AI ‐Based Image Profiling and Detection for the Beetle Byte Quintet Using Vision Transformer ( ViT ) in Advanced Stored Product Infestation Monitoring

Metals in mandibles of stored product insects: do zinc and manganese enhance the ability of larvae to infest seeds?

Studies on the use of light traps for attracting stored product insects were conducted in a rice mill and in paddy seed stores. In these stores the light traps were placed near the products. Light traps with 6 W blacklight-blue alone could effectively attract Angoumois grain moth (Sitotroga cerealella), lesser grain borer (Rhyzopertha dominica), maize weevil (Sitophilus zeamais) and red flour beetle (Tribolium castaneum). When the light traps with blacklight-blue, fluorescent lamps, green colour incandescent lamps, and blacklight lamps were operated simultaneously in a store containing paddy seeds, there was no significant difference between these three kinds of light in attracting maize weevil, but Angoumois grain moth was attracted more to blacklight-blue and blacklight than to the green incandescent lamp. The lesser grain borer preferred the blacklight to the blacklight-blue and the green incandescent lamps. In the experiments, only adult insects were caught in the traps.

Identification of insect-damaged wheat kernels using short-wave near-infrared hyperspectral and digital colour imaging

Spinosad is a bacterial fermentation product that has low mammalian toxicity. It exhibits both stomach and contact activities against insects. Spinosad is commercially registered on 250 crops in more than 24 countries. It is not registered for use on stored grains. Laboratory and field tests on wheat and maize have shown that this product is effective against the lesser grain borer (Rhyzopertha dominica), rice weevil (Sitophilus oryzae), flat grain beetle (Cryptolestes pusillus), rusty grain beetle (Cryptolestes ferrugineus), confused flour beetle (Tribolium confusum) and larvae of the Indian meal moth (Plodia interpunctella) at 1 mg/kg. On stored grain, adults of the red flour beetle (T. castaneum) and saw-toothed grain beetle (Oryzaephilus surinamensis) are less susceptible to spinosad than other species. In farm bins, spinosad on wheat at 0.1-6 mg/kg was stable for one year. This was confirmed by residue data and bioassays against the lesser grain borer and red flour beetle. The trend in species susceptibility was consistent among grain types (maize and wheat), but varied among wheat classes. On concrete, steel, floor tile and waxed floor tile surfaces, spinosad provided >98% mortality of adults of eight stored product beetles exposed for 24 h to deposits of 0.05 and 0.1 mg/cm2. Activity against a variety of stored product insects, persistence in farm-stored grain, and low mammalian toxicity make spinosad a viable alternative to currently registered organophosphate grain protectants, such as malathion, chlorpyrifos-methyl and pirimiphos-methyl.

Monitoring is fundamental to integrated pest management programs since it provides feedback on effectiveness of prevention programs and helps with targeting interventions as needed and evaluating their effectiveness. Rice mills are spatially complex facilities that have a combination of rough rice storage bins, buildings where rice is milled and processed, and warehouses and bulk storage bins where finished product is held before shipment. Each of these structures can have its own suite of insect species, different levels of risk, as well as different suites of management tools available. At a large rice mill in Brazil, stored product insect activity was monitored using food bait traps placed around rough rice receiving areas and storage bins; inside building containing white rice mill, rice flour mill, and packaging; and inside building for processing parboiled rice. The facility was monitored from 2010 to 2018 with 100 traps. Major pest species recovered at the facility included Sitophilus oryzae, Sitophilus zeamais, Rhyzopertha dominica, Tribolium castaneum, Cryptolestes ferrugineus, Ahasverus advena, Oryzaephilus surinamensis, Typhaea stercorea, Anthicus floralis, and Nitidulidae species. Temporal and spatial patterns in abundance were evaluated for each of the major species and for major functional groups (primary feeders, secondary feeders, and fungal feeders). Monitoring data generated was used to guide pest management programs and also provided the information needed to develop management thresholds.

Insect populations in 14 bins of newly harvested wheat on eight farms in Kansas were monitored with sticky traps in the bin headspace and with grain samples. Sticky trap catches during the first 3 wk of storage were used to provide an estimate of the species and densities of insects that were present in the headspace. Grain samples were taken every 2 wk during the first 3 mo of storage to provide an estimate of population growth under the grain temperature and moisture conditions in the bins. The sticky traps correctly predicted whether lesser grain borer, Rhyzopertha dominica (F.), and rusty grain beetle, Cryptolestes ferrugineus (Stephens), would be found in the grain samples in 85.8 and 78.6% of the bins, respectively. Traps were less reliable for foreign grain beetle, Ahasverus advena (Waltl), and hairy fungus beetle, Typhaea stercorea (L.), with correct predictions in 57.1 and 42.9% of bins, respectively. Indianmeal moth, Plodia interpunctella (Hubner), was found in both traps and grain samples in only one bin and red flour beetle, Tribolium castaneum (Herbst), and sawtoothed grain beetle, Oryzaephilus surinamensis (L.), were not found in both traps and grain samples in any of the bins. The traps in the center of the bin caught 4.7–14.2 times more beetles than those on the bin walls, but only 1.3 times more P. interpunctella adults. The total numbers of C. ferrugineus adults in the grain samples could be predicted better from the product of mean grain temperature times maximum grain moisture than from sticky trap catch.

A no-choice test was performed to determine survival and reproductive capacity of stored-product insect pests on pecan, Carya illinoensis (Wangenheim) Koch. Insects used were Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae); sawtoothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Cucujidae); red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae); lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae); and rusty grain beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae). Fifty adults of each beetle species or 10 reproductive pairs of P. interpunctella adults were placed in 0.5-liter containers with either whole-shell pecans, cracked-shell pecans, randomly selected in-shell pecans, pecan nutmeats, cracked wheat, or glass beads and held at 28 degrees C, 60-70% relative humidity, and 16:8 (L:D) photoperiod for 2, 4, 6, and 8 wk. Four replications of each insect-diet-interval combination were performed. Larvae of P. interpunctella, O. surinamensis, T. castaneum, C. ferrugineus, and adult P. interpunctella and O. surinamensis developed on cracked and nutmeat pecan diets. R. dominica did not complete reproduction on pecans. Knowledge that these pests can reproduce on stored pecan will assist pecan growers, accumulators, and storage facilities in preventing insect outbreaks on their product.

Hemp (Cannabis sativa) seed for reproduction of stored-product insects

In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored‐grain insects have been published. In this paper, we evaluated the efficacy of spinosad against seven major stored‐grain insects on shelled corn in the laboratory. Insect species tested were the red flour beetle, Tribolium castaneum (Jacquelin duVal); rusty grain beetle, Cryptolestesferrugineus (Stephens); lesser grain borer, Rhyzopertha dominica (F.); sawtoothed grain beetle, Oryzaephilus surinamensis (L.); rice weevil, Sitophilus oryzae (L.); maize weevil, Sitophilus zeamais (Motschulsky); and Indian meal moth, Plodia interpunctella (Hübner). Corn kernels were treated with spinosad at 0, 0.1, 0.5, 1, and 2 active ingredient (a.i.) mg/kg for controlling the seven species. Beetle adults or P. interpunctella eggs were introduced into each container holding 100 g of untreated or insecticide‐treated corn. The seven insect species survived well on the control treatment, produced 28 to 336 progeny, and caused significant kernel damage after 49 days. On spinosad‐treated corn, adult mortality of C. ferrugineus, R. dominica, O. surinamensis, S. oryzae, and S. zeamais was > 98% at 1 and 2 mg/kg after 12 days. Spinosad at > 0.5 mg/kg completely suppressed egg‐to‐larval survival after 21 days and egg‐to‐adult emergence of P. interpunctella after 49 days, whereas 16%T. castaneum adults survived at 1 mg/kg after 12 days. Spinosad at 1 or 2 mg/kg provided complete or near complete suppression of progeny production and kernel damage of all species after 49 days. Our results indicate that spinosad at the current labeled rate of 1 mg/kg is effective against the seven stored‐grain insect pests on corn.

Detailed information on insect pests of stored grains in Nigeria is lacking. A two-year survey was conducted to determine the species composition and abundance of insects associated with maize, millet, rice, sorghum and tamarind in eighteen locations across five agro-ecological zones in Nigeria. Sixteen coleopteran, lepidopteran and hymenopteran species were associated with stored products, with high species richness on cereal grains but low species richness on tamarind. Most of these insects are polyphagous on cereal grains, whereas the tamarind weevil Sitophilus linearis (Herbst, 1797) (Curculionidae), and Caryedon serratus (Oliver, 1790) (Chrysomelidae) were found only on tamarind in this study. The maize weevil Sitophilus zeamais (Motschulsky, 1758), rice weevil Sitophilus oryzae (Linneaus, 1763), lesser grain borer Rhyzopertha dominica (Fabricius, 1792) (Bostrichidae), rusty grain beetle Cryptolestes ferrugineus (Stephens, 1831) (Laemophloeidae) and red flour beetle Tribolium castaneum (Herbst, 1797) (Tenebrionidae) were most abundant on stored grains. The tamarind weevil, C. serratus and the sawtoothed grain beetle Oryzaephilus surinamensis (Linneaus, 1758) (Silvanidae) were most abundant on tamarind. The hymenopterans Theocolax elegans (Westwood, 1874) (Pteromalidae), Anisopteromalus calandrae (Howard, 1881) (Pteromalidae) and Cephalonomia waterstoni (Gahan, 1931) (Bethylidae) were the dominant parasitoids of larvae and pupae of the storage pests. Simpson index of diversity of insect species across locations ranged from low (0.63) to high (0.89).

Abstract. The objective of this project was to determine the effect of hermetic storage conditions on red flour beetle (Tribolium castaneum) and maize weevil (Sitophilus zeamais), and to hopefully reduce infestation during storage. This project used 4 oz. glass jars and vacuum grease to provide hermetic storage conditions. Red flour beetles (Tribolium castaneum) were placed in jars filled with wheat, and maize weevils (Sitophilus zeamais) were placed in jars containing corn. We examined counts of live and dead insects over time in both grains, using both hermetic and non-hermetic conditions. After 30 days, statistical analyses were conducted to determine the effects of hermetic vs. non-hermetic conditions for both grains. We found that 100% mortality for red flour beetle (Tribolium Castaneum) was obtained after 12 days for wheat under hermetic conditions. We also found 100% mortality of maize weevils after 12 days of hermetic storage of corn.

Naturally infested paddy rice was used to compare the effectiveness of polypropylene bags and hermetic storage containers over 12 months of storage in a warehouse. Insect pest identification as well as the infestation level, percentage of damaged grain, weight loss, and moisture content were evaluated. Five insect species associated with stored rice were identified during the storage period, namely lesser grain borer (Rhyzopertha dominica), red flour beetle (Tribolium castaneum), rice/maize weevil (Sitophilus spp.), angoumois grain moth (Sitotroga cerealella) and flat grain beetle (Cryptolestes ferrugineus). The lesser grain borer was the most predominant species with an average incidence above 70% after twelve months of storage, followed by the rice/maize weevil with an incidence of 17%. When compared to hermetic storage containers, polypropylene bag showed the highest mean infestation level with 233.3 individuals/kg after six months of storage, representing about 8-fold of the number of insects recorded in hermetic containers after six months of storage. In polypropylene container, the percentage of damaged grain and weight loss increased significantly achieving a maximum of 6.98% and 5.56% respectively, whereas using hermetic containers the highest percentage of damaged grain reached was 3.24% in polyethylene drum and the weight loss was 1.62% in GrainSafe bag. The results from the study show that the use of hermetic storage containers is a green alternative for safe storage of paddy rice, for 12 months without application of pesticides, bringing multiple advantages for smallholder farmers, lever food security and income generation for smallholder farmers and rice milling companies.

We evaluated the susceptibility to phosphine in different populations originated from 14 European countries, by following different diagnostic protocols. In total, more than 200 populations were screened during these tests, classified to 9 beetle species: Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Sitophilus granarius (L.) (Coleoptera: Curculionidae), Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) and Lasioderma serricorne (F.) (Coleoprtera: Anobiidae). The different bioassay-related diagnostic protocols that were followed were based on different exposure intervals and phosphine concentrations, ranging between 90 min and 4 d, and between 30 and 3000 ppm, respectively. Our results indicated that one of the populations that had been sampled from Europe was strongly resistant to phosphine. Moreover, the different protocols provide comparable results, which means that a standardized diagnostic can be further designed and adopted. Moreover, molecular assays indicated that the mutations P49S in R. dominica and P45S in T. castaneum are common among different populations, regardless of the degree of resistance to phosphine. Our results suggest that there are reliable quick tools for the evaluation of resistance to phosphine and that insect sampling in target areas should be conducted on a regular basis.

Insect α‐amylase inhibiting and/or growth inhibiting activities of proteinaceous inhibitors from red kidney bean (Phaseolus vulgaris) and hard red winter wheat (Triticum aestivum) were examined. The bean inhibitor was most effective in vitro against α‐amylases from the red flour beetle (Tribolium castaneum) and the confused flour beetle (T. confusum), followed by those from the rice weevil (Sitophilus oryzae) and yellow mealworm (Tenebrio molitor). The insect enzymes were from two‐ to 50‐fold more susceptible than human salivary α‐amylase. When the inhibitors were added at a 1% level to a wheat flour plus germ diet, the growth of red flour beetle larvae was slowed relative to that of the control group of larvae, with the bean inhibitor being more effective than the wheat inhibitor. Development of both the red flour beetle and flat grain beetle (Cryptolestes pusillus) was delayed by 1% bean inhibitor, but development of the sawtoothed grain beetle (Oryzaephilus surinamensis) and lesser grain borer (Rhyzopertha dominica) was not affected by either the bean or wheat inhibitor at the 1% level. Rice weevil adults fed a diet containing 1% bean or wheat inhibitor exhibited more mortality than weevils fed the control diet. When the wheat amylase inhibitor was combined with a cysteine protease inhibitor, E‐64, and fed to red flour beetle larvae, a reduction in the growth rate and an increase in the time required for adult eclosion occurred relative to larvae fed either of the inhibitors separately. The bean inhibitor was just as effective alone as when it was combined with the protease inhibitor. These results demonstrate that plant inhibitors of insect digestive enzymes act as growth inhibitors of insects and possibly as plant defense proteins, and open the way to the use of the genes of these inhibitors for genetically improving the resistance of cereals to storage pests.

Evaluation of spinosad as a grain protectant on three Kansas farms