps revealed a dependence of the number of generations of the moth from the temperature conditions in store, which themselves depend on insulation of the storage structure. The larval parasitoid Habrobracon hebetor was monitored with the help of cone traps placed in the grain. Baiting these traps with moth webbings significantly increased the number of female wasps trapped in 5 cm depth in wheat. Field trials showed both the pest and the beneficial can be monitored in stores, but more research is needed to develop a biological control strategy for P. interpunctella
Improved analysis of propylene oxide, propylene chlorohydrin and propylene bromohydrin: Presentation
Get PDFThe benefits and deficiencies of several methods of analysis for PPO and PXH, including the aqueous extraction used in ASTA method 23.1 and the MTBE extraction method previously reported by the authors, will be discussed. Novel methods utilizing dynamic headspace extraction and solid phase microextraction (SPME) will also be reported with particular emphasis on preventing artefactual effects. Preliminary experiments have found that dynamic headspace sampling can lower detection limits by up to 3 orders of magnitude.The benefits and deficiencies of several methods of analysis for PPO and PXH, including the aqueous extraction used in ASTA method 23.1 and the MTBE extraction method previously reported by the authors, will be discussed. Novel methods utilizing dynamic headspace extraction and solid phase microextraction (SPME) will also be reported with particular emphasis on preventing artefactual effects. Preliminary experiments have found that dynamic headspace sampling can lower detection limits by up to 3 orders of magnitude
Spinosad-induced stress on the maize weevil Sitophilus zeamais: Presentation
No full textAlthough seldom considered, sublethal insecticide exposure may lead to harmful, neutral, or even beneficial responses that may affect (or not) the behavior and fitness of the exposed insects. Intriguingly, little is known about such effects on stored product insect pests and even less is available regarding the bioinsecticide, spinosad. Thus, we assessed the sublethal effects of spinosad on walking, feeding, drinking and mating behaviors of maize weevils (Sitophilus zeamais), also assessing their survival, reproductive output, and grain loss compared with maize weevils exposed to the pyrethroid deltamethrin (as positive control), and water only (negative control). Both spinosad and deltamethrin were able to effectively control the insects, although the latter caused a faster mortality than the former. Behavioral pattern changes were caused by both insecticides, especially deltamethrin, triggering irritability (i.e., avoidance after contact). Different feeding and drinking responses were also detected with significant avoidance to deltamethrin, but not to spinosad. Maize weevil couples sublethally exposed to deltamethrin and spinosad exhibited altered reproductive behavior, a likely consequence of their altered activity, but deltamethrin caused greater behavioral changes. Curiously, higher progeny emergence and grain loss were observed in deltamethrin-exposed insects, suggesting that this pyrethroid insecticide elicits hormesis in maize weevils that may compromise control efficacy by this compound. In contrast, such effect was not detected with spinosad, which did not elicit avoidance allowing the intended weevil exposure and control.Although seldom considered, sublethal insecticide exposure may lead to harmful, neutral, or even beneficial responses that may affect (or not) the behavior and fitness of the exposed insects. Intriguingly, little is known about such effects on stored product insect pests and even less is available regarding the bioinsecticide, spinosad. Thus, we assessed the sublethal effects of spinosad on walking, feeding, drinking and mating behaviors of maize weevils (Sitophilus zeamais), also assessing their survival, reproductive output, and grain loss compared with maize weevils exposed to the pyrethroid deltamethrin (as positive control), and water only (negative control). Both spinosad and deltamethrin were able to effectively control the insects, although the latter caused a faster mortality than the former. Behavioral pattern changes were caused by both insecticides, especially deltamethrin, triggering irritability (i.e., avoidance after contact). Different feeding and drinking responses were also detected with significant avoidance to deltamethrin, but not to spinosad. Maize weevil couples sublethally exposed to deltamethrin and spinosad exhibited altered reproductive behavior, a likely consequence of their altered activity, but deltamethrin caused greater behavioral changes. Curiously, higher progeny emergence and grain loss were observed in deltamethrin-exposed insects, suggesting that this pyrethroid insecticide elicits hormesis in maize weevils that may compromise control efficacy by this compound. In contrast, such effect was not detected with spinosad, which did not elicit avoidance allowing the intended weevil exposure and control
Effects of different inert dusts on Sitophilus oryzae and Plodia interpunctella during contact exposure: Poster
No full textThe use of natural inert dusts against storage insect pests is increasing recently, as an alternative to conventional insecticides. Laboratory study was carried out to evaluate the contact effect of three inert dusts, diatomaceous earth (DE), kaoline (KA) and vermiculite (VE), at rates 5, 7.5, 10, 15 and 20 gm-2, against adults of Sitophilus oryzae (L.) and larvae of Plodia interpunctella (Hubner). Insect mortality was evaluated 1, 2, 3 and 7 days after the exposure. Insect mortality varied depending on the species, concentrations and exposure periods. The DE and KA caused 86.7-98% mortality of S. oryzae after 2 days of exposure at the highest rates, while at 5 and 7.5 gm-2, 100% mortality was achieved only after 7 days. The highest rates of inert dusts caused 42-50% (DE) and 60-75% (KA) mortality of P. interpunctella larvae only after 7days. The mortality of moths increased gradually with the concentration and 100% was achieved 3 days after the contact with DE and KA (10, 15 and 20 g m-2). However, inert dusts induced faster pupation of P. interpunctella, while adult emergence was reduced and adults had smaller body-sizes, compared to control. The VE caused relatively low mortalities (7-11% of S. oryzae adults and 5-8% of P. interpunctella larvae) at all tested rates during the entire experiment. Our results have shown good insecticidal effect of DE and KA against S. oryzae and P. interpunctella at 10, 15 and 20 gm-2. These products could therefore be used by small-scale farmers to protect stored grains against insect pest infestation.The use of natural inert dusts against storage insect pests is increasing recently, as an alternative to conventional insecticides. Laboratory study was carried out to evaluate the contact effect of three inert dusts, diatomaceous earth (DE), kaoline (KA) and vermiculite (VE), at rates 5, 7.5, 10, 15 and 20 gm-2, against adults of Sitophilus oryzae (L.) and larvae of Plodia interpunctella (Hubner). Insect mortality was evaluated 1, 2, 3 and 7 days after the exposure. Insect mortality varied depending on the species, concentrations and exposure periods. The DE and KA caused 86.7-98% mortality of S. oryzae after 2 days of exposure at the highest rates, while at 5 and 7.5 gm-2, 100% mortality was achieved only after 7 days. The highest rates of inert dusts caused 42-50% (DE) and 60-75% (KA) mortality of P. interpunctella larvae only after 7days. The mortality of moths increased gradually with the concentration and 100% was achieved 3 days after the contact with DE and KA (10, 15 and 20 g m-2). However, inert dusts induced faster pupation of P. interpunctella, while adult emergence was reduced and adults had smaller body-sizes, compared to control. The VE caused relatively low mortalities (7-11% of S. oryzae adults and 5-8% of P. interpunctella larvae) at all tested rates during the entire experiment. Our results have shown good insecticidal effect of DE and KA against S. oryzae and P. interpunctella at 10, 15 and 20 gm-2. These products could therefore be used by small-scale farmers to protect stored grains against insect pest infestation
Evaluation of the suitability and optimal use of postharvest storage bag technologies and a combination thereof for maize storage in Nigeria.: Presentation
Get PDFThe severity of postharvest losses varies considerably depending on storage method and prevalence of storage insect pests known to bore into storage bags. Polypropylene (PP) bags used by smallholder farmers in Nigeria do not provide effective protection for stored produce due to insect boring activities. Deltamethrin incorporated polypropylene, ZeroFly® (ZF) and ZeroFly® Hermetic Storage Bags are technologies with potential to improve protection of stored food commodities against insect attack. Therefore, a 12-month study was conducted in Ibadan, Nigeria to determine the suitability and potential of combined postharvest bag technologies involving ZeroFly® (hermetic and non-hermetic) bags for smallholder farmers when exposed to Sitophilus zeamais and Prostephanus truncatus infestation pressure. Cleaned but un-fumigated 50-kg lots of maize were used to fill bags in each of the following 8 treatments — PP and ZF bags alone, diatomaceous earth-treated maize in PP and ZF bags, single and double hermetic liners in ZF bags, single hermetic liner in PP bags and lastly PICS bags. Results obtained over a 12-month period showed infestation by S. zeamais, Tribolium castaneum, Cryptolestes ferrugineus and Liposcelis spp. and abundance of insect increased with storage period in PP and ZF bags without liner. The percentages of insect damaged kernels by number (IDK) were higher in PP and ZF bags without liner and were 5.4 and 16.9%, respectively; in ZeroFly bags with hermetic liners, these values were ~ 0.5%. The PP and ZF bags without liner also had higher weight loss values of 1.4 and 6.7%, respectively compared with ZeroFly bags with hermetic liners and PICS bags which had a relatively lower weight loss of =0.2%. These results indicate that the ZeroFly Hermetic bag mitigates insect infestations, thereby offering a suitable alternative towards achieving significant reduction in postharvest losses during storage.The severity of postharvest losses varies considerably depending on storage method and prevalence of storage insect pests known to bore into storage bags. Polypropylene (PP) bags used by smallholder farmers in Nigeria do not provide effective protection for stored produce due to insect boring activities. Deltamethrin incorporated polypropylene, ZeroFly® (ZF) and ZeroFly® Hermetic Storage Bags are technologies with potential to improve protection of stored food commodities against insect attack. Therefore, a 12-month study was conducted in Ibadan, Nigeria to determine the suitability and potential of combined postharvest bag technologies involving ZeroFly® (hermetic and non-hermetic) bags for smallholder farmers when exposed to Sitophilus zeamais and Prostephanus truncatus infestation pressure. Cleaned but un-fumigated 50-kg lots of maize were used to fill bags in each of the following 8 treatments — PP and ZF bags alone, diatomaceous earth-treated maize in PP and ZF bags, single and double hermetic liners in ZF bags, single hermetic liner in PP bags and lastly PICS bags. Results obtained over a 12-month period showed infestation by S. zeamais, Tribolium castaneum, Cryptolestes ferrugineus and Liposcelis spp. and abundance of insect increased with storage period in PP and ZF bags without liner. The percentages of insect damaged kernels by number (IDK) were higher in PP and ZF bags without liner and were 5.4 and 16.9%, respectively; in ZeroFly bags with hermetic liners, these values were ~ 0.5%. The PP and ZF bags without liner also had higher weight loss values of 1.4 and 6.7%, respectively compared with ZeroFly bags with hermetic liners and PICS bags which had a relatively lower weight loss of =0.2%. These results indicate that the ZeroFly Hermetic bag mitigates insect infestations, thereby offering a suitable alternative towards achieving significant reduction in postharvest losses during storage
Insecticide treated packaging for the control of stored product insects: Presentation
No full textImproper or poor post-harvest handling and storage of stored grains contributes significantly to product loss, and bagged stored grain presents an option for safe storage and handling. Bagged grain is intended to maintain quality and safety, while protecting it from infestations. The objective of this research was to determine the effect of deltamethrin-treated packaging material on adults and larvae of common stored product pests. Adults or larvae of several species of stored product insects were exposed to deltamethrin-treated packaging for time intervals ranging from 1 h to 4 weeks. The percentage of affected Prostephanus truncatus, Callosobruchus maculatus and Rhyzopertha dominica adults was < 98% after 60 minutes of exposure to treated packaging. Mortality of adult Trogoderma granarium was about 33% after 1 day of exposure, and increased to 93% after 7 day of exposure. Direct mortality of T. granarium larvae exposed to the deltamethrin-treated packaging for 8 h was about 15%, but increased to 50% when larvae were exposed for 72 h. Tribolium castaneum, Oryzaephilus surinamensis, and Trogoderma inclusum larvae continually exposed to the deltamethrin-treated packaging resulted in > 96% larval death within 1-2 weeks.The major primary stored product insects were highly susceptible to the deltamethrin-treated storage bags, but there was variation in susceptibility between species and life stages tested. The deltamethrin-treated storage bags can offer protection of bagged grains and be used as a preventative measure to reduce infestations during storage.Improper or poor post-harvest handling and storage of stored grains contributes significantly to product loss, and bagged stored grain presents an option for safe storage and handling. Bagged grain is intended to maintain quality and safety, while protecting it from infestations. The objective of this research was to determine the effect of deltamethrin-treated packaging material on adults and larvae of common stored product pests. Adults or larvae of several species of stored product insects were exposed to deltamethrin-treated packaging for time intervals ranging from 1 h to 4 weeks. The percentage of affected Prostephanus truncatus, Callosobruchus maculatus and Rhyzopertha dominica adults was < 98% after 60 minutes of exposure to treated packaging. Mortality of adult Trogoderma granarium was about 33% after 1 day of exposure, and increased to 93% after 7 day of exposure. Direct mortality of T. granarium larvae exposed to the deltamethrin-treated packaging for 8 h was about 15%, but increased to 50% when larvae were exposed for 72 h. Tribolium castaneum, Oryzaephilus surinamensis, and Trogoderma inclusum larvae continually exposed to the deltamethrin-treated packaging resulted in > 96% larval death within 1-2 weeks.The major primary stored product insects were highly susceptible to the deltamethrin-treated storage bags, but there was variation in susceptibility between species and life stages tested. The deltamethrin-treated storage bags can offer protection of bagged grains and be used as a preventative measure to reduce infestations during storage
Recent developments in the global application of ECO2FUME® and VAPORPH3OS® phosphine fumigants: Presentation
Get PDFECO2FUME® (2% phosphine, 98% CO2 by weight) and VAPORPH3OS® (99.3% phosphine average by weight) are cylinderized gas formulations of phosphine that have achieved significant growth in commercial applications for the disinfestation of food and non-food commodities in the last two decades. The expansion in the global application of these two cylinderized phosphine fumigants is driven by increasing concern for safety, efficacy, unreacted powdered residue and disposal associated with aluminium phosphide tablets, which are promoted as alternatives to methyl bromide, and the concern of insect resistance to phosphine in both developed and developing countries. This paper describes recent developments in the global application of ECO2FUME® and VAPORPH3OS® in terms of commercial in-transit fumigation of grains and logs in ships, fumigation of export distiller’s dried grain with solubles (DDGS) in containers and shiphold, best practices in the management of phosphine resistance of insects in grains, and establishment and application of quarantine and preshipment (QPS) phosphine fumigation protocols for selected fresh fruits, vegetables, dried fruits and cut flowers as an alternative to methyl bromide. The growing issue of powdered residue from unspent aluminium phosphine tablets and the use of cylinderized phosphine as an effective solution are discussed.ECO2FUME® (2% phosphine, 98% CO2 by weight) and VAPORPH3OS® (99.3% phosphine average by weight) are cylinderized gas formulations of phosphine that have achieved significant growth in commercial applications for the disinfestation of food and non-food commodities in the last two decades. The expansion in the global application of these two cylinderized phosphine fumigants is driven by increasing concern for safety, efficacy, unreacted powdered residue and disposal associated with aluminium phosphide tablets, which are promoted as alternatives to methyl bromide, and the concern of insect resistance to phosphine in both developed and developing countries. This paper describes recent developments in the global application of ECO2FUME® and VAPORPH3OS® in terms of commercial in-transit fumigation of grains and logs in ships, fumigation of export distiller’s dried grain with solubles (DDGS) in containers and shiphold, best practices in the management of phosphine resistance of insects in grains, and establishment and application of quarantine and preshipment (QPS) phosphine fumigation protocols for selected fresh fruits, vegetables, dried fruits and cut flowers as an alternative to methyl bromide. The growing issue of powdered residue from unspent aluminium phosphine tablets and the use of cylinderized phosphine as an effective solution are discussed
The Postharvest Education Foundation’s role in reducing postharvest losses: Poster
Get PDFThe Postharvest Education Foundation (PEF) was founded to address postharvest losses through education and training. Postharvest expertisewas identified as a key weakness in many developing countries. The PEF provides innovative programs that motivate and empower people to reduce food losses and waste. At the heart of the PEF is a structured e-learning program that provides a practical curriculum to address the causes of postharvest losses, as well as methods to minimize these losses for horticultural crops and staple foods. E-learning is an efficient and cost-effective way to reach interested parties globally, and keeping costs low enables PEF to train and mentor a large number of candidates in developing countries. The curriculum entails several assignments and participants can conduct these assignments on a crop of their choice, making the training relevant to their situations. Most of the 154 people who have completed the program have in turn trained hundreds of farmers, traders and marketers in their own regions inhandling fresh produce, crop storage, and food processing, thereby delivering maximum impact with minimum input. In addition to its e-learning program, the PEF provides education on improved technical practices along the postharvest chain and on extension education. This training includes a wide range of topics from measuring postharvestlosses to designing demonstrations on storage, pest management, packaging and temperature management, from building and using low cost cold storage systems to calculating return on investment of changes in handling practices. The PEF also provides advice on designing postharvest training and service centers. This information is available on the organization’s website. In addition, mentoring is provided through social media sites, continuing with the philosophy of providing distance education and training.The Postharvest Education Foundation (PEF) was founded to address postharvest losses through education and training. Postharvest expertisewas identified as a key weakness in many developing countries. The PEF provides innovative programs that motivate and empower people to reduce food losses and waste. At the heart of the PEF is a structured e-learning program that provides a practical curriculum to address the causes of postharvest losses, as well as methods to minimize these losses for horticultural crops and staple foods. E-learning is an efficient and cost-effective way to reach interested parties globally, and keeping costs low enables PEF to train and mentor a large number of candidates in developing countries. The curriculum entails several assignments and participants can conduct these assignments on a crop of their choice, making the training relevant to their situations. Most of the 154 people who have completed the program have in turn trained hundreds of farmers, traders and marketers in their own regions inhandling fresh produce, crop storage, and food processing, thereby delivering maximum impact with minimum input. In addition to its e-learning program, the PEF provides education on improved technical practices along the postharvest chain and on extension education. This training includes a wide range of topics from measuring postharvestlosses to designing demonstrations on storage, pest management, packaging and temperature management, from building and using low cost cold storage systems to calculating return on investment of changes in handling practices. The PEF also provides advice on designing postharvest training and service centers. This information is available on the organization’s website. In addition, mentoring is provided through social media sites, continuing with the philosophy of providing distance education and training
Qualitative discussion about reducing grain postharvest loss with mobile storage in Ghana, West Africa
Get PDFFarming sustainably and protecting gross harvest production correctly provides growers with “health care, school fees and peace-of-mind” (net benefits). Reducing Postharvest and input loss sustains the components of agriculture’s triple-bottom-line which are “accessible nutrition, reduced green-house emissions, and foreign exchange reserves”. Lacking storage that stops grain PHL, agriculture suffers critical problems like the Aspergillus fungi that leaves grain contaminated with invisible aflatoxin that growers cannot consume or market. The objective of the Ghana pilot study was to understand why new ideas/findings like, applying biologicals to the soil before harvest, gross production inputs, virtual markets and especially the spread of stationary grain warehouses have failed to improve the net benefits of farming or agricultures’ triple-bottomline in sub-Saharan Africa. Qualitative comparison methods were used to identify roadblocks to improvement as scientific monitoring and storage eliminate grain Postharvest loss on the drylands in many parts of the world. Observations suggest net benefits are being ignored as reviews and assessments of primitive or council storage exchange scientific rigor for Stationary Warehouse Prejudice. Scientific rigor illuminates how the qualitative cost of aflatoxin, and quantitative expense of pests, recycling plastic, and empty stationary warehouses impact enduser- cost per unit stored per month. We conclude that Postharvest loss is expensive, and that relatively inexpensive mobile metal storage assets would improve net benefits and the triple-bottom-line.Farming sustainably and protecting gross harvest production correctly provides growers with “health care, school fees and peace-of-mind” (net benefits). Reducing Postharvest and input loss sustains the components of agriculture’s triple-bottom-line which are “accessible nutrition, reduced green-house emissions, and foreign exchange reserves”. Lacking storage that stops grain PHL, agriculture suffers critical problems like the Aspergillus fungi that leaves grain contaminated with invisible aflatoxin that growers cannot consume or market. The objective of the Ghana pilot study was to understand why new ideas/findings like, applying biologicals to the soil before harvest, gross production inputs, virtual markets and especially the spread of stationary grain warehouses have failed to improve the net benefits of farming or agricultures’ triple-bottomline in sub-Saharan Africa. Qualitative comparison methods were used to identify roadblocks to improvement as scientific monitoring and storage eliminate grain Postharvest loss on the drylands in many parts of the world. Observations suggest net benefits are being ignored as reviews and assessments of primitive or council storage exchange scientific rigor for Stationary Warehouse Prejudice. Scientific rigor illuminates how the qualitative cost of aflatoxin, and quantitative expense of pests, recycling plastic, and empty stationary warehouses impact enduser- cost per unit stored per month. We conclude that Postharvest loss is expensive, and that relatively inexpensive mobile metal storage assets would improve net benefits and the triple-bottom-line
Susceptibility of phosphine-resistant cigarette beetles to various insecticides: Poster
Get PDFManagement of phosphine resistance in the cigarette beetle Lasioderma serricorne (F.) has become a topic of great interest to the tobacco industry in recent years. Effective use of contact insecticides with modes of action different from that of phosphine can be a key element in preventing or delaying the evolution of phosphine resistance. This study was conducted to ascertain whether five insecticides selected from three mode-of-action classes (fenitrothion, pirimiphos-methyl, permethrin, bifenthrin, and spinosad) can be incorporated into a phosphine-resistance management strategy. Specifically, we examined the contact efficacy of the insecticides to a phosphine-susceptible strain and six resistant strains (38–184-fold in resistance ratio based on LC50). Susceptibility to organophosphates (fenitrothion, pirimiphos-methyl) and spinosad was not significantly different between phosphine-susceptible and phosphine-resistant strains (within 2.3-fold resistance ratio). The absence of the cross-resistance between these insecticides and phosphine makes them ideal for resistancemanagement programmes. However, high resistance to synthetic pyrethroids (>145-fold for permethrin and >1697-fold for bifenthrin) was found in three of six phosphine-resistant strains. Based on these results, synthetic pyrethroids cannot be recommended as insecticides of primary choice.Management of phosphine resistance in the cigarette beetle Lasioderma serricorne (F.) has become a topic of great interest to the tobacco industry in recent years. Effective use of contact insecticides with modes of action different from that of phosphine can be a key element in preventing or delaying the evolution of phosphine resistance. This study was conducted to ascertain whether five insecticides selected from three mode-of-action classes (fenitrothion, pirimiphos-methyl, permethrin, bifenthrin, and spinosad) can be incorporated into a phosphine-resistance management strategy. Specifically, we examined the contact efficacy of the insecticides to a phosphine-susceptible strain and six resistant strains (38–184-fold in resistance ratio based on LC50). Susceptibility to organophosphates (fenitrothion, pirimiphos-methyl) and spinosad was not significantly different between phosphine-susceptible and phosphine-resistant strains (within 2.3-fold resistance ratio). The absence of the cross-resistance between these insecticides and phosphine makes them ideal for resistancemanagement programmes. However, high resistance to synthetic pyrethroids (>145-fold for permethrin and >1697-fold for bifenthrin) was found in three of six phosphine-resistant strains. Based on these results, synthetic pyrethroids cannot be recommended as insecticides of primary choice