Studies were conducted by exposing different life stages of Tribolium castaneum (Herbst), the red flour beetle, and Trogoderma inclusum (Leconte), the larger cabinet beetle, for different time intervals to -18 degrees C. Assessments were made of direct mortality to eggs, larvae, and adults, and eventual adult emergence of immatures. Data were described by non-linear equations. The eggs and larvae were the most tolerant life stage of T. castaneum. Eight hours of exposure were required for 100% kill of 3-4-day-old eggs and 0-10- and 11-21-day-old larvae, but only 4, 0.5, and 0.5 h respectively were required to completely inhibit adult emergence. For T. inclusum, the most tolerant life stage was 15-28-day-old larvae; 64 and 16 h respectively were required for complete mortality and inhibition of adult emergence. Results indicate that T. inclusum was the more tolerant species, and specific treatment protocols may be required for different stored product beetle species when using -18 degrees C as a disinfestation strategy. (C) 2015 Published by Elsevier Ltd.

We conducted studies using a commercial freezer maintained at -17.8 degrees C to determine the time needed to kill Tribolium castaneum eggs in a pallet of flour. Each bag weighed 22.7 kg, and there were 5 bags in each of 10 layers. The dimensions of the pallet were 109-cm wide by 132-cm long by 123-cm tall, and the weight of the stacked pallet was approximately 1152 kg. We conducted tests for nine internal goal temperatures of -12, -10, -8, -6, -4, -2, 0, 4 and 8 degrees C. Internal temperatures in the most central location of the flour pallet reached: -11.0, -9.4, -6.9, -5.0, -3.5, -1.6, -0.1, 3.3, and 5.6 degrees C and were achieved after 11.0, 9.1, 8.9, 7.2, 6.7, 5.8, 5.5, 5.2, and 4.2 days, respectively. For treatments where the goal temperature for the center bag ranged from -12 to 4 degrees C, egg mortality was 100% in bags located in both the periphery and in the center of the pallet. When the temperature goal for the center bag was 8 degrees C, 7 +/- 2.5% of the eggs survived in bags located near the center of the pallet. Our data showed that temperatures that follow the dynamic temperature curve that takes place over 24.2 days (cool down and warm up for the 0 degrees C temperature goal) resulted in 100% mortality of T. castaneum eggs. The reason for the difference in mortality for a static compared to a dynamic temperature treatment may be due to the fact that the dynamic temperature treatment occurs over a much longer duration. The fact that the treatment only required 5.5 days in the freezer before it could be shipped makes it a practical method to disinfest pallets of flour, especially because the bags do not need to be removed from the pallet and no chemicals are used. Published by Elsevier Ltd.

ABSTRACTA simple, rapid method that uses a small mechanical rotary device (entoleter) was developed for estimating insect fragment counts in flour caused by hidden, internal‐feeding insects in whole grains of hard red winter and soft red winter wheat. Known counts of preemergent adults, pupae, and larvae of lesser grain borers and rice weevils were blended with 500 g samples of uninfested wheat. The entoleter impeller speed was adjusted based on grain hardness and moisture content to obtain about ≈98% intact and ≈2–2.5% broken kernels in an uninfested sample. The entoleter flung the wheat kernels against a surrounding steel ring. Approximately 70–90% of the insect‐infested kernels, being weaker, released internal insect pieces upon impact. The broken kernels were sieved with number 10 and number 20 sieves to obtain large‐sieved and small‐sieved fractions, respectively. Insect pieces in sieved fractions were counted. The insect piece counts were correlated with the estimated flour fragments (R2 = 0.94). The entoleter method can distinguish samples of grain containing 0, 25, or 75 fragments in 50 g of flour, with greater than 95% confidence. The method can be performed in approximately 5 min per 500 g sample and could potentially be a cost‐effective method that grain handlers can use to inspect wheat loads for detecting insect damage and estimating insect fragments in flour.

Stored-product entomologists have a variety of new monitoring, decision-making, biological, chemical, and physical pest management tools available to them. Two types of stored-product insect populations are of interest: insects of immediate economic importance infesting commodities, and insects that live in food residues in equipment and facilities. The sampling and control methods change as grain and grain products move from field to consumer. There are also some changes in the major insect pest species to take into consideration. In this review, we list the primary insect pests at each point of the marketing system, and indicate which sampling methods and control strategies are most appropriate. Economic thresholds for insect infestation levels developed for raw commodity storage, processing plants, and retail business allow sampling-based pest management to be done before insect infestations cause economic injury. Taking enough samples to have a representative sample (20-30 samples) will generally provide enough information to classify a population as above or below an economic threshold.

Modifications were made to a small laboratory mill to enable the detection of rice kernels internally infested by immature grain insects. The mill, which was originally designed for wheat, monitors electrical conductance through the grain and detects kernels that are infested with live insects based on abrupt changes in electrical conductance as the insects inside the kernels are crushed between the mill rolls. The mill was adapted to detect rice infested by immature lesser grain borers (LGB) by altering the gearing and reducing the gap between the two mill rolls to produce shear between the rolls. Samples of LGB infested long, medium, and short grain (dehulled) brown rice and hard red winter wheat were tested in both the modified and original mills. The detection rates for long grain brown rice kernels infested with large, medium, and small LGB larvae were 97, 83, and 42%, respectively, with the modified mill and 61, 22, and 4%, respectively, with the original mill. Similar detection rates were observed ...

Data were collected in 1998–2002 from wheat stored in commercial grain elevators in south-central Kansas. Bins at these elevators had concrete walls and were typically 6–9m in diameter and 30–35m tall. A vacuum-probe sampler was used to collect grain samples in the top 12m of the wheat in each bin. The primary insect species found in the wheat samples were: Cryptolestes ferrugineus, Rhyzopertha dominica, and Tribolium castaneum. In the top 3.7m of grain, R. dominica, C. ferrugineus, T. castaneum and Sitophilus oryzae made up 44, 36, 19 and 1% of the insects found in the samples, respectively. From 3.8 to 12.2m, R. dominica, C. ferrugineus, T. castaneum and S. oryzae were present at 84, 8, 8, and 1%, respectively. The most prevalent species also changed over time. In June, the start of wheat harvesting and storage in Kansas, insect density was low in the bins. At this time, C. ferrugineus was the most common insect, and it was found mostly in the top grain sample (0–1.2m). In September through November, C. ferrugineus and R. dominica were at similar densities; however, from February to March, R. dominica was more common.

Integrated pest management (IPM) in stored wheat could increase worker safety, reduce environmental concerns, and may reduce the chances of loss in grain quality. Managers of many country elevators, however, continue to use chemical-based approaches. To determine if this choice is economically justified, total costs (including both costs of implementation and costs of failing to control insects) for sampling-based IPM and calendar-based chemical approaches were simulated and compared for country elevators operating under typical conditions in the Central and Southern Plains of the United States.

Susceptibility of Lasioderma serricorne (F.) (Coleoptera: Anobiidae) Life Stages to Elevated Temperatures Used During Structural Heat Treatments Authors: C. Yu, B. Subramanyam, P.W. Flinn, J.A. Gwirtz Submitted to: Journal of Economic Entomology Methyl bromide is still widely used in food processing and storage facilities for the suppression of storedproduct insect pests, but its use is scheduled to be phased out as part of the Montreal Protocol. Little information is available on the response of the cigarette beetle, Lasioderma serricorne (F.), a pest associated with food-processing facilities, to elevated temperatures. Heat treatment of food-processing facilities involves using elevated temperatures (46 to 60°C for 24 h) for management of stored-product insect pests. In collaboration with scientists at Kansas State University, we evaluated stage-specific susceptibility of L. serricorne to elevated temperatures in order to identify the most heat tolerant stage. Exposure of eggs, larvae, pupae, and adults to 46, 50 and 54°C, in the laboratory indicated the egg stage to be the most heat-tolerant. The lethal time to kill 99% of eggs at 46°C was 605 min; it decreased to 190 min at 50°C, and 39 min at 54°C. Therefore, during structural heat treatments, eggs should be used in bioassays for gauging the effectiveness of heat treatments, because treatments aimed at controlling the egg stage should control all other life stages of L. serricorne. Contact Paul Flinn, telephone 785-776-2707, email paul.flinn@ars.usda.gov

We studied the temporospatial distribution of psocids in steel bins containing 32.6 tonnes of wheat in 2005 and 2006 in Manhattan, KS. Psocids were sampled in the top 0.9 m of wheat using a 1.2-m open-ended trier; samples were taken from the bin center and in the four cardinal directions at 0.15 and 0.76 m from the bin wall. In addition, a 2.4-m partitioned grain trier with 16 compartments was used to sample psocids from a 2-m-diameter circle in the center of the bins and to a depth of 1.96 m. Only two species of psocids were identified in the study: Liposcelis entomophila in 2005 and L. decolor in 2006. Densities of psocids were low immediately after bins were filled in July 2005, peaked in October, dropped to almost zero in December as temperatures decreased, and remained at low levels until the study was ended in March. In 2006, densities of psocids increased gradually from August to mid-October and declined until the study was ended in early November. During the fall, psocids were more abundant at the center of the bin and at lower depths. In October to November of both years, the temperatures and moisture contents of grain in the center also were higher than that in other locations. This is the first report of temporospatial distribution of psocids in steel bins of wheat.

Psocids are an emerging problem in grain storage, handling, and processing facilities in the United States. We used data from two steel bins each containing 32.6 metric tonnes of wheat, Triticum aestivum L., to develop sampling plans for Liposcelis entomophila (Enderlein), Liposcelis decolor (Pearman) (both Psocoptera: Liposcelididae), and a mixture of the two species. Taylor's coefficients a (a sampling factor) and b (an index of aggregation) for these pests were calculated and incorporated into sampling protocols to improve accuracy. The optimal binomial sample sizes for estimating populations of these psocids at densities of <25 psocids per refuge were large; therefore, we recommend the use of numerical sampling within this range of densities. Numerical sampling of L. entomophila and L. decolor at densities of <25 psocids per refuge should not be too laborious given the low psocid numbers involved; we recommend using 10 refuges per bin. For presence-absence sampling of L. entomophila or L. decolor, 20 refuges per bin should be used at densities of 25-100 psocids per refuge. The sampling plans we have developed based on the use of cardboard refuges are convenient for use in steel bins containing wheat because they are inexpensive, provide a rapid assessment of psocid population incidence, and are easy to implement. These sampling plans can be used to monitor populations of and the efficacy of management strategies used against L. entomophila and L. decolor.

An evaluation of five sampling methods for studying psocid population levels was conducted in two steel bins containing 32.6 tonnes of wheat in Manhattan, KS. Psocids were sampled using a 1.2-m open-ended trier, corrugated cardboard refuges placed on the underside of the bin hatch or the surface of the grain, and manual or automated electronic counts from Insector probe traps. Only two species were identified in this study: Liposcelis entomophila (Enderlein) in 2005 and L. decolor (Pearman) in 2006. In both years, psocid numbers started to increase in early September, peaked earliest in surface refuges, and peaked at nearly the same time in grain samples and manual and electronic Insector counts. No psocids were found in hatch refuges in December to February, although psocids were detected by the other sampling methods during this time. Numbers of psocids in the grain samples could be estimated from the numbers of psocids obtained using the cardboard refuges and Insector probe traps in both years. The results indicate that cardboard refuges or Insectors may provide an effective method for sampling psocids in bins of wheat.

Manual sampling of insects in stored grain is a laborious and time-consuming process. Automation of grain sampling should help to increase the adoption of stored grain integrated pest management. A new commercial electronic grain probe trap (OPI Insector) has recently been marketed. We field tested OPI Insector electronicgrain probes in two bins, each containing 32.6 tonnes of wheat, Triticum aestivum L., over a 2-yr period. We developed new statistical models to convert Insector catch into insects per kilogram. We compared grain sample estimates of insect density (insects per kilogram of wheat) taken near each Insector to the model-predicted insect density by using Insector counts. An existing expert system, Stored Grain Advisor Pro, was modified to automatically read the Insector database and use the appropriate model to estimate Cryptolestes ferrugineus (Stephens), Rhyzopertha dominica (F.), and Tribolium castaneum (Herbst) density from trap catch counts. Management decisions using Insector trap-catch estimates for insect density were similar to those made using grain sample estimates of insect density for most sampling dates. However, because of the similarity in size of R. dominica and T. castaneum, the software was unable to differentiate counts between these two species. In the central and southern portions of the United States, where both species frequently occur, it may be necessary to determine the proportion of each species present in the grain by manual inspection of trap catch. The combination of SGA Pro with the OPI Insector system should prove to be a useful tool for automatic monitoring of insect pests in stored grain.

The use of chemical pesticides to control stored product insects can be reduced with Integrated Pest Management (IPM) practices such as the use of natural enemies, like parasitoids, to control harmful insects. In this study, improved specifications were developed for shipping containers to deliver healthy beneficial insects to IPM practitioners. Heat transfer through the container walls was evaluated to determine the amount of insulation and natural refrigerant (such as ice) necessary for maintaining the internal temperature in the desirable range throughout the shipping time and was based on recommended temperature limits for commercial shipments. An energy balance on the shipping containers was used to provide the needed design equation to specify the insulation level. Data were obtained from containers with temperature-monitoring sensors when shipped by overnight express from a cooperating supplier's laboratory to GMPRC. Also, standard frozen gels and other potential natural refrigerants were compared in laboratory tests of the containers at times and temperatures comparable to those measured in the experimental shipments. The 0.6% water in dioxane mixture had the best results of the solvents evaluated as refrigerants.

Hard red winter wheat kernels were infested with eggs of Rhyzopertha dominica . After 20 d, when the larvae reached the fourth instar, they were killed by exposing the infested kernels to phosphine gas for 24 h. The infested kernels were then divided into four portions and treated as follows: one portion was immediately frozen at −80 °C to avoid myosin degradation; the other three portions were kept at 32 °C and 65% relative humidity, and then frozen at −80 °C after 14, 28, and 56 d post-fumigation, respectively. Each treatment was replicated five times. Myosin was measured using a commercial enzyme linked immunosorbent assay (ELISA) method that specifically detects this protein (Biotect ® , Austin, TX). Myosin degradation was most rapid in the first 2 weeks after the larvae were killed, decreasing from 1.672 to 0.695 ng/well during this period (a 58.4% reduction). There were no significant differences in myosin degradation between samples that were 14, 28, and 56 d post-fumigation. Grain is often fumigated to control insects. Frequently, this occurs many weeks before the grain is milled and may be repeated during the storage period. Therefore, estimates using the ELISA test may underestimate internal insect infestation because of myosin degradation. Insect fragment estimates for previously fumigated grain could be underestimated by as much as 58%.

The United States Department of Agriculture's Agricultural Research Service (USDAARS) funded a demonstration project between 1998 and 2003 for area-wide integrated pest management (AW-IPM) of commercial stored wheat in Kansas and Oklahoma. The AW-IPM concept is useful to stored grain because it reduces the mixing of infested and uninfested grain at the terminal elevator by controlling insect problems in small country elevators before the grain is shipped to the terminal elevator. This project was a collaboration of the USDA-ARS Grain Marketing and Production Research Center in Manhattan, Kansas, Kansas State University, and Oklahoma State University. The project utilized two elevator networks, one in each state. Over the five years of the study, researchers worked in approximately 55 country elevators and four terminal elevators, and collected and analysed more than 125 000 grain samples. Wheat at elevators was frequently infested by several insect species, which sometimes reached high numbers and damaged the grain. Fumigation using aluminum phosphide is the main method for controlling insect pests in grain elevators in the USA. Fumigation decisions tended to be based on past experience with controlling stored-grain insects, or were calendar-based. The best sampling method for estimating insect density in commercial elevators without having to transfer the grain from bin to bin was the vacuum probe sampler. Decision-support software "Stored Grain Advisor Pro (SGA Pro)" was developed that interprets insect sampling data and provides grain managers with a risk analysis report for their elevator that specifies the current and predicted risk for each bin. Recommended treatment strategies and economic analysis were presented to the elevator managers at six-week intervals. Elevators that followed the recommendations reduced the number of bins they normally fumigated by at least 50%. The AW-IPM programme was superior to calendar-based management because it ensured that the grain in each bin was only treated when insect densities exceeded economic thresholds. This approach reduced the frequency of fumigation while maintaining high grain quality. Minimizing the use of fumigant improves worker safety and reduces control costs and harm to the environment. A grain-scouting company was started that uses SGA Pro and the sampling tools that were developed in this project. The company is in its third year and has over 30 commercial elevators on contract.

A decision support system, Stored Grain Advisor Pro (SGA Pro) was developed to provide insect pest management information for wheat stored at commercial elevators. The program uses a model to predict future risk based on current insect density, grain temperature and moisture. A rule-based system was used to provide advice and recommendations to grain managers. The software was tested in a research program conducted at commercial grain elevators in Kansas and Oklahoma, USA. A vacuum-probe sampler was used to take ten 3-kg grain samples in the top 12 m of each bin that contained wheat. After the insect species and numbers were determined for each sample, the data were entered into SGA Pro. A risk analysis and treatment recommendation report for all bins was presented to the grain managers every 6 weeks. SGA Pro correctly predicted for 71–80% of bins whether the grain was safe or at high risk of dense infestation and grain damage. SGA Pro failed to predict "unsafe" insect densities in only 2 out of 399 Kansas bins (0.5%) and in none of 114 bins in Oklahoma. Grain managers who followed SGA Pro's recommendations tended to fumigate only the bins with high insect densities instead of fumigating all bins at their facility. This resulted in more efficient insect pest management because fumigating bins only when insect densities exceeded economic thresholds and treating only the bins that required fumigation minimized the risk of economic losses from insects, reduced the cost of pest management, and reduced the use of grain fumigant.

The hymenopteran parasitoid, Theocolax elegans (Westwood), and transgenic avidin maize powder were tested to determine if their individual or combined use would protect stored grain from infestation by both internal and external insect pests. Small-scale tests were conducted in plastic jars containing 3kg of non-transgenic maize. We tested treatments of 0.3% powdered avidin maize, the parasitoid wasp, and the combination of the parasitoid plus 0.3% powdered avidin maize. One pair each of Sitophilus zeamais Motschulsky, Tribolium castaneum (Herbst), and Cryptolestes ferrugineus (Stephens) was added to each jar. After 8 weeks, the entire contents of each jar were examined for adult insects. Control and avidin maize powders had no detrimental effects on the beneficial insect parasitoid T. elegans. The parasitoid suppressed populations of the internal feeder S. zeamais. The avidin maize powder treatment had no effect on S. zeamais because these larvae developed inside the maize kernels where no avidin maize powder was present. For S. zeamais, the combination treatment was not significantly different from the parasitoid treatment. In contrast, populations of the external feeder T. castaneum were not suppressed by the parasitoid but were suppressed by the avidin maize powder treatment. The parasitoid-avidin combination treatment produced the greatest percentage reduction for all three insect species and resulted in 78%, 94%, and 70% reductions in populations of S. zeamais, T. castaneum, and C. ferrugineus, respectively, when compared to the control treatment. The percentage reductions for the parasitoid treatment were 70%, 8%, and 20% for S. zeamais, T. castaneum, and C. ferrugineus, respectively. For the avidin maize powder treatment, populations of S. zeamais, T. castaneum, and C. ferrugineus were reduced by 10%, 85%, and 40%, respectively. The combination treatment of avidin maize powder plus the release of parasitoid wasps was superior to either treatment alone when applied to mixed populations of internal and external feeders.