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Evaluation of the difference in the development of stored insect pests on organic litter: Poster
Get PDFOn July 2017 in a warehouse of pet food shop in Italy an infestation of Oryzaephilus surinamensis was found on a pallet of organic litter, near an infested pallet of dog’s pasta. In order to investigate the origin of the infestation, and to support the risk assessment by the pest control operator, one test was conducted at Agroblu Laboratory of Applied Entomology (LEAA) to observe the feasibility of development of O. surinamensis, Plodia interpunctella and Tribolium confusum, in a substrate of 2,5 g of organic litter and to compare it to a balanced diet substrate. The results showed that only T. confusum was able to develop with no statistical difference both on the breeding diet and the organic litter.On July 2017 in a warehouse of pet food shop in Italy an infestation of Oryzaephilus surinamensis was found on a pallet of organic litter, near an infested pallet of dog’s pasta. In order to investigate the origin of the infestation, and to support the risk assessment by the pest control operator, one test was conducted at Agroblu Laboratory of Applied Entomology (LEAA) to observe the feasibility of development of O. surinamensis, Plodia interpunctella and Tribolium confusum, in a substrate of 2,5 g of organic litter and to compare it to a balanced diet substrate. The results showed that only T. confusum was able to develop with no statistical difference both on the breeding diet and the organic litter
Comparison of mandible morphology of two stored product bostrichid beetles, Rhyzopertha dominica and Prostephanus truncatus: Poster
No full textInsect mandibles are most frequently encountered fragments in processed foods. Thanks to their sclerotised and darkly pigmented nature, they usually remain intact in foods and are relatively easily detectable. Moreover, because of their complexity and variety of shapes, stored product beetle mandibles may be useful in species determination. The present work deals with a comparative morphology of two stored product bostrichid beetles, Rhyzopertha dominica and Prostephanus truncatus. The mandibles were studied using by light and scanning electron microscopy and their morphological details, overall appearance and size are provided.Insect mandibles are most frequently encountered fragments in processed foods. Thanks to their sclerotised and darkly pigmented nature, they usually remain intact in foods and are relatively easily detectable. Moreover, because of their complexity and variety of shapes, stored product beetle mandibles may be useful in species determination. The present work deals with a comparative morphology of two stored product bostrichid beetles, Rhyzopertha dominica and Prostephanus truncatus. The mandibles were studied using by light and scanning electron microscopy and their morphological details, overall appearance and size are provided
Survey of Trogoderma species (Coleoptera: Dermestidae) associated with international trade of dried distiller’s grains and solubles in the USA: Presentation
Get PDFDried distiller’s grains and solubles, DDGS, is a valuable commodity with substantial international trade. Vietnam discovered an infestation of Trogoderma inclusum, an actionable quarantine pest, in DDGS from the USA in 2012. All subsequent shipments to Vietnam were required to be fumigated. A shipment to Vietnam from the USA 2015 was then discovered with T. variabile. We surveyed the presence and activity of T. inclusum and T. variabile at locations in the USA that provide DDGSs for shipment to Vietnam. Seven facilities in four states that either produced DDGSs or that facilitated bulk shipments were studied. Pheromone traps were deployed at each location and monitored for several weeks. T. variaible was trapped at all seven sites while T. inclusum was trapped at just five of these. T. variabile were captured in nearly every trapping period and at higher numbers than T. inclusum at five locations, while two locations captured more T. inclusum than T. variabile. Spatial variation seemed to occur within each site, but there was no common pattern among facilities. Substantial numbers of beetles were caught in the outdoor sticky flight traps for most locations, except for relatively low flight trap numbers at locations 1, 4 and 6. The results show that T. variabile and T. inclusum are commonly associated with DDGSs produced in the USA, that these beetles could infest product being shipped overseas, and provide information that can be used to develop risk assessment and pest management programs for the future.Dried distiller’s grains and solubles, DDGS, is a valuable commodity with substantial international trade. Vietnam discovered an infestation of Trogoderma inclusum, an actionable quarantine pest, in DDGS from the USA in 2012. All subsequent shipments to Vietnam were required to be fumigated. A shipment to Vietnam from the USA 2015 was then discovered with T. variabile. We surveyed the presence and activity of T. inclusum and T. variabile at locations in the USA that provide DDGSs for shipment to Vietnam. Seven facilities in four states that either produced DDGSs or that facilitated bulk shipments were studied. Pheromone traps were deployed at each location and monitored for several weeks. T. variaible was trapped at all seven sites while T. inclusum was trapped at just five of these. T. variabile were captured in nearly every trapping period and at higher numbers than T. inclusum at five locations, while two locations captured more T. inclusum than T. variabile. Spatial variation seemed to occur within each site, but there was no common pattern among facilities. Substantial numbers of beetles were caught in the outdoor sticky flight traps for most locations, except for relatively low flight trap numbers at locations 1, 4 and 6. The results show that T. variabile and T. inclusum are commonly associated with DDGSs produced in the USA, that these beetles could infest product being shipped overseas, and provide information that can be used to develop risk assessment and pest management programs for the future
Khapra beetle diagnostics: Poster
No full textThe khapra beetle, Trogoderma granarium Everts, is a serious pest of grains and stored dry food stuffs and is the subject of strict quarantine measures in many countries including Australia. Morphologically the khapra beetle can only be reliably identified by dissection by a limited number of skilled taxonomists. Suspect specimens found in grain products are usually the larvae or larval skins which are difficult to diagnose morphologically. Adult specimens are usually scarce and damaged. Due to their similarity, warehouse beetle (Trogoderma variabile) and other native Trogoderma spp. could be mistakenly identified as T. granarium with market access implicatons or could mask an incursion. Molecular diagnostic protocols have been developed for khapra beetle, but remain largely untested against other species of Trogoderma, some also capable of being pests. Western Australia has a broad large, poorly studied native Trogoderma fauna, many of which are still undescribed; their estimated number is possibly over 100 species. Occasionally native Australian species can occur in stored commodities. Their identification and at least separation from the pestiferous exotic Trogoderma presents a serious problem. The work in this paper has been undertaken in an attempt to distinguish T. granarium from Australian native Trogoderma and related Dermestid species by both morphological and molecular methods. Dermestid specimens were sourced mainly from a targeted survey around grain silos throughout Australia, using two trap types, inside and outside facilities. Khapra beetle specimens were sourced from different geographical locations around the world.The khapra beetle, Trogoderma granarium Everts, is a serious pest of grains and stored dry food stuffs and is the subject of strict quarantine measures in many countries including Australia. Morphologically the khapra beetle can only be reliably identified by dissection by a limited number of skilled taxonomists. Suspect specimens found in grain products are usually the larvae or larval skins which are difficult to diagnose morphologically. Adult specimens are usually scarce and damaged. Due to their similarity, warehouse beetle (Trogoderma variabile) and other native Trogoderma spp. could be mistakenly identified as T. granarium with market access implicatons or could mask an incursion. Molecular diagnostic protocols have been developed for khapra beetle, but remain largely untested against other species of Trogoderma, some also capable of being pests. Western Australia has a broad large, poorly studied native Trogoderma fauna, many of which are still undescribed; their estimated number is possibly over 100 species. Occasionally native Australian species can occur in stored commodities. Their identification and at least separation from the pestiferous exotic Trogoderma presents a serious problem. The work in this paper has been undertaken in an attempt to distinguish T. granarium from Australian native Trogoderma and related Dermestid species by both morphological and molecular methods. Dermestid specimens were sourced mainly from a targeted survey around grain silos throughout Australia, using two trap types, inside and outside facilities. Khapra beetle specimens were sourced from different geographical locations around the world
Controlling insects in stored grain by disturbing the grain: Presentation
No full textInsects can cause damage to stored grain, especially on smallholder farms in the tropics. Sitophilus zeamais (maize weevil, MW) and Rhyzopertha dominica (lesser grain borer, LGB) are often involved. Our objective was to determine, by four experiments, if physical disturbance of grain can control these pests. In Experiment 1, 2.6-L unsealed recycled coffee cans were each loaded with 1 kg of maize and 25 live adult MW/kg. Every 12 h, disturbed treatment cans were manually rolled through one circumference. After 160 d, live MW numbers had been reduced by 93% compared to undisturbed cans. In Experiment 2, MW-infested maize was placed in 20-L plastic cans and stored by farmers in Tanzania. Each farmer had three cans. Two were disturbed by shaking morning and evening and the third was left undisturbed. After 90 d, MW populations had increased in the undisturbed containers, but had decreased to zero in every disturbed container. In Experiments 3 (and 4), maize (wheat) infested with 25 adult MW/kg (LGB/kg) was placed in six boxes. Three of the boxes were disturbed every 12 h by use of Sukup motor-driven grain stirrers; the other three were undisturbed. After 120 days, MW numbers in undisturbed boxes had increased, but were zero in stirred boxes. In Experiment 4, 80-d samples showed increased numbers of LGB in undisturbed boxes but reductions of over 98% in stirred boxes. Quality of disturbed grain was similar or better than that of undisturbed grain. This work suggests that grain disturbance may be an effective non-chemical, non-hermetic physical approach for control of stored grain insects.Insects can cause damage to stored grain, especially on smallholder farms in the tropics. Sitophilus zeamais (maize weevil, MW) and Rhyzopertha dominica (lesser grain borer, LGB) are often involved. Our objective was to determine, by four experiments, if physical disturbance of grain can control these pests. In Experiment 1, 2.6-L unsealed recycled coffee cans were each loaded with 1 kg of maize and 25 live adult MW/kg. Every 12 h, disturbed treatment cans were manually rolled through one circumference. After 160 d, live MW numbers had been reduced by 93% compared to undisturbed cans. In Experiment 2, MW-infested maize was placed in 20-L plastic cans and stored by farmers in Tanzania. Each farmer had three cans. Two were disturbed by shaking morning and evening and the third was left undisturbed. After 90 d, MW populations had increased in the undisturbed containers, but had decreased to zero in every disturbed container. In Experiments 3 (and 4), maize (wheat) infested with 25 adult MW/kg (LGB/kg) was placed in six boxes. Three of the boxes were disturbed every 12 h by use of Sukup motor-driven grain stirrers; the other three were undisturbed. After 120 days, MW numbers in undisturbed boxes had increased, but were zero in stirred boxes. In Experiment 4, 80-d samples showed increased numbers of LGB in undisturbed boxes but reductions of over 98% in stirred boxes. Quality of disturbed grain was similar or better than that of undisturbed grain. This work suggests that grain disturbance may be an effective non-chemical, non-hermetic physical approach for control of stored grain insects
Numerical modeling of the horizontal flow and concentration distribution of nitrogen within a stored-paddy bulk in a large warehouse: Poster
Get PDFThe insect population in grain stores can be kept under control by maintaining a high concentration of N<sub>2</sub> gas throughout the grain bed. The development of controlled atmosphere storage technology for insect control requires an accurate prediction of the distribution of introduced gases in bulk grain. In this paper, based on the convective-diffusion model, the horizontal flow of N<sub>2</sub>, which was introduced into the paddy bulk in a large warehouse by means of the horizontal ventilation system, are modeled as fluid flow in a porous medium. The experimental data for N<sub>2</sub> transfer and flow through ducts and bulk paddy were used to validate the model. The equations were solved using the finite difference method, and the predictions from the proposed model were in good agreement with the experimental results. The concentration distribution and flow uniformity of nitrogen in stored paddy were also analyzed during the nitrogen-filling procedure for CA storage. It was shown that it is feasible and practical to introduce nitrogen into stored bulk grain in a large warehouse by means of the horizontal ventilation system.The insect population in grain stores can be kept under control by maintaining a high concentration of N<sub>2</sub> gas throughout the grain bed. The development of controlled atmosphere storage technology for insect control requires an accurate prediction of the distribution of introduced gases in bulk grain. In this paper, based on the convective-diffusion model, the horizontal flow of N<sub>2</sub>, which was introduced into the paddy bulk in a large warehouse by means of the horizontal ventilation system, are modeled as fluid flow in a porous medium. The experimental data for N<sub>2</sub> transfer and flow through ducts and bulk paddy were used to validate the model. The equations were solved using the finite difference method, and the predictions from the proposed model were in good agreement with the experimental results. The concentration distribution and flow uniformity of nitrogen in stored paddy were also analyzed during the nitrogen-filling procedure for CA storage. It was shown that it is feasible and practical to introduce nitrogen into stored bulk grain in a large warehouse by means of the horizontal ventilation system
Storage of mungbean in hermetic PVC tank: Presentation
No full textThis research was carried out to evaluate the effect of hermetic storage on quality of mungbean. About 260 kg of mungbean samples were stored in an especially design 350 L capacity hermetic PVC tanks (hermetic tank) and non-hermetic PVC tanks (control tank). Hermetic PVC tanks were closed air-tightly. All tanks were randomly placed in a warehouse. Each hermetic and control PVC tanks were artificially infested by 50 unsexed Callosobruchus chinensis kept in 4 glass jars containing 100 g of mungbean and jars were dipped in four different depths. The gas concentrations in the tanks were monitored up to 6 months intervals. Percentages of germination, moisture content, and grain damage were evaluated at the end of the storage. The oxygen content of hermetic samples was dropped to 11±1.2% and carbon dioxide content was increased up to 7±0.7% within 6 months of storage. Live insects of C. chinensis were not found in hermetic samples after 6 months but abundant population of C. chinensis was found in the control PVC tank just after one month. After 6 months, germination percentage of the mungbean samples stored in hermetic tanks had decreased from 95±3% to 82±4%, whereas it was decreased from 95±3% to 47±7% in control tanks due to grain damage. Percent grain damage of the hermetic sample was only 4.5±1% compared to the heavy insect damage of the control samples. Moisture content of hermetic samples remained unchanged compare to the control.This research was carried out to evaluate the effect of hermetic storage on quality of mungbean. About 260 kg of mungbean samples were stored in an especially design 350 L capacity hermetic PVC tanks (hermetic tank) and non-hermetic PVC tanks (control tank). Hermetic PVC tanks were closed air-tightly. All tanks were randomly placed in a warehouse. Each hermetic and control PVC tanks were artificially infested by 50 unsexed Callosobruchus chinensis kept in 4 glass jars containing 100 g of mungbean and jars were dipped in four different depths. The gas concentrations in the tanks were monitored up to 6 months intervals. Percentages of germination, moisture content, and grain damage were evaluated at the end of the storage. The oxygen content of hermetic samples was dropped to 11±1.2% and carbon dioxide content was increased up to 7±0.7% within 6 months of storage. Live insects of C. chinensis were not found in hermetic samples after 6 months but abundant population of C. chinensis was found in the control PVC tank just after one month. After 6 months, germination percentage of the mungbean samples stored in hermetic tanks had decreased from 95±3% to 82±4%, whereas it was decreased from 95±3% to 47±7% in control tanks due to grain damage. Percent grain damage of the hermetic sample was only 4.5±1% compared to the heavy insect damage of the control samples. Moisture content of hermetic samples remained unchanged compare to the control
The use of essential oils for the control of Callosobruchus subinnotatus (Pic) in stored Vigna subterranea L.: Presentation
No full textStudies were conducted in the Crop Science laboratory, University of Calabar to evaluate the insecticidal actions of essential oils (EOs) of Xylopia aethiopica, Dennetia tripetala, Pysostigma venenosum and Senna hirsuta in the management of Callosobruchus subinnotatus. The EOs were extracted using soxhlet apparatus with n-Hexane as the solvent. Four concentrations (0.25%, 0.50%, 1.00% and 2.00 %) and n-Hexane as control were laid out in completely randomized design with three replications. Parameters assessed included repellency, fumigant action, weight loss as well as Lethal concentration (LC50) of the treatments to the beetles at the lowest concentration of 0.25%. The EO of Senna hirsuta treated samples generally resulted in significantly (P > 0.05) lower weight loss than n-hexane treated samples. LC50 computation revealed that D. tripetala and P. venenosum (LC50 0.22 at 48 hrs) were most efficacious against C. subinnotatus. The result supports the use of the test plants by small scale farmers in the protection of stored V. substerranea against C. subinnStudies were conducted in the Crop Science laboratory, University of Calabar to evaluate the insecticidal actions of essential oils (EOs) of Xylopia aethiopica, Dennetia tripetala, Pysostigma venenosum and Senna hirsuta in the management of Callosobruchus subinnotatus. The EOs were extracted using soxhlet apparatus with n-Hexane as the solvent. Four concentrations (0.25%, 0.50%, 1.00% and 2.00 %) and n-Hexane as control were laid out in completely randomized design with three replications. Parameters assessed included repellency, fumigant action, weight loss as well as Lethal concentration (LC50) of the treatments to the beetles at the lowest concentration of 0.25%. The EO of Senna hirsuta treated samples generally resulted in significantly (P > 0.05) lower weight loss than n-hexane treated samples. LC50 computation revealed that D. tripetala and P. venenosum (LC50 0.22 at 48 hrs) were most efficacious against C. subinnotatus. The result supports the use of the test plants by small scale farmers in the protection of stored V. substerranea against C. subin
Lethal effects and mechanism of infrared radiation on Sitophilus zeamais and Tribolium castaneum in rough rice: Poster
Get PDFThe objective of this study was to investigate the characteristics of adult Sitophilus zeamais and Tribolium castaneum, and the 21.1% dry base (d.b.) MC of rough rice by ATR-FTIR spectra, and determine the theoretical optimum infrared (IR) heating temperature of the tested samples. In laboratory experiments, a ceramic IR drying device was used to heat infested rough rice to research the mortality of Sitophilus zeamais and Tribolium castaneum, the drying characteristics of rough rice, and milling quality. The theoretical calculation optimum temperature of IR heating was 300 °C according to the results of FTIR spectra. In addition, the effects of the different IR radiation intensities and heated rough rice temperatures on mortality of insects, moisture removal, and milling quality were determined in this text. A high insect mortality, heating rate and corresponding high moisture removal were achieved by using IR heating. After heating, tempering process significantly increased insect mortality when the heated tempered rice temperature was less than 55 °C, and improve moisture removal and milling quality of rough rice during nature air cooling. When the rice heated under the IR radiation intensity of 2780 W/m2 for 110 s, the rice temperature reached 60.2° ± 0.5°C, 100% mortality of S. zeamais and T. castaneum, and 3.97 percentage points of moisture removal during the heating period after tempering and natural cooling. In addition, the high rice milling quality can be achieved after tempering treatment. Therefore, it can be concluded that the optimum conditions of simultaneous disinfestation and drying were 60 °C rice temperature under the IR radiation intensity of 2780 W/m2, followed by tempering and natural cooling.The objective of this study was to investigate the characteristics of adult Sitophilus zeamais and Tribolium castaneum, and the 21.1% dry base (d.b.) MC of rough rice by ATR-FTIR spectra, and determine the theoretical optimum infrared (IR) heating temperature of the tested samples. In laboratory experiments, a ceramic IR drying device was used to heat infested rough rice to research the mortality of Sitophilus zeamais and Tribolium castaneum, the drying characteristics of rough rice, and milling quality. The theoretical calculation optimum temperature of IR heating was 300 °C according to the results of FTIR spectra. In addition, the effects of the different IR radiation intensities and heated rough rice temperatures on mortality of insects, moisture removal, and milling quality were determined in this text. A high insect mortality, heating rate and corresponding high moisture removal were achieved by using IR heating. After heating, tempering process significantly increased insect mortality when the heated tempered rice temperature was less than 55 °C, and improve moisture removal and milling quality of rough rice during nature air cooling. When the rice heated under the IR radiation intensity of 2780 W/m2 for 110 s, the rice temperature reached 60.2° ± 0.5°C, 100% mortality of S. zeamais and T. castaneum, and 3.97 percentage points of moisture removal during the heating period after tempering and natural cooling. In addition, the high rice milling quality can be achieved after tempering treatment. Therefore, it can be concluded that the optimum conditions of simultaneous disinfestation and drying were 60 °C rice temperature under the IR radiation intensity of 2780 W/m2, followed by tempering and natural cooling
