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A recent study showed the potential of the DA Perten 7200 NIR Spectrometer in detecting chlorpyrifos-methyl pesticide residue in rough, brown, and milled rice. However, this instrument is still lab-based and generally suited for point-of-sale testing. To provide a field-deployable version of this technique, an existing light emitting diode (LED)-based instrument that provides discrete NIR wavelength illumination and reflectance spectra over the range of 850–1550 nm was tested. Spectra were collected from rough, brown, and milled rice at different pesticide concentrations and analyzed for quantitative and qualitative measurement using partial least squares regression (PLS) and discriminant analysis (DA). Simulations for two LED-based instruments were also evaluated using corresponding segments of spectra from the DA7200 to represent LED illumination. For the simulation of the existing LED-based instrument (LEDPrototype1) fitted with 850, 910, 940, 970, 1070, 1200, 1300, 1450, and 1550 nm LED wavelengths, resulting R2 ranged from 0.52 to 0.71, and the correct classification was 70.4% to 100%. The simulation of a second LED instrument (LEDPrototype2) fitted with 980, 1050, 1200, 1300, 1450, 1550, 1600, and 1650 nm LED wavelengths showed R2 of 0.59 to 0.82 and correct classifications of 66% to 100%. These LED wavelengths were selected based on the significant wavelength regions from the PLS regression coefficients of DA7200 and the commercial availability of LED wavelengths. Results showed that it is possible to use a multi-spectral LED-based instrument to detect varying levels of chlorpyrifos-methyl pesticide residue in rough, brown, and milled rice.

Aerosol insecticides are widely used in stored product insect management programs in food facilities. Previous research has shown spatial variation in aerosol efficacy within facilities, but information on how spatial patterns of aerosol droplet concentration, size distribution, dispersal, and deposition contribute to this variation in efficacy is limited. This study involved two aerosol application systems: a high-pressure cylinder containing TurboCide Py-75® with pyriproxyfen IGR (ChemTech Ltd., Des Moines, IA, USA) and a hand-held fogger containing Pyrocide 100® (MGK, Minneapolis, MN, USA) with Diacon II which contains methoprene IGR (Wellmark, Schaumburg, IL, USA). These systems were used at single or multiple application locations. The spray trials were conducted in a small-scale flour mill, Hall Ross Flour Mill (Kansas State University, Manhattan, KS, USA). The droplet size distributions were monitored at multiple positions within the room using nine aerodynamic particle sizing (APS, TSI Incorp, Shoreview, MN, USA) instruments. The APS data collected over the treatment period were summarized into a mass concentration index (MCI), which ranged from 155 to 2549 mg/m3 for Turbocide and 235–5658 mg/m3 for Pyrocide. A second parameter called the Deposition Index (Dep.Idx) was derived to estimate potential insecticide depositions on the floor and has units of g/m2. The Dep.Idx was below 5.3 g/m2 for most Turbocide applications, while the Dep.Idx was below 8.4 g/m2 for most Pyrocide applications. The MCI and Dep.Idx values varied with APS position and spray application location, with proximity to the aerosol application location and degree of obstruction between the release point and APS position contributing to this variation. We assessed the relationship between aerosol droplet parameters and insect efficacy using Tribolium confusum Jacqueline DuVal, the confused flour beetle. The adults were treated directly, while the larvae were treated two weeks later during the residual test (previously published). For Turbocide, efficacy against adults increased with MCI and Dep.Idx values, but for residual efficacy of the IGR, efficacy was high at all aerosol droplet values, so no relationship was apparent. In contrast, the relationship between Pyrocide deposition and adult insect efficacy was highly variable. But with larval insect efficacy, residual larvae control was directly related to increases in Pyrocide MCI and Dep.Idx. Contour plots of Dep.Idx values were developed, which could be used to predict areas of the mill that are not receiving an adequate application rate, and this could be used to develop more effective application strategies for aerosol insecticides in food facilities.

Fumigation of grain bins with phosphine tablets is one method of insect control for stored products. Monitoring the concentration of the toxic gas at many locations over several days for a given structure or container can be challenging. In this study, a commercially-available system that wirelessly measures phosphine was evaluated in small-scale and large-scale tests. Small-scale testing was performed to study the repeatability and accuracy of the sensors. The wireless sensors were within 30 ppm of each other, over a range of 700 ppm phosphine. Large-scale testing evaluated the system during the fumigation of wheat stored in 7 m diameter, 120 metric ton, steel grain bins. As a reference, monitoring lines were distributed at several positions and depths in the bin in order to sample phosphine gas concentrations. A series of three fumigation trials were performed, with each lasting for over six days. The wireless devices collected local phosphine concentrations and temperatures every two hours without assistance from personnel. Although the fumigation trials were significantly different in terms of patterns in gas concentration over time, the two sampling methods gave similar trendlines. However, the automated data provided a more detailed picture of the fumigation process. This information may help fumigation managers to better evaluate fumigations and assure successful insect control.

In recent years, there has been an increasing interest and need for alternatives to structural fumigations, and one alternative that has been used across the industry is aerosol insecticides. Previous tests inside a pilot-scale mill demonstrated that aerosol particle size, delivery method, and the spatial configuration of the mill all influenced effectiveness. However, there is no research conducted inside large commercial facilities. The objective of this research was to evaluate a pyrethrin-plus-methoprene aerosol application inside a commercial mill on adult Tribolium confusum Jacquelin duVal, confused flour beetle, directly exposed to the aerosol and residual effects on larvae. Additionally, five aerodynamic particle sizer spectrometers were placed in the facility and recorded instantaneous spray concentration and estimated aerosol deposition. Adult T. confusum exposed nearest to the aerosol application points had the highest percentage of affected adults (>60%). The aerosol also had vertical movement when released at the top of a three-story open room; instantaneous concentrations were recorded on the ground floor. The aerosol residual was highly effective after 6-weeks post aerosol exposure, as 80% of the bioassays did not have any adult emergence from exposed larvae. This research demonstrates a practical use of aerosol insecticides and their potential to be an effective alternative to structural fumigations.

Historically, stored product insect pest management has been based around the use of methyl bromide and phosphine as fumigants. However, methyl bromide has been phased out for structural fumigations, and there is increasing worldwide insecticide resistance to phosphine. One potential alternative, environmentally friendly option is the use of methyl benzoate (MBe), which is considered a food safe compound. In this study, we evaluated the direct and sublethal effects of MBe exposure on the survivorship and mobility of four stored product species with diverse life histories, including Rhyzopertha dominica, Tribolium castaneum, Sitophilus zeamais, and Trogoderma variabile. Sets of insects were exposed to a control, low, or high MBe concentrations in flasks with or without food for 24 or 72 h in the laboratory. Furthermore, we assessed phosphine exposure under similar conditions. Overall, R. dominica was the most susceptible to MBe exposure, followed by T. castaneum. By contrast, S. zeamais and T. variabile were relatively unaffected by MBe exposure. Exposure to MBe induced multiple-fold decreases in the total distance moved and velocity of adults still considered alive or affected after assays. By comparison, phosphine effectively killed all individuals of all species. Our data suggest that while MBe was effective for R. dominica, it was not competitive in comparison to phosphine for controlling susceptible strains of these species at the specified experimental conditions.

The use of insects as animal feed has the potential to be a green revolution for animal agriculture as insects are a rich source of high-quality protein. Insect farming must overcome challenges such as product affordability and scalability before it can be widely incorporated as animal feed. An alternative is to harvest insect pests from the environment using mass trapping devices and use them as animal feed. For example, intensive agricultural environments generate large quantities of pestiferous insects and with the right harvest technologies, these insects can be used as a protein supplement in traditional animal daily rations. Most insect trapping devices are limited by the biomass they can collect. In that context, and with the goal of using wild collected insects as animal feed, the United States Department of Agriculture-Biomass Harvest Trap (USDA-BHT) was designed and built. The USDA-BHT is a valuable mass trapping device developed to efficiently attract, harvest, and store flying insects from naturally abundant agricultural settings. The trap offers a modular design with adjustable capabilities, and it is an inexpensive device that can easily be built with commonly available parts and tools. The USDA-BHT is also user-friendly and has customizable attractants to target various pest species.

The demand for animal protein grows as the human population increases. Technological and genetic advances in traditional animal agriculture will not produce enough protein to meet future needs without significant innovations such as the use of insects as protein sources. Insect farming is growing insects, whereas insect harvesting is collecting insects from their natural habitats to produce high-quality protein for animal feed or human food. Intensive agricultural environments produce tremendous quantities of pestiferous insects and with the right harvest technologies these insects can be used as a protein supplement in traditional animal daily rations. An avenue to exploit these insects is to use traps such as the United States Department of Agriculture-Biomass Harvest Trap (USDA-BHT) to efficiently attract, harvest, and store insects from naturally abundant agricultural settings. The modular design allows for a low cost, easy to build and fix device that is user friendly and has customizable attractants to target various pest species. Although insect harvesting faces substantial challenges, including insect biomass quantity, seasonal abundance and preservation, food safety, and economic and nutritional evaluation, the potential for utilizing these pests for protein shows tremendous promise. In this forum, insect harvesting is discussed, including its potential, limitations, challenges, and research needs. In addition, the use of a mass trapping device is discussed as a tool to increase the biomass of insects collected from the environment.

Background/Objectives: Phosphine resistance in insects involves a complex interplay of genetic and physiological factors, which are often poorly understood. Resistance to high concentrations of phosphine worldwide poses a formidable challenge for stored-product pest management and affects global food security. Understanding the genetic basis of phosphine resistance in the red flour beetle, Tribolium castaneum, is urgent because of the species’ status as a notorious insect pest of stored grains and their resistance to major classes of insecticides. In this study, we take advantage of T. castaneum as a model species for biological and genetic studies. Methods: To tease apart genetic mutations and the differential expression of genes responding to phosphine intoxication, we set up 16 different exposure tests to compare the effects of phosphine dose, exposure time, and sampling time on gene expression in phosphine-susceptible and -resistant T. castaneum adults. Results: We examined the enrichment of gene ontology terms in genes that were differentially expressed and found that the data further distinguished differences in gene expression by insect strain, phosphine dose, exposure time, and recovery from phosphine exposure. The gene-encoding cytochrome P450 9e2 was expressed more in phosphine-resistant compared to phosphine-susceptible insects under all treatment conditions and was significantly higher in expression in resistant insects that were sampled after short or long phosphine exposures. Therefore, this gene may serve as a new phosphine resistance marker in T. castaneum and can further be utilized as a diagnostic tool for resistance detection. Conclusions: These data are important to understand the complex molecular changes in insects that have reduced sensitivity to phosphine to develop new monitoring and resistance prevention strategies.

Studies have investigated the potential of using farmed insects in animal feeds; however, little research has been done using wild-caught insects for this purpose. Concerns about inadequate quantities collected, environmental impacts, and the spread of pathogens contribute to the preferred utilization of farmed insects. Nevertheless, by harvesting certain pest species from intensified agricultural operations, producers could provide their animals with affordable and sustainable protein sources while also reducing pest populations. This study explores the possibility of collecting large quantities of pest flies from livestock operations and analyzes the flies' nutritional content, potential pathogen load, and various disinfection methods. Using a newly designed mass collection-trapping device, we collected 5 kg of biomass over 13 wk, primarily house flies, from a poultry facility. While a substantial number of pests were removed from the environment, there was no reduction in the fly population. Short-read sequencing was used to compare the bacterial communities carried by flies from differing source populations, and the bacterial species present in the fly samples varied based on farm type and collection time. Drying and milling the wild-caught flies as well as applying an additional heat treatment significantly reduced the number of culturable bacteria present in or on the flies, though their pathogenicity remains unknown. Importantly, these disinfection methods did not affect the nutritional value of the processed flies. Further research is necessary to fully assess the safety and viability of integrating wild-caught insects into livestock feed; however, these data show promising results in favor of such a system.

Insects are a promising source of high-quality protein, and the insect farming industry will lead to higher sustainability when it overcomes scaling up, cost effectiveness, and automation. In contrast to insect farming (raising and breeding insects as livestock), wild insect harvesting (collecting agricultural insect pests), may constitute a simple sustainable animal protein supplementation strategy. For wild harvest to be successful sufficient insect biomass needs to be collected while simultaneously avoiding the collection of nontarget insects. We assessed the performance of the USDA Biomass HarvestTrap (USDA-BHT) device to collect flying insect biomass and as a mosquito surveillance tool. The USDA-BHT device was compared to other suction traps commonly used for mosquito surveillance (Centers for Disease Control and Prevention (CDC) light traps, Encephalitis virus surveillance traps, and Biogents Sentinel traps). The insect biomass harvested in the USDA-BHT was statistically higher than the one harvested in the other traps, however the mosquito collections between traps were not statistically significantly different. The USDA-BHT collected some beneficial insects, although it was observed that their collection was minimized at night. These findings coupled with the fact that sorting time to separate the mosquitoes from the other collected insects was significantly longer for the USDA-BHT, indicate that the use of this device for insect biomass collection conflicts with its use as an efficient mosquito surveillance tool. Nevertheless, the device efficiently collected insect biomass, and thus can be used to generate an alternative protein source for animal feed.