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Laboratory bioassays were conducted to evaluate the insecticidal efficacy of a diatomaceous earth deposit from Greece, for a wide range of stored product insects. In this context, populations of five different insect species, Tribolium confusum Jacquelin DuVal, the confused flour beetle, Sitophilus oryzae (L.), the rice weevil, Rhyzopertha dominica (F.), the lesser grain borer, Oryzaephilus surinamensis (L.), the sawtoothed grain beetle, Cryptolestes ferrugineus (Stephens), the rusty grain beetle, which cover a major spectrum of insects species of stored products worldwide, were used in the bioassays. The different treatment of diatomaceous earth (DE) rocks (grinding, diatomaceous enrichment, powder granulometry) led to the creation of five types of formulations (namely DE1, DE2, DE3, DE5 and DE6) that exhibited significant fluctuations in their insecticidal efficacy when applied on wheat. In general, some of the modified formulations were found to be very effective against species such as R. dominica and T. confusum that may be difficult to control at the current labeled doses of commercial DE formulations. Overall, our data clearly indicate that this specific Greek deposit has considerable insecticidal properties, which can be further utilized in designing commercial formulations for insect control at the postharvest stages of durable agricultural commodities, provided that the deposit will be modified at specific enrichment and granulometry levels.

Bioassays were conducted to evaluate the effectiveness of thiamethoxam in different surfaces, against six stored-grain insects, Sitophilus granarius (L.) (Coleoptera: Curculionidae), Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), and Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). Six different surfaces (concrete, plywood, galvanized steel, linen, plastic, and ceramic tile) treated with thiamethoxam at 0.05 and 0.1 mg/cm2 were used as substrate for adult exposure. Knockdown was recorded after 1, 3, and 7 d of exposure to the treated surface, in order to calculate a Standardized Lethality Index (SLI). Knockdown counts were ranked from ‘0’ to ‘4’, with ‘0’ representing adult insects ‘moved generally’ and ‘4’ representing dead insects. Based on the results, insect knockdown seems leading to mortality than to recovery and the SLI ranking of the target species according to their susceptibility to thiamethoxam showed that S. granarius being more susceptible and decreasing susceptibility in an order of S. oryzae > T. castaneum ≥ O. surinamenis ≥ C. ferrugineus ≥ T. confusum. In general, among the surfaces, thiamethoxam efficacy was lower on linen, wooden, and concrete surfaces, as compared to metallic and plastic surfaces. Nevertheless, at the end of 7-d exposure, all surfaces equally affected thiamethoxam toxicity.

The use of chemical insecticides has had several side-effects, such as environmental contamination, foodborne residues, and human health threats. The utilization of plant-derived essential oils as efficient bio-rational agents has been acknowledged in pest management strategies. In the present study, the fumigant toxicity of essential oil isolated from Satureja intermedia was assessed against cosmopolitan stored-product insect pests: Trogoderma granarium Everts (khapra beetle), Rhyzopertha dominica (Fabricius) (lesser grain borer), Tribolium castaneum (Herbst) (red flour beetle), and Oryzaephilus surinamensis (L.) (saw-toothed grain beetle). The essential oil had significant fumigant toxicity against tested insects, which positively depended on essential oil concentrations and the exposure times. Comparative contact toxicity of S. intermedia essential oil was measured against Aphis nerii Boyer de Fonscolombe (oleander aphid) and its predator Coccinella septempunctata L. (seven-spot ladybird). Adult females of A. nerii were more susceptible to the contact toxicity than the C. septempunctata adults. The dominant compounds in the essential oil of S. intermedia were thymol (48.1%), carvacrol (11.8%), p-cymene (8.1%), and &gamma, terpinene (8.1%). The high fumigant toxicity against four major stored-product insect pests, the significant aphidicidal effect on A. nerii, and relative safety to the general predator C. septempunctata make terpene-rich S. intermedia essential oil a potential candidate for use as a plant-based alternative to the detrimental synthetic insecticides.

To assess the susceptibility of pseudocereals (amaranth and quinoa), minor cereals (teff and millet), and oilseeds (chia and hemp), now commercially available on the European market, to attacks by polyphagous and cosmopolitan insect pests, laboratory tests were set up. Tests involving controlled infestation of seeds, using laboratory-bred insects (Tenebrio molitor, Tribolium confusum, Oryzaephilus surinamensis, Cryptolestes pusillus and Plodia interpunctella), were carried out in a climatic chamber at 23 ± 2 °C and 65 ± 5% R.H.. Development time, the number of adults and the weight of these adults were evaluated. The results show that each considered foodstuff has a different susceptibility to infestation and differences both in the number of adults emerged and in their weight compared to control. Millet was the only product that allowed larval development up to the adult stage for all the species examined. No species developed on amaranth. T. confusum and O. surinamensis reached the adult stage on the greatest number of products, 5 and 4 respectively; C. pusillus and T. molitor completed their life cycles on only two commodities: millet and teff, while P. interpunctella only on millet and hemp seeds. Considering the impact of the different pests on the studied grains, T. confusum was the only species able to develop on all the grains, but the number of emerged adults was lower than on the standard diet. These results show that, even if these commodities are new in the European market, they are susceptible to the infestation of common stored product pests that could led to a removal from the market of a contaminated stock, so a continuous monitoring is needed.

Animals engage in a plethora of mutualistic interactions with microorganisms that can confer various benefits to their host but can also incur context-dependent costs. The sawtoothed grain beetle Oryzaephilus surinamensis harbors nutritional, intracellular Bacteroidetes bacteria that supplement precursors for the cuticle synthesis and thereby enhance desiccation resistance of its host. Experimental elimination of the symbiont impairs cuticle formation and reduces fitness under desiccation stress but does not disrupt the host&rsquo, s life cycle. For this study, we first demonstrated that symbiont populations showed the strongest growth at the end of metamorphosis and then declined continuously in males, but not in females. The symbiont loss neither impacted the development time until adulthood nor adult mortality or lifespan. Furthermore, lifetime reproduction was not influenced by the symbiont presence. However, symbiotic females started to reproduce almost two weeks later than aposymbiotic ones. Thus, symbiont presence incurs a metabolic and context-dependent fitness cost to females, probably due to a nutrient allocation trade-off between symbiont growth and sexual maturation. The O. surinamensis symbiosis thereby represents an experimentally amenable system to study eco-evolutionary dynamics under variable selection pressures.

Cuticular hydrocarbons (CHCs) of host insects are used by many parasitic wasps as contact kairomones for host location and recognition. As the chemical composition of CHCs varies from species to species, the CHC pattern represents a reliable indicator for parasitoids to discriminate host from non-host species. Holepyris sylvanidis is an ectoparasitoid of beetle larvae infesting stored products. Previous studies demonstrated that the larval CHC profile of the confused flour beetle, Tribolium confusum, comprises long chain linear and methyl-branched alkanes (methyl alkanes), which elicit trail following and host recognition in H. sylvanidis. Here we addressed the question, whether different behavioral responses of this parasitoid species to larvae of other beetle species are due to differences in the larval CHC pattern. Our study revealed that H. sylvanidis recognizes and accepts larvae of T. confusum, T. castaneum and T. destructor as hosts, whereas larvae of Oryzaephilus surinamensis were rejected. However, the latter species became attractive after applying a sample of T. confusum larval CHCs to solvent extracted larvae. Chemical analyses of the larval extracts revealed that CHC profiles of the Tribolium species were similar in their composition, while that of O. surinamensis differed qualitatively and quantitatively, i.e. methyl alkanes were present as minor components on the cuticle of all Tribolium larvae, but were absent in the O. surinamensis CHC profile. Furthermore, the parasitoid successfully recognized solvent extracted T. confusum larvae as hosts after they had been treated with a fraction of methyl alkanes. Our results show that methyl alkanes are needed for host recognition by H. sylvanidis.

In recent years, the use of plant derivatives such as essential oils has been considered as a substitute for chemical pesticides in pest control. Essential oil of Cyperus rotundus L. rhizomes was extracted by hydrodistillation and its compounds were identified by GC/MS. Also, the contact toxicity and repellent activity of essential oil against adults Callosobruchus maculatus F., Oryzaephilus surinamensis L., and Trogoderma granarium Everts were evaluated in the laboratory (27 ± 2 °C, 65 ± 5% relative humidity, and dark conditions). The results showed that elemenone (13.59%), α-cyperone (13.14%), and caryophyllene oxide (13.03%) were the major constituents of essential oil. The values of LC50 for C. maculatus, O. surinamensis, and T. granarium in contact toxicity were 0.36, 0.51, and 0.2 μL/cm2, respectively. The repellency percentage of essential oil on O. surinamensis, T. granarium, and C. maculatus was 94%, 94%, and 80% after 2 h, and 90%, 92% and 70% after 4 h, respectively. According to these results, essential oil of C. rotundus can be used as a suitable substitute for chemical pesticides to protect the stored products against pests.

Grain aeration with ambient air is the primary method used in France to prevent and control insect infestations. French grain storage operators consider that complete total mortality of insects can be achieved by maintaining grain temperature at 5 °C for 3 months. A predictive model on insect survival at low temperature was developed, using data from literature to test this hypothesis on Sitophilus oryzae, Sitophilus granarius, Rhyzopertha dominica, Cryptolestes ferrugineus, Oryzaephilus surinamensis, Tribolium castaneum and Tribolium confusum. A Cox proportional hazard regression, belonging to survival analysis, was associated to a Receiver Operator Analysis to evaluate the model and to predict durations of cold exposure required to obtain a total mortality for each species at different developmental stages and temperatures. The model described well the data since occurrence or not of a total mortality was correctly described in 77.2% of all cases. Computed predictions highlighted the facts that species cold-tolerance ranking varied depending on the temperature levels and that difference of cold tolerance between adult and immature stages depended greatly on species. A temperature of 0 °C is sufficient to kill all insect populations within 3 months, except Cryptolestes ferrugineus ones. However, a temperature of 5 °C is highly insufficient to achieve a total mortality. Practical implementations of this work are discussed.

Insect survival after exposure to 0 °C for 7 days was examined in laboratory bioassays for control of adults of six major stored-product beetle species, Oryzaephilus surinamensis (L.), the sawtoothed grain beetle, Cryptolestes ferrugineus, (Stephens), the rusty grain beetle, Dermestes maculatus DeGeer, the hide beetle, Sitophilus oryzae (L.), the rice weevil, Tribolium castaneum (Herbst), the red flour beetle, and T. confusum Jacquelin DuVal, the confused flour beetle In this test there were four different acclimation treatments, insects that had been subjected to a pre-acclimation period to 0 °C, a post-acclimation period, both a pre and post-acclimation period, and adults that were not acclimated. Insect survival for all species except S. oryzae was not affected by the exposure to 0 °C, regardless of the acclimation scenario. In contrast, exposure to 0 °C drastically reduced survival of S. oryzae. Moreover, adults that were exposed to the post-acclimation only and un-acclimated adults had lower survival rates than those that had either exposure to pre-acclimation, or to both pre- and post-acclimation. Results of this experiment show that acclimation played a limited role in adult survival of five of the six tested species, and that exposure of adults to 0 °C for 7 d had no effect in survival of these species as well.

Color preferences on post-harvest adult pests are useful for monitoring instrument development which based on the colonization and oviposition behavior. The research was aimed to determine the most attractive color with a certain wavelength for the test insects. The research was conducted in laboratory conditions of Plant Pest Laboratory, Department of Plant Pest and Disease, Faculty of Agriculture, University of Brawijaya at 27 ± 2°C, RH 65 ± 5%; and day:light 12:12 hours. Study of color preferences on six species of weevil used free choice test method and set by CRD with four replications using eight colors: white, red, orange, yellow, green, blue, indigo, and purple. The observed parameters were the number of adults and eggs laid. Results showed that each post-harvest insect had a different preference for various colors in the range of 380–450 nm wavelength. Adults of Sitophilus oryzae, Oryzaephilus surinamensis, O.s Mercator, and Tribolium castaneum were more preferred to feed and lay eggs in blue color (451–495 nm), Lasioderma serricorne was more preferred in indigo color (445–450 nm), and S. zeamais was more preferred in purple color (380–444 nm). The oviposition preference revealed that there was a positive correlation between the number of females and the egg laid.

Raisins are one of the most important Iranian export products but are threatened by various storage pests. Because of the disadvantages of fumigants, we evaluated alternative microwave and ozone methods for their disinfection and the side effects on raisin qualities. To perform microwave disinfection, the studied raisin samples were exposed to microwave powers of 450, 720, and 900 W for 20, 30, 40, and 50 s. Also, ozone treatments included various combinations of ozone concentrations (2, 3, and 5 ppm) and exposure times (15, 30, 45, 60, and 90 min). An image processing technique was implemented to determine the color changes of raisins in terms of lightness, redness, yellowness, total color difference, chroma, and hue angle. The results revealed that increasing the microwave power and exposure time might lead to further changes of the previously mentioned color characteristics. Compared with the microwave treatments, ozone treatments had fewer effects on those features. Generally, microwave and ozone methods could successfully disinfect Oryzaephilus surinamensis in raisins, with acceptable changes in all the color characteristics. Hence, the previously mentioned methods are proposed as alternative chemical fumigants.

In the present work, a lethality index was applied for the evaluation of three insecticides with different modes of action, i.e., thiamethoxam, chlorfenapyr and lambda-cyhalothrin, as surface treatment against adults of Sitophilus oryzae (L.), Oryzaephilus surinamensis (L.) and Tribolium confusum Jacquelin du Val, in laboratory bioassays. The insecticides were applied at their highest label dose, while insect knockdown and mortality were evaluated after 1, 3, 5 and 7 days of exposure to the treated surfaces according to the Standardized Lethality Index, by ranking each insect from “0” to “4,” with “0” corresponding to insects moving normally and “4” corresponding to dead individuals. After the end of the exposure, the surviving insects were transferred to clean, untreated dishes and delayed mortality was assessed after an additional period of 1, 3, 5 and 7 days. Based on the results, initial knockdown was high for S. oryzae after exposure to thiamethoxam and lambda-cyhalothrin even after 1 day of exposure, whereas for longer exposures high mortality levels were recorded. In contrast, in the case of chlorfenapyr knockdown was low after 1 day of exposure; however, high mortality levels were noted after 3 and 5 days of exposure. Similar results were noted for O. surinamensis, which was highly susceptible to all three insecticides tested. The most tolerant insect species to the tested insecticides was T. confusum, since a noticeable number of T. confusum adults were still active at the end of the exposure (7 days). Our results indicate that knockdown is most likely to lead to mortality than to recovery, but there were important differences among the three insecticides tested.

Laboratory tests were carried out to examine the efficacy of different exposure intervals (2 h, 4 h, 8 h, 1 d, 2 d, 3 d, and 7 d) on different life stages (adults, pupae, larvae, and eggs) of Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), the confused flour beetle, and Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), the saw-toothed grain beetle (adults, larvae, and eggs) to 0, -5, -10, and -15°C. Larvae and pupae of T. confusum were more cold-tolerant than eggs or adults. Exposure to temperatures of -10°C for 1 d will kill nearly 100% of all life stages of T. confusum. O. surinamensis was more cold-tolerant than T. confusum. Adults of O. surinamensis were not killed when exposed for 1 d at -5°C, but egg hatch was drastically reduced after 2 h of exposure at the same temperature. Eggs and adults of O. surinamensis were more cold-tolerant than larvae. Our study indicates that target insect species and life stage, temperature, and exposure interval should all be considered when cold treatment is selected as a control strategy against T. confusum and O. surinamensis. Facility managers can use these data in planning cold treatments.

A detection and identification method for stored-grain insects was developed by applying deep neural network. Adults of following six species of common stored-grain insects mixed with grain and dockage were artificially added into the developed insect-trapping device: Cryptoleste Pusillus(S.), Sitophilus Oryzae(L.), Oryzaephilus Surinamensis(L.), Tribolium Confusum(Jaquelin Du Val), Rhizopertha Dominica(F.). Database of Red Green and Blue (RGB) images of these live insects was established. We used Faster R-CNN to extract areas which might contain the insects in these images and classify the insects in these areas. An improved inception network was developed to extract feature maps. Excellent results for the detection and classification of these insects were achieved. The test results showed that the developed method could detect and identify insects under stored grain condition, and its mean Average Precision (mAP) reached 88.

Laboratory bioassays were conducted to evaluate the efficacy of two insecticides, spinetoram and thiamethoxam, applied alone or in combination to wheat against adults of Sitophilus granarius, S. oryzae, Oryzaephilus surinamensis, Tribolium castaneum and Cryptolestes ferrugineus, as well as adults and larvae of T. confusum. Spinetoram was applied at two (0.25 and 0.5 ppm) and thiamethoxam at three (1, 2 and 5 ppm) dose rates, whereas all binary combinations of the insecticide concentrations were also tested. Insect mortality was determined after 1, 2, 7, 14 and 21 d of exposure, while 65 d later progeny production was evaluated. In the case of T. confusum larvae, adult emergence was estimated 4 weeks after the initiation of the bioassays. Among the species examined, S. granarius and S. oryzae were the most susceptible to spinetoram in terms of parental mortality, however progeny production was significantly suppressed only in the case of S. granarius. In contrast, O. surinamensis, T. confusum and T. castaneum were the least susceptible to the specific dose rates of spinetoram tested. Thiamethoxam was effective against all species tested providing high levels of parental mortality and progeny production suppression. However, the combined application of thiamethoxam and spinetoram at the specific dose rates tested did not exhibit any additive or synergistic effect against the stored-product beetle species examined. Still, the combined application of these active ingredients did not exhibit any antagonistic effect.

Efficacy of different doses of the Beauveria bassiana-IRAN441C alone (66,125, 250, 500, 1000 mg conidia. Kg−1 grains) and combined with a low-lethal dose (LD25) of diatomaceous earth (DE) SilicoSec® as lethal agents were assessed against the adults of Callosobruchus maculatus (F.) (Chrysomelidae) on mung, and cowpeas, and Oryzaephilus surinamensis (L.) (Silvanidae) on wheat and barley seeds. In both species, mortality reached 60–73% in B. bassiana alone and 83–100% in fungus combined with the DE at the highest dose. A synergistic effect between B. bassiana conidia and the DE was confirmed. The DE low-lethal dose alters fungal mycosis and sporogenesis (conidia mL−1) rates in the infected cadavers. The adult populations of both species were suppressed desirably despite a decrease in the number of cadaver-derived mycosis and their spore production at the highest combination doses (1000 mg kg−1+ LD25 of DE). Seed type had no significant effect on mycosis and sporogenesis on both insects in several combination doses. The cadaver-derived aerial conidia germination rate was increased in the presence of DE low-lethal dose, but it declined by increasing the fungal dose. Type of commodity failed to affect the germination rate of O. surinamensis-derived conidia; however, the mung bean intensified this case for another insect. In both beetles, offspring's emergence was suppressed dose-dependently seven weeks after removing exposed parents to the lethal agents as well it was more in doses mixed with DE. The most significant reduction in progeny production of treated C. maculatus occurred on cowpeas and that of treated O. surinamensis on wheat seeds. Our findings demonstrate that DE's low-lethal dose enhances the virulence of B. bassiana in the various mixtures synergistically, and co-applications of the two substances were feasible. As well, the lethal agents' adverse effects were found to carry over onto both species' offspring during two-month storage time.

Sawtoothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), is a secondary pest of stored products and one of the serious insect pests of cereal grains, commodities and packaged food throughout the world. However, this species is a concern beyond cereal grains, what may be differentially affected by temperature. Therefore, insect developmental time, larva and pupa survival, and adult emergence of O. surinamensis were assessed on different substrates (rice, sesame and date palm) at different temperatures (20, 25, 30 and 35 °C and 65% r.h). The substrate loss incurred by this insect infestation was also recorded. The larval stage was the main determinant for the overall developmental time of the sawtoothed grain beetle, regardless of the substrate and temperature tested. Adult emergence was affected by substrate (F2,48 = 4.50, P = 0.02) and particularly temperature (F3,48 = 24.94, P

In this study the adulticidal and larvicidal effect of tansy, Tanacetum vulgare L. (Asteraceae) essential oil (EO) was estimated against four noxious stored-product insect species; Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). The EO chemical composition, as determined by GC-MS, was dominated by oxygenated monoterpenes (68.2%), with borneol (13.6%), umbellulone (11.7%), artemisia ketone (9.3%), cis-chrysanthenol (6.9%), camphor (5.9%), and terpinen-4-ol (5.5%) as the major constituents. This profile was quite different from those previously reported from other T. vulgare European accessions which are characterized by high content of the toxic trans-thujone. The T. vulgare EO was applied as wheat protectant at two concentrations of 500 and 1000 ppm. Adult and larval mortality levels were estimated after 4, 8 and 16 h and 1, 2, 3, 4, 5, 6 and 7 days. Tanacetum vulgare EO caused complete mortality (100%) to T. castaneum larvae, but only 25.6% to adults at 1000 ppm 6 and 7 days post-exposure, respectively. The mortality rates of T. confusum larvae and adults were 56.7 and 8.9% on wheat treated with 1000 ppm EO, respectively after 7 days of exposure. The EΟ caused moderate mortality to T. molitor adults (52.2%), and low mortality to larvae (8.9%), at 1000 ppm at the end of the experimental period. High mortality of O. surinamensis larvae (93.3%) was noticed at 1000 ppm after 7 days of exposure, while only 13.3% of the exposed adults were dead at the same concentration and exposure interval. Overall, the T. vulgare EO could be considered as a potential wheat protectant for the management of important stored-product insects. However, its efficacy depends on the species and the life stage of the target pest.

This review compares research techniques, plant species and forms of their application in worldwide studies on the repellent activity of plant material against storage pests, such as Sitophilus oryzae, Sitophilus granarius, Tribolium castaneum, Rhyzopertha dominica and Oryzaephilus surinamensis. Over 300 plant extracts, essential oils and powders were tested against these five insect species with various methods. The intensity of repellency of the examined plant products against each considered pest species was presented. Evaluation of the repellency potential of particular plant extracts, oils and powders showed that insect repulsion increased with their concentration. Duration of exposure was also an important factor affecting repellent activity.

This study aimed to evaluate the effect of pressurized CO2, N2 and atmospheric air against the immature stages and adults of two secondary insect species of stored products [Oryzaephilus surinamensis (L.) and Stegobium paniceum (L.)]. The insects were exposed to 5 levels (1-5 bars) of the pressurized gases in a metal gas cylinder for two exposure periods (one day and two days) at average of 20°C. The results showed generally that, Co2 was the most effective as it induced the highest mortality percentages followed by N2 then atmospheric air. Sensitivity of the two tested insect species to CO2 and N2 was approximately the same, while S. paniceum was more sensitive to the pressurized air than O. surinamensis. Egg stage of the two insect species was the more tolerant stage, while adult stage exhibits the highest level of sensitivity to all tested gases for any level of pressure and the both periods of exposure. Larvae of S. paniceum as exceptional case were more tolerant to the pressurized CO2 than the other stages. It was noticed also that mortality of all insect stages of both species was significantly increased as the exposure period to the tested gases increased. Mortality of insects increased as the level of gas pressure increased recording the highest percentages of insect mortality at the highest level of gas pressure (5 kg/cm2).

In the present study, the residual efficacy of an alpha-cypermethrin-coated net (Carifend®, BASF AG, Ludwigshafen, Germany) was evaluated in laboratory studies against four species of stored product insects. The insecticide-treated net was fitted into the bottom of plastic petri dishes, whereas two other sets of dishes (without net, with net without insecticide) served as controls. The insects used in the bioassays were Sitophilus oryzae, Tribolium confusum, Oryzaephilus surinamensis and Prostephanus truncatus. Adults of these species were exposed every 30 d for a total of 90 consecutive days in total. Based on the results, the insecticidal effect of the net remained at high levels during the entire experimental period, indicating its high residual effect. Among the species tested, T. confusum was the least susceptible. Carifend® can be a valuable tool for the protection of stored products against storage insects, and its use can be further examined towards this direction.

The insect's response to various living substrates is an important determinant for their life history and demography reflected in their feeding and egg-laying preferences. However, research on polyphagous stored product insects such as the sawtoothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), are largely focused on cereal grains neglecting its alternative hosts. Therefore, this study examines the effect of a range of 16 host substrates including dry fruits, nuts, oil and legume seeds on insect development, survival, and adult emergence of the sawtoothed grain beetle, besides of also determining the feeding substrate weight loss. Overall, the feeding substrates exhibited a significant and different effect on O. surinamensis, except egg incubation time and length of the pupal period. The longest larval periods were observed on legumes followed by oilseeds and (dry) fruits. The highest survival and adult emergence were recorded on fruits and nuts, except raisin, but significantly lower than when fed on legume seeds, including soybean. The losses in fruits and nuts were higher, particularly on almonds and cashew. Larva development was inversely correlated to survival and adult emergence, which were positively correlated to substrate loss. Our study indicated that several non-grain commodities such as (dry) fruits and nuts are rather suitable substrates for the population growth of O. surinamensis, an additional concern for in international trade.

Bioassays were carried out in order to assess the insecticidal value of the neonicotinoid thiamethoxam in different concentrations against seven important beetle species that are major pests of stored grains. These species were Prostephanus truncatus (Horn), Rhyzopertha dominica (F.), Sitophilus oryzae (L.), Sitophilus granarius (L.), Oryzaephilus surinamensis (L.), Tribolium confusum Jacquelin du Val, and Cryptolestes ferrugineus (Stephens). Adults of these species were exposed to grains treated with thiamethoxam at dose rates of 0 (control), 0.01, 0.1, 0.5, 1, 2, 5 or 10 ppm. Our results indicate that with the increase of the insecticide concentration, there was also an increased adult mortality and a reduction in progeny production. To illustrate the relative sensitivity to thiamethoxam of the seven insects, starting with the most susceptible, we can classify them as P. truncatus > R. dominica = S. granarius = S. oryzae > T. confusum = O. surinamensis > C. ferrugineus. The findings of the present research show that thiamethoxam can be recommended for its efficacy at a rate of 10 ppm and duration of 14 days that could be used to control all insects and their progeny.

The efficacy of low temperatures ranging from 0 to −15 °C was evaluated against all life stages of Tribolium confusum, adults of Oryzaephilus surinamensis and adults of Liposcelis bostrychophila. All species/life stages were exposed in empty vials or vials containing 5 g of flour, for time intervals of 2–7 d. Eggs and pupae were the least susceptible life stages of T. confusum, as these life stages had the highest survival at – 15 °C. Nevertheless, at this temperature, an exposure of 4 and 8 h for eggs and pupae, respectively, resulted in no survival. In most combinations, the presence of flour did not affect survival of T. confusum exposed to any temperature. There was no survival of O. surinamensis adults after exposure to −5 °C for 7 d or to −10 °C for 8 h, and the presence of flour had no effect on survival. Adults of L. bostrychophila were the most-cold tolerant among the species and life stages tested; at −10 °C, mortality was 100% only after 7 d of exposure. For this species, the presence of flour had some effect on adult survival, but results were not consistent with temperature. The results of this study can be utilized to develop control programs for using low temperatures as a disinfestation strategy for infested commodities.

In the present work, the distribution of phosphine gas in metal shipping containers was modeled and compared with available data from phosphine sensors. Two different sizes of containers, 20 and 40 ft, were used in the experiments with different doses for each treatment. In each container, sensors were placed to monitor the distribution of phosphine, along with vials with phosphine –susceptible and –resistant insect populations. The insects used in the experiments were the Rhyzopertha dominica (F.) and Oryzaephilus surinamensis (L.), which are two of the most common species found in stored products. A Computational Fluid Dynamic (CFD) model was developed using the OpenFoam software and combined with phosphine sensors for precision fumigation practices. Gas transport and sorption effects of phosphine into empty and filled containers were considered in the CFD model. In light of our findings, in an empty container, the phosphine concentration was approximately similar for all locations, while in the filled container there were noticeable variations inside the fumigated area. Moreover, there was a time delay for phosphine to reach the sensors that were submerged inside the fumigated commodity, at the rear side of the containers. Regarding the simulations, the predictions of the computational model were in accordance with the phosphine concentration as recorded by the sensors. Concerning insect mortality data, in most of the cases, for both species, complete control was noted, regardless of the resistance level of the population tested. These results indicated that the CFD correlated well with the phosphine concentration and insect mortality and thus, a methodology for precision fumigation in containers can be further established.

Hemp, or industrial hemp (Cannabis sativa), is a high value alternative crop that has seen increases in production in Canada since commercial production was legalized in 1998. Insect infestation of stored hemp seed may result in loss of quality and value. There are few published studies on the ability of insects to survive and reproduce on hemp seed. Reproduction of eleven stored-product insects on hemp seed at different moisture contents with, or without dockage, was studied. Insects were introduced into 15 g of hemp seed at two initial moisture contents (dry, 9% m.c. or damp, 15% m.c.), two dockage levels (dockage-free or dockage, 15%), and held at 30°C and 60–70% r.h. Five replicates of each treatment for each species were used. For beetles, twenty unsexed adults were used, for Ephestia kuehniella (Mediterranean flour moth), twenty eggs were used. For the beetles, live and dead adults were counted after 3, 5, 7 and 9 weeks, for the moth, adults were counted after 12.5 weeks. After counting, only live adults were returned to the hemp seed. The following beetle populations increased over the 9 weeks; Tribolium castaneum (red flour beetle), Lasioderma serricorne (cigarette beetle), Oryzaephilus surinamensis (sawtoothed grain beetle) and Trogoderma variabile (warehouse beetle). The following species did not increase their populations; Cryptolestes ferrugineus (rusty grain beetle), Rhyzopertha dominica (lesser grain borer), Sitophilus oryzae (rice weevil), Cryptolestes turcicus (flour mill beetle), Tribolium confusum (confused flour beetle), and Stegobium paniceum (drugstore beetle). For the beetles, higher dockage generally led to higher populations. The effect of moisture content was variable. Ephestia kuehniella produced adults on all treatments, with the dry treatment containing dockage performing the best.

The insecticidal activity of nanosilica particles (NSPs) [20 ± 4 nm] was determined using the saw-toothed grain beetle, Oryzaephilus surinamensis (L) adults as the experimental insect. When the unsexed adults were exposed to different doses of nanosilica (0.2, 0.4, 0.6, 0.8 and 1.0 mg/Petri dish) for different periods (1, 2 and 3 days), it was found that NSPs had more insecticidal activity against O. surinamensis. Moreover, it was found that as the exposure time and dose increased, the mortality percentages of the adults increased. When the adult fed on irradiated dates which treated with different doses of nanosilica (0.5, 1,2 and 4 mg/1date) the mortality was higher than in nanosilica alone. The LD50 of the bioassay tests showed that the calculated LD50 values of each treatment were 0.468, 1.201 and 0.572 mg/1date. The adult of O. surinamensis (untreated, treated with LD50 of nanosilica and fed on unirradiated or irradiated dates) examined by a scanning electron microscope. The examination showed the same malformations in all treatments which caused abrasion and damage on the outer surface. Nanosilica can be effectively replacing chemical insecticides to protect stored products.

Commercial grain elevator and feed mill facilities can quickly become infested with stored-product insect pests, compromising the protection of the stored raw and processed cereal products. Elevators and feed mills were sampled monthly for adult stored-product insects in grain residues from the boot-pit areas and in bulk load-out samples from 2009 to 2010. The grain samples collected from the boot, pit, and load-out areas consisted of corn, soybeans, or a mixture of the two grains. Low insect densities were found in the boot-pit area during the cool winter months. Insect numbers increased in the spring and peaked during the warm summer months, prior to declining in the fall following a pattern of higher insect densities during higher ambient temperatures. The rice weevil, Sitophilus oryzae (L.), was the most prevalent species collected in all of the sampled grain residues, representing 69.2 and 35.8% of total insects collected in feed mills and elevators, respectively, during 2009 and was also commonly collected in 2010. Other commonly collected insect species included, the red flour beetle, Tribolium castaneum (Herbst); rusty grain beetle, Cryptolestes ferrugineus (Stephens); and sawtoothed grain beetle, Oryzaephilus surinamensis (Linnaeus). Our results showed that failing to clean out boot residual grain and a lack of sanitation of the pit area resulted in high numbers of insects that were transferred through the elevator leg to other locations within a facility. We conclude that the lack of sanitation at elevator and feed mill facilities allowed high numbers of insects to develop.

Ozone is a powerful oxidant which can be used for killing insects and microorganisms. In this study, ozone was applied in the gaseous form to control two species of pests in stored dried figs. The samples of figs (50 g each) were infested with adults of Oryzaephilus surinamensis L. and larvae of Ephestia kuehniella Zeller and were subjected to different combinations of ozone concentrations (2, 3, and 5 ppm) and exposure times (15, 30, 45, 60, and 90 min). Changes in organoleptic properties (color, sweetness, firmness, aroma, and overall acceptability) during ozonation were studied. The results showed that the mortality rate increased with an increase in ozone concentration and exposure time. The total mortality of both pests was achieved at an ozone concentration of 5 ppm and exposure time of 90 min. Sensory evaluation showed that ozone only had a negligible effect on aroma. Therefore, the usage of ozone is recommended during the postharvest process instead of other chemical fumigants, such as methyl bromide and phosphine.

Mortality of three insects; red flour beetle (Tribolium castaneum Herbst), khapra beetle (Trogoderma granarium Everts) and sawtoothed grain beetle (Oryzaephilus surinamensis (L.)) were evaluated via some aqueous plant extracts. The identification of three examined insects was carried out via designing specific primers for each aforementioned species with the use of PCR technique. The toxicity of aqueous plant extracts; eucalyptus (Eucalyptus camaldulensis Dehnh), mint (Mentha canadensis L.) and myrtle (Myrtus communis L.) at three dosages (12500, 25000 and 50000) ppm for 1, 2, 3 and 7 days were tested for their insecticidal activity against examined adults on dried fruits. Percentage mortality of insect was increased with an increase of doses and exposure times, whereas, not influenced significantly by the fruit types. T. castaneum was the most susceptible species, followed by T. granarium and O. surinamensis. Likewise, LC50 values were (3887.25, 10816.34 & 22763.48) on red flour, khapra & sawtoothed grain beetles respectively via using eucalyptus aqueous extract after 7 days on black raisin. While, higher doses required in order to kill fifty percentage of the population via myrtle aqueous extract and thus the LC50 values increased to (14726.86, 18421.43 & 39016.78) on the three aforementioned species respectively.

Sejak jaman dahulu Indonesia dikenal sebagai penghasil pala dunia. Hingga saat ini Indonesia masih tetap merupakan Negara produsen pala terbesar di dunia yang mensuplai lebih kurang 80 persen kebutuhan dunia. Meskipun Indonesia masih tetap merupakan penghasil utama pala dunia, namun akhir-akhir ini kualitas dan kuantitas pala Indonesia terlihat mengalami penurunan. Salah satu hal yang dapat menyebabkan penurunan tersebut adalah adanya serangan hama, baik yang menyerang pada tanaman di lapang maupun yang merusak pada kondisi pasca panen dalam penyimpanan. Hama utama yang menyerang di lapang adalah penggerek batang Batocera sp., sedang yang menyerang di penyimpanan yaitu Araecerus fasciculatus dan Oryzaephilus surinamensis

Adults of phosphine susceptible laboratory strains and phosphine resistant field strains of five stored-product insect species were exposed in vials with 0 or 10 g of wheat for different time periods to 0.54 g/m3 (200 ppm) of chlorine dioxide gas. After exposure, adult mortality was determined 5 d later at 28 °C and 65% r.h. The 5-d mortality was 100% in laboratory and field strains of the red flour beetle, Tribolium castaneum (Herbst); sawtoothed grain beetle, Oryzaephilus surinamensis (L.); lesser grain borer, Rhyzopertha dominica (F.); maize weevil, Sitophilus zeamais Motschulsky; and rice weevil, Sitophilus oryzae (L.) that were exposed in vials with 10 g of wheat to chlorine dioxide for 26, 16, 24–34, 18–24, and 15–18 h, respectively. Corresponding exposure durations for these species and strains in vials without wheat were 15, 3, 18–20, 7–15, and 5–7 h, respectively. Dosages of chlorine dioxide producing 99% mortality (LD99) of T. castaneum, O. surinamensis, R. dominica, S. zeamais, and S. oryzae strains in vials with wheat ranged from 14.79−22.57, 8.20–8.41, 15.79–21.60, 10.66–14.53, and 7.67–12.20 g-h/m3, respectively. In vials without wheat, corresponding LD99 values for T. castaneum, R. dominica, and S. zeamais strains were 6.51–8.66, 11.46–23.17, and 5.79–10.26 g-h/m3, respectively. LD99 values for O. surinamensis and S. oryzae could not be computed, because of 100% mortality after a 3–5 h exposure to chlorine dioxide. No adult progeny production of T. castaneum and O. surinamensis was observed after 8 weeks in control and chlorine dioxide-exposed samples. Adult progeny production of Sitophilus spp. was found only in the control samples. The dosage for 99% adult progeny reduction relative to control for R. dominica strains ranged from 10.07 to 18.11 g-h/m3. Chlorine dioxide gas is effective in killing phosphine susceptible and resistant strains of five stored-product insect species and suppressing adult progeny production of three out of the five species.