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The efficacy of dry dust and slurry applications of Silico-sec® and Diasecticide™, applied to glass and plastic surfaces, was assessed in the laboratory against the beetles Tribolium castaneum, Sitophilus granarius and Oryzaephilus surinamensis, the mites Acarus siro and Lepidoglyphus destructor, and against larvae of the moth Ephestia kuehniella. For the insects, doses of 5, 10 and 20 g/m2 were evaluated for all preparations, while for the mites 0.5, 1 and 2 g/m2 of the dry dusts, and 2.5, 5 and 10 g/m2 of the slurries were assessed. Mortality was evaluated after 7 days and 24 h for the insects and mites, respectively, in conditions of 15 °C and 80% r.h., chosen to represent typical UK conditions immediately after harvest. The Silico-sec® dry dust was the most effective treatment with mean mortalities ranging from 93–100% for all the pest species at all doses. The Diasecticide™ dry dust was ineffective against T. castaneum and S. granarius with mean mortalities ranging from 86–98% for the other species at the highest dose. With both DEs the slurry applications were generally less effective than the dry dusts at equivalent doses. Oryzaephilus surinamensis was the least tolerant insect species and S. granarius and T. castaneum the most tolerant. The mite A. siro was less tolerant than L. destructor.

Entomopathogenic nematodes (Nematoda: Heterorhabditidae and Steinernematidae) are commonly used biological control agents of insects in cryptic habitats, but their potential for suppressing stored-product insects in these habitats has not been explored previously. Here, we provide data from the first step in a program to evaluate entomopathogenic nematodes in the genus Steinernema as biological control agents of stored-product pests by determining their pathogenicity to some of the major stored-product pest species. When evaluated against larvae, pupae and adults of six pest species (Plodia interpunctella, Ephestia kuehniella, Oryzaephilus surinamensis, Tenebrio molitor, Tribolium castaneum, and Trogoderma variabile), and the adults of two additional pest species (Sitophilus oryzae and Rhyzopertha dominica), Steinernema riobrave was either the most pathogenic or of similar pathogenicity compared to S. carpocapsae and S. feltiae. A dose of 10 infective juveniles of S. riobrave caused 80% or higher mortality against larvae of P. interpunctella, E. kuehniella, T. castaneum, and O. surinamensis, pupae of T. castaneum and T. molitor, and adults of T. molitor and the two moth species. All stages of Trogoderma variabile exhibited 70% or higher mortality. Adults of S. oryzae and R. dominica exhibited low susceptibility with 15% and 35% mortality, respectively. On the basis of these results, S. riobrave was selected for further evaluation under more field-like conditions.

The effects of low pressure (50 mm Hg) and various exposure times were studied on the mortality of three important storage pest insects at 30 °C as part of an effort to eliminate the need for methyl bromide fumigation to control insects in stored commodities, through development of a novel “vacuum-hermetic” technology. Insects were exposed within test chambers containing cocoa beans with a moisture content in equilibrium with 55% relative humidity and at a constant temperature of 30 °C. Three insect species were used: Trogoderma granarium, Lasioderma serricorne and Oryzaephilus surinamensis. At 50±5 mm Hg and 30 °C, the egg was the most resistant stage in all three species at the LT99 level, times needed to obtain 99% mortality being 46, 91 and 32 h, respectively. Adults of T. granarium and L. serricorne, and pupae of O. surinamensis were most susceptible. These results widen the database established to kill insects at low pressure within the framework of practical exposure times and commercially available equipment, in order to provide an effective alternative to fumigation.

Verificou-se a ocorrência de insetos associados a rações industriais para cães e gatos. Coletas simultâneas de péletes foram realizadas após a abertura dos sacos embalados na indústria e distribuídos para comercialização, no período de maio à novembro de 2003. Foram selecionadas para análise, seis diferentes tipos do total das marcas disponíveis para a venda no comércio da cidade do Rio de Janeiro. Registrou-se a incidência dos besouros Necrobia rufipes e Oryzaephilus surinamensis. The occurrence of insects associated with pet foods was verified in simultaneous collections of peletes accomplished after the opening of the sacks wrapped in the industry and distributed for commercialization, in the period of may to november of 2003. There were selected for analysis six different types of the total available marks for sale in the city of Rio de Janeiro. The incidence of the beetles Oryzaephilus surinamensis and Necrobia rufipes was testified.

Effectiveness of the bacterium-derived insecticide, spinosad, was determined against eight storage pests of Australia. Laboratory experiments were carried out on relevant resistant strains of four beetle and four psocid species, with the aim of determining the potential of spinosad as a new grain protectant. To explore the possibility that spinosad could have delayed effects, we exposed all insects for 14 d initially and then a further 14 and 28 d for psocids and beetles, respectively. Adult insects of each strain were exposed to untreated wheat (control) and wheat treated with spinosad at 0.1, 0.5 and 1 mg [a.i.]/kg of grain, and adult mortality and reduction of progeny were determined. Among beetles, spinosad was most effective against Rhyzopertha dominica (F.), with 100% adult mortality and progeny reduction after 14 d exposure at 1 mg [a.i.]/kg. Efficacy of spinosad was less with Sitophilus oryzae (L.), and least with Tribolium castaneum (Herbst) and Oryzaephilus surinamensis (L.). Against the psocids, spinosad was most effective against Liposcelis entomophila (Enderlein), with 100% adult mortality after 28 d exposure at 1 mg [a.i.]/kg and 92% progeny reduction after 14 d exposure and 100% subsequently. Spinosad was only moderately effective against Liposcelis bostrychophila Badonnel, L. decolor (Pearman) and L. paeta Pearman. Our findings suggest spinosad to be a potential protectant against R. dominica and L. entomophila in stored grain in Australia. This potential use would be in combination with another protectant capable of controlling other members of the pest complex.

The relative toxicity of propylene oxide (PPO) at a low pressure of 100 mm Hg to four species of stored product insect at 30 degrees C over a 4-h exposure period was investigated. PPO at 100 mm Hg was toxic to all four species tested: Tribolium castaneum (Herbst), Plodia interpunctella (Hübner), Ephestia cautella (Wlk.), and Oryzaephilus surinamensis (L.). There were differences in susceptibility between the life stages of the tested insect species. Mortality tests on all life stages of the insects resulted in LD99 values ranging from 4.7 to 26.1 mg/liter. The pupal stage of E. cautella, O. surinamensis, and T. castaneum was the most tolerant stage with LD99 values of 14.4, 26.1, and 25.7 mg/liter, respectively. For P. interpunctella, the egg stage was most tolerant, with a LD99 value of 15.3 mg/liter. Generally, PPO at 100 mm Hg was more toxic to P. interpunctella and E. cautella than to O. surinamensis and T. castaneum. A 99% mortality of all life stages of the tested species was achieved at a concentrations x time product of 104.4 mg h/liter. These findings indicate that a combination of PPO with low pressure can render the fumigant a potential alternative to methyl bromide for rapid disinfestation of commodities.

The sawtoothed grain beetle, Oryzaephilus surinamensis (L.), is an important pest of packaged consumer foods, yet little is known of its behavioral response to food odors. Adults and larvae are not believed to chew holes through packaging materials, but they may invade packaged food by entering through openings caused by improper sealing or handling, through holes intentionally placed in packages by the manufacturer, or through openings made by insects or other organisms. To better understand the mechanism of infestation of packaged foods by the sawtoothed grain beetle, we determined how food odor coming through the surface and through holes in consumer food packaging materials influences female sawtoothed grain beetle movement. Mated female beetles responded with an area-concentrated search to the odor of dog food emitted from 0.5-mm-diameter holes punctured in two commonly used food packaging materials (Cello and 120 AB-X). Holes emitting no food odor did not influence beetle behavior. Velocity and distance moved differed between film types, perhaps because of surface characteristics of the film influencing traction, but no influence of food odors coming through the films was detected. This study indicates the necessity for improved package designs and better sealing and handling methods to prevent flaws in packaging through which insects may enter.

The relationship of size of test arena, number of holes in a grain probe trap body and capture of the sawtoothed grain beetle, Oryzaephilus surinamensis (L.), was determined in simulated field tests conducted in an outdoor screen enclosure exposed to natural temperature fluctuations. Polyvinylchloride (PVC) probe bodies were attached to electronic sensor heads, and insect captures were recorded electronically using an electronic grain probe insect counter (EGPIC) system. In comparisons among PVC probe trap bodies with 60, 132, 252, and 492 holes, tested at 18 insects per kilogram in 4.5, 17, and 40 kg of soft wheat in cylindrical arenas (10.2, 20.3, and 30.5 cm in diameter, respectively), number of holes in the probe trap body had no effect on insect capture, but percentage of insects recovered was indirectly related to size of the test arena. Periodicity of insect capture was determined using the time-stamp data that were recorded by the EGPIC system. Circadian rhythm was observed in the periodicity of the capture that corresponded to foraging activity peaks documented for sawtoothed grain beetles, with activity peaks occurring early in the scotophase. There were shifts in times of peak activity among the different test arena sizes that corresponded to differences in temperature in the grain mass. Increases in both temperature and contact between insects and grain probe in the smallest arenas resulted in higher capture of sawtoothed grain beetles. This research documents additional important factors when evaluating capture of sawtoothed grain beetles in grain probe traps.

The object of the study reported here was to establish the best behavioural bioassay to ascertain the responses of three representative species of stored-grain insect pests to potentially attractive odours. The insects tested were Oryzaephilus surinamensis, Sitophilus granarius and Cryptolestes ferrugineus. Following consideration of different types of behavioural bioassay, the Y-tube olfactometer and the pitfall bioassay were chosen for comparison. Both were tested with a representative substance known to be attractive to the test species: carob ( Ceratonia siliqua ) aeration extract in pentane, and a pentane control. A number of physical and biological factors were taken into account in order to ascertain the most efficient bioassay method while retaining similarity to the natural environment of the insects. The Y-tube olfactometer was used with these species for the first time and it gave good differentiation between test and control with O. surinamensis and S. granarius but not with C. ferrugineus. With the pitfall bioassay, the optimum conditions for screening potential attractants for all three species were 20°C and 50% relative humidity, with a bioassay duration of 1 h. Therefore, the optimum bioassay method for mixed sex adults of the three species tested was the pitfall bioassay. The increased response to the attractant with increased temperature (from 15°C to 20°C) shows that changing temperature may affect the insects’ responses.

Food-bait traps were used to study spatial and temporal distribution of the coleopteran fauna of the first floor of a feed mill in Central Italy. A total of 3396 beetles were captured during the 1-year survey. Beetles were most abundant during July and August and least abundant during February and March. Tribolium confusum du Val was the most abundant and widespread, followed by Oryzaephilus surinamensis (L.), Tribolium castaneum (Herbst), Attagenus brunneus Faldermann, Sitophilus oryzae (L.), and Stegobium paniceum (L.). The spatial patterns of annual catches of these six species were depicted by contour maps. In addition, high catches of O. surinamensis, T. castaneum and T. confusum, allowed construction of contour maps for monthly trap catches. The populations of A. brunneus were located in the bagging, milling, formulation and pelleting sites, and in the area around the conveyer belt. The highest populations of O. surinamensis were in the entry zone of the unloading pit and in the area around the conveyer belt with finished products. Sitophilus oryzae were present near the entry door of the unloading pit room, around the storage bins and in the storeroom. Populations of S. paniceum were found in the unloading pit as far as the conveyer belt and in a corner of storeroom. Tribolium castaneum was limited to a localized area in the room where raw material was processed and in the entry to the unloading pit room. The highest T. confusum populations were located in the milling, formulation and pelleting sites, and near balance and storage bins. Comparison of the spatio-temporal dynamics of these pests showed a segregation of populations, in both time and space, and a strong interaction among species is suggested. On the basis of our results, the spatial and temporal distributions are significantly affected by various factors, such as food availability, processing practices and temperature conditions in different areas.

Two known repellents of stored-product insects, DEET and neem, were compared to protein-enriched pea flour, defatted protein-enriched pea flour, and pea protein extract for their efficacy at reducing penetration and invasion by several common stored-product insects: Sitophilus oryzae (L.), Tribolium castaneum (Herbst) , Cryptolestes ferrugineus (Stephens), and Oryzaephilus surinamensis (L.). The methods of preparation of pea extract affected the penetration of S. oryzae . Protein-enriched pea flour, DEET and neem reduced the penetration of S. oryzae, but defatted protein-enriched pea flour and pea protein extract did not. The number of S. oryzae, T. castaneum, C. ferrugineus and O. surinamensis entering pierced paper envelopes that contained wheat and were treated with DEET was reduced by 99%, 86%, 97% and 91%, respectively. Neem was less effective than DEET in reducing penetration and invasion of insects. Protein-enriched pea flour did not prevent insects entering pierced envelopes.

The neogregarine, Mattesia oryzaephili (Neogregarinorida: Lipotrophidae) has only been reported from the sawtoothed grain beetle, Oryzaephilus surinamensis. The pathogen’s presence in cadavers of the rusty grain beetle, Cryptolestes ferrugineus, in collapsed colonies prompted studies of its potential to control stored-product insects. Respective mortality rates in fourth instar C. ferrugineus and C. pusillus were 15.3 and 17.7% at 10 2 oocysts/g of diet and 89.4 and 80.5% at 10 5 oocysts/g. The mortality of fourth instar O. surinamensis exposed to 10 5 oocysts/g was only 12%. For C. ferrugineus larvae, there were no significant differences in mortality and infection between exposure to Mattesia dispora and exposure to M. oryzaephili (P� /0.05), but for C. pusillus larvae, both responses were significantly higher for M. oryzaephili than M. dispora. Adult C. ferrugineus and O. surinamensis were similar in their responses to M. oryzaephili, with mortality not exceeding 20%, but differed in their responses to M. dispora, with O. surinamensis being more susceptible. The median lethal doses for larval Mediterranean flour moths, Ephestia kuehniella, were 7.9/10 7 M. oryzaephili oocysts/g of diet and 2.7/10 3 M. dispora oocysts/g of diet. In single dose assays of M. oryzaephili physiological host range, greater than 75% infection was achieved for Rhyzopertha dominica and Plodia interpunctella. More than half of oocysts germinated during passage through the guts of susceptible and resistant insects. Second and third instar Galleria mellonella were highly susceptible to M. oryzaephili infection, but fifth instars were not. Infection percentages in fifth instars exposed to 10 6 oocysts/g were significant only when boric acid or the stilbene, Blankophor † RHK were incorporated into the diet. Host range and general morphology confirm

This research used a model experimental system to explore the joint effects of resource fragmentation and resource deterioration on population dynamics. The system provides a rapid test of conservation theory and can aid in planning for large and expensive studies. The investigation subjected the sawtooth grain beetle, Oryzaephilus surinamensis (L.), to five experiments in which population abundance was monitored over time. Metapopulations were created by connecting adjacent vials of flour with rubber tubes. The metapopulations were arranged in rings, and food was replenished at two-week intervals. The experiments examined populations in (1) habitats becoming increasingly fragmented, (2) dynamically fragmenting structure with concurrent loss of resources over time, (3) static structure, dynamic resource loss and differing numbers of patches, (4) static structural arrangements with dynamic resource loss that mimic resource deterioration and destruction, and (5) static arrangements of connected fragments with an equal total amount of food in a few large patches or several small patches. Time series of stage-specific abundances were compared in repeated-measures ANOVA. The results show that populations respond in nonlinear ways to both the amount of food and area provided. Within a confined area, when food is plentiful, individual interaction limits population abundance. When the amount of food is reduced, population abundance becomes food dependent. Immediate increase in immature abundance was a characteristic of fragmentation while a delayed reduction of adults was characteristic of food reduction. The stage-specific interaction at intermediate food levels shows birth and death processes that control this system, and elucidates the relationship between area and food that is integral to the dynamics of patchy populations.

The efficacy of bifenthrin (0.5 mg/kg) + piperonyl butoxide (7 mg/kg) + chlorpyrifosmethyl (10 mg/kg) against beetle and psocid pests of sorghum was evaluated in silo-scale trials in southeast Queensland, Australia. The pyrethroid bifenthrin was evaluated as a potential new protectant in combination with the organophosphate chlorpyrifos-methyl, which is already registered for control of several insect pests of stored cereals. Sorghum (approximately 200 metric tons) was treated after both the 1999 and 2000 harvests and sampled at intervals to assess treatment efficacy and residue decline during up to 7 mo of storage. Generally, test strains of the beetles Rhyzopertha dominica (F.), Tribolium castaneum (Herbst), Oryzaephilus surinamensis (L), and Cryptolestes ferrugineus (Stephens) were prevented from producing live progeny for up to 7 mo. The treatment failed against one strain of R. dominica known to be resistant to bioresmethrin and organophosphates. Two malathion-resistant strains of O. surinamensis were marginally controlled with 94-100% fewer adult progeny produced. For psocids, no strains of Liposcelis bostrychophila Badonnel, Liposcelis decolor (Pearman), or Liposcelis paeta Pearman produced live progeny, although the control of a field strain of Liposcelis entomophila (Enderlein) was generally poor. Results show that this treatment should protect sorghum for at least 7 mo against most prevalent strains of grain insect in eastern Australia, although control may be limited in areas in which L. entomophila or pyrethroid-resistant R. dominica are present.

The behavioral response of the sawtoothed grain beetle, Oryzaephilus surinamensis (L.), to moisture gradients has been studied in some detail, but the effect of carbon dioxide (CO2), alone and in combination with low humidity, has never been reported. The effect of CO2 is of some interest because CO2 levels in stored grain are often elevated well above normal atmospheric levels by the metabolism of insects, fungi, and the grain itself. Also, CO2 is sometimes applied to bulk grain to control stored-product insects. The response of adult male O. surinamensis to humidity alternatives of 60 or 100% RH was determined in 2-way choice chambers after various treatments. Beetles removed from laboratory cultures and held at 60% RH with food for 4 h showed a strong avoidance of the higher humidity (hygronegative response). Beetles held without food in a dry atmosphere (

This study forms part of an effort to eliminate the need for fumigation with methyl bromide to control insect infestations in stored cocoa beans, through development of novel alternative vacuum-hermetic technology. In this communication, the effects of low pressures and exposure time were studied on the mortality of insects at a temperature of 18°C, chosen to simulate cocoa bean storage conditions in temperate climates. Three insect species were used, two of which are major pests of cocoa beans in producer countries, Ephestia cautella (Walker), and Tribolium castaneum (Herbst), while the third, Oryzaephilus surinamensis (L.), is a potential storage pest in temperate climates. For T. castaneum and E. cautella the egg stage was the most resistant to 55±10 mm Hg at 18°C, the times needed to obtain 99% egg mortality were 96 and 149 h, respectively. For O. surinamensis , the adult stage was the most resistant with 164 h being required to obtain 99% mortality.

Studies were conducted in three flat storerooms in Southern Greece, filled with approx. 45 tons of wheat each, stored in 1.5 m deep bulks, in order to examine the seasonal abundance of insect and mite species, in relation to their horizontal and vertical spatial distribution into the bulked grain. For this purpose, wheat samples were taken from June 2000 until March 2001, at 10-day intervals, by using a partitioned grain trier. The surface of the grain bulk was divided into three sampling zones, the central zone (the central part of the bulk), the edge zone (close to the walls) and the corners (the corners of the store rooms). The trier samples were examined separately for the upper, medial and lower 0.5 m of the bulk. Significant differences were recorded for wheat moisture content among zones (p

Twenty naturally occurring monoterpenoids were evaluated in a preliminary fumigation screening test on some important stored-product pest insects, including the rice weevil, Sitophilus oryzae , the red flour beetle, Tribolium castaneum , the sawtoothed grain beetle, Oryzaephilus surinamensis , the house fly, Musca domestica , and the German cockroach, Blattella germanica . Cineole, l -fenchone, and pulegone at 50 μg/ml air caused 100% mortality in all five species tested. Ketone compounds were generally more toxic than other monoterpenoids. Three monoterpenoids, the ketones pulegone, l -fenchone, and the aldehyde perillaldehyde, were selected for further study. They were effective against T. castaneum in the fumigation assay; however the toxicity was relatively low in comparison to dichlorvos. LC 50 values of these three monoterpenoids tended to decrease at longer exposure times and higher temperatures. Inclusion of either maize kernels or house fly medium (HFM) increased LC 50 values, HFM more so than maize kernels. Monoterpenoids may be suitable as fumigants or vapor-phase insecticides because of their high volatility, fumigation efficacy, and their safety.

Susceptibility to two storage insect pests [(Cryptolestes pusillus (Sch . onherr) and Oryzaephilus surinamensis (L.)] of eight commercial oat cultivars from the United States was determined in laboratory studies. Duration of insect development was shorter and number of progeny produced was greater on cracked than on whole oats. Simulations based on data from the study showed that insect populations would reach the threshold level for treatment in 2–3 months of storage at 301C on cracked oats. Insect population development was slowest on the hulless cultivar Paul when the oat kernels were cracked. Simulations also indicated that all cultivars of whole oats tested could be stored for at least 1 yr at 301C without reaching the threshold for treatment when infested with these two species of insects, and insect populations would decrease over time on the cultivars Don, Jerry, Milton, NewDak, Otana, and Valley. Analyses of oat grain quality characteristics, including kernel weight, groat hardness, and groat composition, provided little insight into the mechanism of observed differences in insect development among cultivars. Hardness of the kernels (as indicated by % broken groats after dehulling) may be related to near immunity to these two species of insects in whole Otana. Steaming whole oats to inactivate hydrolytic enzymes in the trichomes of the pericarp did not increase susceptibility to these two species of insects, suggesting that enzymes in the trichomes were not responsible for insect population development being slower on whole oats than on cracked oats. Although we were unable to identify the factors that determined relative susceptibility in this study, the results will be useful for selecting commercial oat cultivars for planting that will be less susceptible to insect pests in storage and suggest that the economics of

WOS: 000178737500007, Although high concentrations of zinc and manganese were found in mandibles of insect larvae that bore into seeds, these metals were not detected in mandibles of insect larvae that attack previously damaged seeds. Metals were present in the larval mandibles of a lepidopteran, the Angoumois grain moth (Sitotroga cerealella), and eight coleopterans, the lesser grain borer (Rhyzopertha dominica), cigarette beetle (Lasioderma serricorne), drugstore beetle (Stegobium paniceum), spider beetle (Gibbium aequinoctiale), warehouse beetle (Trogoderma variabile), cadelle (Tenebroides mauritanicus), larger black flour beetle (Cynaeus angustus), and cowpea weevil (Callosobruchus maculatus). Larvae of these species can chew into seeds. Larvae of six other coleopterans, the varied carpet beetle (Anthrenus verbasci), sawtoothed grain beetle (Oryzaephilus surinamensis), rusty grain beetle (Cryptolestes ferrugineus), red flour beetle (Tribolium castaneum), longheaded flour beetle (Latheticus oryzae), and granary weevil (Sitophilus granarius) have little if any ability to chew into seeds, and did not have metal in their mandibles. Larvae of the granary weevil hatch and feed within seeds that were penetrated previously during egg deposition by adults. However, newly hatched larvae of the cowpea weevil and the Angoumois grain moth have to bore through the seed coat before they begin feeding, and they have mandibles with high concentrations of zinc. These data support the hypothesis that deposition of zinc and/or manganese in larval mandibles enhances the larva's ability to penetrate seeds. Published by Elsevier Science Ltd.

Recent reports of the biocontrolpotential of the mite species Acarophenaxlacunatus (Cross & Krantz) (Prostigmata:Acarophenacidae) and the lack of biologicalstudies on this regulatory agent led to thepresent study carried out under laboratoryconditions. The objective of the investigationwas to assess the host range of A. lacunatus,so far only reported as egg parasite ofRhyzopertha dominica (F.) (Coleoptera:Bostrichidae). Four Coleoptera species ofstored cereals were used: R. dominica,Tribolium castaneum (Herbst) (Tenebrionidae),Cryptolestes ferrugineus (Stephens)(Laemophloeidae) and Oryzaephilus surinamensis (L.) (Cucujidae). The highest rates of eggparasitism were observed on R. dominica and T.castaneum, leading to a significant decrease ofpopulations of both species and reduced wheatweight loss. A. lacunatus was also able toparasitize eggs of C. ferrugineus, but not ofO. surinamensis. These results indicate abroader host range of A. lacunatus thaninitially suspected and also strengthen itspossibility of use in integrated pestmanagement programs in storage environments.

The potential of Acarophenax lacunatus (Cross and Krantz) (Prostigmata: Acarophenacidae) as a biological control agent of Rhyzopertha dominica (F.) and the lack of information on the host range of this mite species led to the present investigation carried out in laboratory conditions. Petri dish arenas divided into four regions, each containing five potential host eggs [Dinoderus minutus (F.), Oryzaephilus surinamensis (L.), R. dominica and Tribolium castaneum (Herbst)], were used in the study. A single physogastric female mite was released in the centre of each arena and its progeny preference for each potential host species was recorded. There was a significant influence of time on the parasitism rate and there was no egg parasitism of O. surinamensis by A. lacunatus. In no-choice tests, female mites showed higher egg parasitism on R. dominica and D. minutus than on T. castaneum. In addition, female mites also showed significantly greater preference for R. dominica, followed by D. minutus, than for T. castaneum in free-choice tests. These results suggest a broader host range of A. lacunatus than initially suspected and favour the possibility of its use as a biological control agent in integrated pest management programs in storage units.

Alive individual adult sawtoothed grain beetle Oryzaephilus surinamensis (Linnaeus, 1758) was discovered inside a nest mound of the red wood ant Formica rufa Linnaeus, 1758 during a survey of myrmecophilous invertebrates. The sawtoothed grain beetle is a widespread indoor pest that has not previously been found in an ant nest. It is one of the most common pests in stored grain and cereal products, but the natural life-style of the species is not known. As the site of discovery was exceptional, we verified the species identification using the DNA barcode. If the sawtoothed grain beetle can live in mounds of red wood ants, the mounds may become widespread source habitats for the future infestations of this serious stored product pest.

Acetylcholinesterase and carboxylesterase activities of four strains of Oryzaephilus surinamensis (L.) larvae were examined. The three strains of VOS49, VOSF, and VOSCM were resistant to malathion, fenitrothion, and chlorpyrifos-methyl, respectively, while VOS48 was a susceptible strain. Cross-resistance to all three organophosphate insecticides tested was confirmed in larvae of the three resistant strains. Acetylcholinesterase activity was not correlated to organophosphate resistance in those resistant strains. VOS49, VOSF and VOSCM showed enhanced levels of carboxylesterase activity based on p -nitrophenyl acetate, α -naphthyl acetate, or β-naphthyl acetate substrates. However, these activities were significantly lower than those of O. surinamensis adults. PAGE zymograms showed major differences in carboxylesterase band pattern among strains. VOS49 carboxylesterase banding pattern was significantly different from other two resistant strains. Interestingly, these larval esterase band patterns were very similar to those of O. surinamensis adults. Therefore, carboxylesterase activity of O. surinamensis plays important role in resistance to organophosphate insecticide from larval stage.

A machine vision method has been developed for the detection of adult beetles, rodent droppings and ergot in harvested wheat. Samples were presented as a monolayer of around 25 generally non-touching but randomly oriented objects. Detection rates for artificially prepared samples ranged from 87% for ergot to 100% for adult Oryzaephilus surinamensis (saw-toothed grain beetle). When applied to two commercial samples containing several insect species, detection rates were 89 and 96%. The rate of false positives arising from samples of wheat containing permitted admixture-only was low. The speed of the integrated algorithm package for detection of all three contaminant types approaches that required to scan 3 kg grain in just 3 min (the throughput required by the UK trade).

The fumigant toxicities of lavender and ylang-ylang essential oils were tested against a chlorpyrifos-methyl resistant strain (QVOS102) and an insecticide-susceptible reference strain (VOS48) of the saw-toothed grain beetle, Oryzaephilus surinamensis L. (Coleoptera: Silvanidae). The resistant strain showed 1.3- and 1.6-fold higher tolerance against lavender and ylang-ylang fumigation toxicity, respectively, relative to the susceptible strain. LT50 values calculated as the time to attain 50% mortality of tested insects during fumigation were determined at two different concentrations. At 15 μl/l of air, QVOS102 had 2.9- and 1.4-fold higher LT50 values for lavender and ylang-ylang fumigation toxicity, respectively, than VOS48. At 200 μl/l air, QVOS102 had 6.4- and 2.9-fold higher LT50 values for lavender and ylang-ylang fumigation toxicity, respectively, than VOS48. Piperonyl butoxide, a potential inhibitor of cytochrome P450-dependent monooxygenase, increased fumigant toxicities of the two essential oils against QVOS102. The enhanced tolerance for the essential oil may have resulted from the enhancement of detoxifying enzymes associated with insecticide resistance.

This review summarises the published information on the behaviour of beetles in grain bulks that could lead to the identification of additional factors with the potential for enhancing existing lures or developing new ones. The review concentrates mainly on the adult stage of the five beetle pest species Oryzaephilus surinamensis (L.) , Sitophilus granarius (L.), Cryptolestes ferrugineus (Stephens), Typhaea stercorea (L.) and Ahasverus advena (Waltl) . After an analysis of the grain store environment and the origins of storage pests, particular attention is paid to behaviour associated with beetle movement and distribution within grain bulks, and their response to food and other multi-species attractants. Potential sources of new semiochemicals are identified; as well as the grains themselves, these include attractive volatiles associated with hot spots in grain, mouldy grain, and alternative insect pest habitats such as mammals’ and birds’ nests. It might also be worth looking for new semiochemicals produced during the mass upward movements of beetles from grain often seen following disturbance, although these could be repellents rather than attractants. Other sources of repellent semiochemicals with potential as grain protectants could be predatory and parasitic species of insects. Consideration is given to behavioural influences that may conflict with the intended response to attractive lures; for example, the presence of damaged grains, moisture and temperature gradients in the grain bulk may act as rival attractants, while many species prefer to hide away from bright light. As population densities rise, inter- and intra-specific competition becomes increasingly important. Human activities associated with grain handling, drying, cooling and pest control, as well as the presence of natural enemies and pathogens, all have the potential to affect insect response to a lure. Opportunities for the development of more effective lures are highlighted.

We studied the occurrence of (TTAGG) n telomere repeats in 12 species of beetles, representing main lineages of the Coleoptera phylogenetic tree, by Southern hybridization and fluorescence in situ hybridization (FISH). In contrast to other insect orders, beetles were heterogeneous with respect to the occurrence of TTAGG repeats. In addition, the presence or absence of (TTAGG) n motif was irrespective of phylogenetic relationships. In the suborder Polyphaga, six species displayed positive hybridization signals. These were Silpha obscura, Agrilus viridis, Ampedus sanguineus, Stegobium paniceum, Oryzaephilus surinamensis, and Leptinotarsa decemlineata. Whereas negative signals were obtained in three polyphagan species, Geotrupes stercorarius, Thanasimus formicarius, and Sitophilus granarius. In the suborder Adephaga, the TTAGG sequence was present in one species, Graphoderus cinereus, and absent in two species, Orectochilus villosus and Pterostichus oblongopunctatus. We concluded that the telomerase-dependent (TTAGG) n motif had been repeatedly lost in different phylogenetic branches of Coleoptera and probably replaced with another mechanism of telomere elongation. This had to happen at least 5–6 times. The results suggest a predisposition or a backup mechanism of telomere maintenance in the genome of beetles that enabled them to make frequent evolutionary changes in the telomere composition.

One strategy that has been used to find germplasm for developing improved plant varieties is to test ancestral germplasm for the desired traits. Although the progenitors of commercial maize are not known, a hybrid (called Tripsacorn) developed from a perennial teosinte, Zea diploperennis, and eastern gamagrass, Tripsacum dactyloides, resembles the earliest known samples of primitive domesticated maize. We tested resistance of whole Tripsacorn to the primary storage pest (primary storage pests can infest intact kernels) the maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), and resistance of ground Tripsacorn to the secondary storage pest (secondary pests usually cannot infest intact kernels) the sawtoothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). Tripsacorn was immune to attack by S. zeamais. The weevils were unable to lay eggs in the Tripsacorn, and we hypothesized that the hardness of the fruitcase was responsible for lack of weevil oviposition. Oryzaephilus surinamensis were able to complete immature development on ground Tripsacorn, but duration of development was longer and weight of emerged adults was less than for beetles developing on wheat. Hardness of the fruitcase may have been a primitive mechanism of defense against insects and other pests, but probably would not be an acceptable trait in commercial varieties. It remains to be determined whether the possible antibiotic effect demonstrated in ground Tripsacorn would be a useful trait in commercial maize hybrids.

This study is conducted to determine the effect of pathogenicity of the fungus Lecanicillium lecanii in some aspects of life of the insect saw toothed beetle Oryzaephilus surinamensis L. (Coleoptera: Silvanidae) under laboratory conditions with three concentrations of spores and mildew commentator (1 × 103, 1 × 105, 1 × 107) spore / ml , on eggs and larvae second phase of the insect .The study also includs the effect of the fungus concentrations of germination on rice (jasmine) by using direct spray treatment. The results show great fungus efficiency in the control of some aspects of life of the insect, where varied efficiency depends on the concentration of spores, The highest percentage loss of eggs is 63.33% at a concentration of 1 × 107 spore / m followed by aconcentration of 1 × 105 spore / ml in which the loss is 60 % , while the 50% was at a concentration of 1 × 103 spore / ml, which them decreased to 3.33% at the control treatment .The highest rate of destruction of the larvae of the second phase was 60% at a concentration of 1 × 103 spore / ml , and decreased to 56.66% and 46.66% at concentrations 1 × 107 and 1 × 105 spore / ml respectively. In addition there were no significant differences in germination rates for grain treatment direct spray concentrations of innate commentator.

In laboratory experiments, toxicity of carbon dioxide and carbon dioxide - phosphine mixture was investigated against 4 species of stored-product insects. In empty-space trials, estimates of the median lethal doses of carbon dioxide against adults of Oryzaephilus surinamensis (L.), Lasioderma serricorne (F.) and eggs of Plodia interpunctella (Hǘbner) and Cadra cautella (Walker) were 7.67, 12.10, 5.76 and 7.25 mg/L, respectively. Penetration tests revealed that, carbon dioxide vapors could penetrate into the foodstuff mass and kill concealed insects in foodstuff spaces. Comparison of LD 50 values between empty-space tests and penetration experiments after 24 h exposure indicated that, the increase in penetration toxicity was 3.61, 2.90, 4.02 and 3.03-fold for O. surinamensis, L. serricorne, P. interpunctella and C. cautella , respectively. In the hidden infestation trials, the carbon dioxide-phophine mixture destroyed developmental stages of tested insects concealed inside the foodstuff spaces. These results to a complete control with CO2 – phosphine mixtures for 24 h and subsequently, observed during 7, 10 and 11 weeks after the exposure. It is concluded that, combination of carbon dioxide with reduced dose of phosphine could be considered as a viable alternative to methyl bromide under field conditions due to much wider margin of safety for operational personnel and substantiate fewer undesirable environmental side effects. Key words : Oryzeaphilus surinamensis, Indian meal moth, fumigation, bioassay.

Many populations of organisms deplete their resources, causing population growth rates to decline as population density increases. I used the sawtoothed grain beetle, Oryzaephilus surinamensis (L.), as a model to gain insight into the mechanisms of population regulation. Eight experiments differentiated the effects of crowding and food depletion on dispersal, mortality, and reproduction. Generally, food depletion caused increased mortality of immature beetles, sharply reduced oviposition, and increased adult dispersal. Rates of birth and death were both negative exponential functions of increasing density. The experiments quantify the trade-off between food and area in population regulation. These trade-offs varied with initial abundance of larvae and adults and show the risk of ignoring abundances of any life stages when characterizing vital rates. I contrast population regulation of O. surinamensis with Tribolium sp., and suggest O. surinamensis is a good alternative for experiments on population dynamics because of better mobility and shorter development time.

Phosphine fumigation trials were carried out on bag-stacks of paddy rice to study the differences in gas loss rates and concentration–time (Ct) products achieved during the treatment of indoor and outdoor stacks. Stacks (89–132 t) were fumigated singly under 250 μm thick polyethylene sheeting, which was sealed with a double layer of sand-snakes to the concrete floor. Phosphine was applied as an aluminium phosphide formulation and the fumigations continued for 7 days. In the first experiment, stacks of paddy rice with moisture contents ranging from 12.2 to 13.7% were held in either indoor or in outdoor storage and subjected to fumigation at the rate of 2, 3 or 4 g of phosphine/tonne. The outdoor stacks held relatively low levels of phosphine with Ct products for the indoor stacks of 135, 171 and 294 g h/m3, respectively, whilst the corresponding values for the outdoor stacks were 70, 85 and 166 g h/m3 only. The average gas loss rate was 14.5% per day for the indoor stacks and 29.5% for the outdoor stacks. In the second experiment, old stacks of paddy rice inside a godown, one each with grains at 8.8 and 9.8% moisture content, were fumigated at 3 g phosphine/tonne. Release of phosphine was delayed and fumigant sorption was less and therefore higher Ct products of 204 and 216 g h/m3 were achieved. In the stacks built outdoors, the resident infestations of Rhyzopertha dominica, Cryptolestes sp. and Oryzaephilus surinamensis were completely controlled despite lower Ct products. On the other hand, in the stacks of old paddy, R. dominica survived the treatment. Subsequent testing showed that the population had a degree of resistance to phosphine.

Cephalonomia tarsalis, an ectoparasitoid, and Beauveria bassiana, an entomopathogenic fungus, are potential biological control agents for the sawtoothed grain beetle, Oryzaephilus surinamensis. Several experiments were conducted to determine whether the two beneficial organisms are compatible. Wasps exhibited little avoidance behavior toward the fungus. Adult wasps oviposited on B. bassiana-infected larvae up to within 1 day of the host’s death and the appearance of red fungal pigment. Wasp larvae are susceptible to the fungus and die within 1 day of oviposition on host larvae with mycosis. A 3-h exposure of adult wasps to 100 mg of B. bassiana/kg of wheat resulted in 52.7% mortality. Nevertheless, the wasps entered into grain containing B. bassiana conidia as freely as they entered into conidia-free grain. The mean prevalence of B. bassiana in 46 samples of pooled wheat representing 276 locations was 7.5 colony-forming units/g of wheat. Natural C. tarsalis exposure to B. bassiana in untreated stored wheat is likely to be below lethal quantities, and the introduction of the fungus in insecticidal quantities would have a negative impact on C. tarsalis populations.

The efficacy of an atmosphere with a high content of carbon dioxide under a pressure of 5 and 10 bar against young eggs of Ephestia kuehniella Zeller (Lep.: Pyralidae) and adults of Stegobium paniceum (L.) (Col.: Anobiidae) and Oryzaephilus surinamensis (L.) (Col.: Cucujidae) was investigated. At a pressure level of 10 bar, a 100 % mortality in eggs of E. kuehniella was obtained after 4 hours. Complete control was not obtained with the adult beetles, except for a 2 hour-treatment at 10 bar with individuals of S. paniceum, which not were offered protection. It is demonstrated that when working with an atmosphere of carbon dioxide under pressure of 10 bar for 2 hours, even a slight protection from food material will influence the mortality. The reason for these findings are discussed.

Xylocoris flavipes (Reuter), the warehouse pirate bug, is a predator of many stored-products pests. This study compared the functional response of X. flavipes with different densities of the prey species Tribolium castaneum (Herbst), Oryzaephilus surinamensis (L.), Plodia interpunctella (Hubner), and Rhyzopertha dominica (F.) in two different habitats: empty glass jars and glass jars filled with wheat kernels that were designed to simulate more natural conditions in stored grain. Differences in the functional response of X. flavipes to all combinations of prey densities and grain conditions were compared with the predicted functional response curves from Holling’s type I and type II models, and to Hassell’s type III model. The functional response of X. flavipes was best described by Holling’s type II model, but a type III response occurred with prey that were more difficult to subdue, such as T. castaneum larvae. Numbers of prey attacked by females were greater than those attacked by males (P < 0...

The acetylcholinesterase, carboxylesterase, and cytochrome P450 monooxygenase activities of three strains of Oryzaephilus srinamensis (L.) were examined to better understand biochemical mechanisms of resistance. The three strains were VOS49 and VOSCM, selected for resistance to malathion and chlorpyrifos-methyl, respectively, and VOS48, a standard susceptible strain. Cross-resistance to malathion and chlorpyrifos-methyl was confirmed in VOS49 and VOSCM. Acetylcholinesterase activity was not correlated to resistance among these strains. VOS49 and VOSCM showed elevated levels of carboxylesterase activity based on p-nitrophenylacetate, alpha-naphthyl acetate, or beta-naphthyl acetate substrates. PAGE zymograms showed major differences in caboxylesterase isozyme banding among strains. VOSCM had one strongly staining isozyme band. A band having the same Rf-value was very faint in VOS48. The VOS49 carboxylesterase banding pattern was different from both VOSCM and VOS48. Cytochrome P450 monooxygenase activity was based on cytochrome P450 content, aldrin epoxidase activity, and oxidation of organophosphate insecticides, all elevated in resistant strains. The monooxygenase activity varied with insecticide substrate and resistant strain, suggesting specific cytochromes P450 may exist for different insecticides. The monooxygenase activity of the VOS49 strain was much higher with malathion than chlorpyrifos-methyl as substrates, whereas VOSCM monooxygenase activity was higher with malathion than chlorpyrifos-methyl as substrates. Results are discussed in the context of resistance mechanisms to organophosphate insecticides in O. surinamensis.

An Electronic Grain Probe Insect Counter system, which incorporates modified passive grain probes, allows offsite monitoring and detection of insect pests in stored grain. An electronic count is generated whenever an insect falls through an infrared beam in the sensor head located at the bottom of the electronic grain probe. We report descriptions and laboratory evaluations of prototype electronic grain probes that were custom-made in-house (n=8) and by small-scale manufacturing (n=54). Laboratory tests, in which dead insects were dropped through a probe, were conducted to determine if electronic probes accurately count the numbers of insects that are captured. Accuracy of the manufactured electronic probes increased as the size of the test insect increased from 93.6% for the smallest insect tested (Cryptolestes ferrugineus, the rusty grain beetle) to 99.5% for the largest (Tribolium castaneum, the red flour beetle). Custom-made probes were significantly more accurate for C. ferrugineus (96.5% versus 93.6%) but there was no difference in accuracies for the larger insects. Comparisons among all probes found that probe accuracy was correlated with variation in the magnitude of the output signal from the infrared phototransistor. Thus, use of diode/phototransistor pairs with a more consistent beam or with improved beam focus may further improve probe accuracy. Good performance was obtained with the manufactured electronic probes. Tests with live insects under field conditions are needed to further evaluate the system performance.

Diatomaceous earth (DE) is a desiccant insecticide and most efficacious in low humidity. It acts on insect cuticle by absorbing lipids, and perhaps by cuticular abrasion. Beauveria bassiana (Balsamo) Vuillemin, an entomopathogenic fungus, is most efficacious in high humidity and has a complex interaction with cuticular lipids. Interaction between these materials may enhance insect control performance. Assays with stored-grain beetles were conducted with B. bassiana at rates of 11, 33, 100, and 300 mg of conidia per kilogram of grain with and without single rates of DE that killed 10% or less of the target beetles. The assays revealed synergism in effects on adult Rhyzopertha dominica (F.) and Oryzaephilus surinamensis (L.) at all doses. There was statistically significant synergism for adult Cryptolestes ferrugineus (Stephens) and larval R. dominica but at only one B. bassiana rate for each target. Both amorphous silicon dioxide, a sorptive dust, and diamond dust, an abrasive, showed synergistic interaction with B. bassiana on adult R. dominica. These results may provide a basis for a least-toxic approach to control of stored-product beetles and for efficacy-enhancing formulation of entomopathogenic fungi.

The esterase properties of two highly chlorpyrifos-methyl-resistant strains of Oryzaephilus surinamensis differentially resistant to fenitrothion were investigated. Isoelectric focusing of whole insect homogenates revealed qualitative differences in the isozymes present, with differences in both the number of esterases with elevated activity in each strain and the ionic charge of these isozymes between strains. These esterases were concluded to be B-esterases, with no evidence of A-esterase activity in whole insect homogenates. Native polyacrylamide gel electrophoresis and isoelectric focusing also revealed qualitative differences between strains in the esterase with the greatest activity, purified using ion-exchange chromatography. These differences were thought to be configurational, with SDS-PAGE revealing no difference in the electrophoretic mobility of the two esterase bands, each having a molecular weight of 71 kDa. There was also no difference found in the sequence of the first 15 N-terminal amino acids. Inhibition assays of the purified enzyme samples using the specific insecticidal inhibitors of chlorpyrifos oxon and fenitrooxon revealed that the esterases from these strains were highly sensitive to inhibition by chlorpyrifos-methyl oxon and significantly less sensitive to inhibition by fenitrooxon. The enzyme sample from insects of MH130f was found to be 247 times less sensitive to fenitrooxon than chlorpyrifos-methyl oxon inhibition. The esterase sample from insects of strain HH012f, highly resistant to both insecticides, was 21 times more sensitive to fenitrooxon inhibition than the sample from MH130f, with intermediate fenitrothion resistance. Differences in the qualitative esterase properties of these strains were proposed as an explanation of the differences in fenitrothion sensitivity and resistance.

Esterase activity in 16 strains of Oryzaephilus surinamensis (L.) with different degrees of resistance to chlorpyrifos-methyl and fenitrothion were investigated quantitatively and qualitatively. Chlorpyrifos-methyl resistance strongly and positively correlated with total esterase activity, whereas there was a moderate relationship between fenitrothion resistance and esterase activity. Polyacrylamide gel electrophoresis (PAGE) provided visual confirmation of these relationships and identified qualitative differences in esterase activity between the two highly chlorpyrifos-methyl strains. Both methods revealed that the elevated esterase activity was not acetylcholinesterase based. The involvement of elevated esterase activity in resistance was confirmed through its inhibition by chlorpyrifos and chlorpyrifos oxon. PAGE was identified as an effective tool for the simple and rapid detection of resistance due to the activity of esterases and is more powerful than quantitative total esterase assays due to its ability to identify both quantitative and qualitative differences.

The cause for the deterioration of quality in phane, the edible larva of the emperor moth, Imbrasia belina (Westwood) was investigated. Samples were subjected to bacteriological and mycological analyses. In addition insect pests which affect storage life of the product were also assessed. 70% of the bacterial isolates associated with phane were proteolytic and 75% were either chitinolytic, lipolytic or both. Most isolates were sporeformers. But, other Gram-positive and negative isolates were also present in significant numbers. The most frequent fungal isolates were species of Aspergillus, Penicillium, Fusarium, Cladosporium and phycomycetes. Some of the fungal isolates are known to be mycotoxin producers. The insect which were associated with phane were Dermestes maculatus, Sitophilus zeamais, Corcyra cephalonica, Tribolium confusum, Tribolium casteneum, Oryzaephilus surinamensis, Bracon hebetor, Anisopteromalus cavandrae, and Stathmopoda species. Mites were also found infesting stored phane. The postharvest deterioration of phane appeared to be a concerted effort by the bacteria, moulds and insects.

The fumigant toxicities of eucalyptus essential oil and 1,8-cineole, the major component of eucalyptus oil, were tested against a chlorpyrifos-methyl resistant strain and a reference strain of the sawtoothed grain beetle, Oryzaephilus surinamensis (L.). The resistant strain showed 1.9- and 2.2-fold higher tolerance against essential oil and 1,8-cineole fumigation toxicity, respectively, relative to the susceptible strain. The increased tolerance for the essential oil may be the result of cross-resistance. The resistance mechanisms in the resistant strain are discussed in relation to elevated detoxifying enzymes such as cytochrome P450 and esterases.

Esterases from a fenitrothion-resistant strain (VOSF) of the saw-toothed grain beetle, Oryzaephilus surinamensis (L.), are presumed to play a role in conferring resistance to malathion, fenitrothion, and chlorpyrifos-methyl. Colorimetric assays showed a significant positive correlation between increased resistance to fenitrothion in strains of O. surinamensis examined and elevated esterase hydrolytic activity to substrates of p-nitrophenyl acetate, alpha-naphthyl acetate, and beta-naphthyl acetate. Esterase zymograms showed different banding patterns between VOSF and an insecticide-susceptible strain, VOS48. A major esterase in the VOSF strain, not detected in VOS48, was purified and characterized by chromatographic and electrophoretic techniques. On the basis of SDS-polyacrylamide gel eletrophoresis, the molecular mass of the purified esterase from VOSF was 130 kDa and consisted of two 65 kDa subunits. Additional properties of this enzyme are discussed.

Data on population growth rates for four insect species were used to develop prediction models of populations in grain stores. The form of the model was based on an existing insect model from the literature. The species chosen (Rhyzopertha dominica, Sitophilus oryzae, Oryzaephilus surinamensis and Tribolium castaneum) represent common Australian grain storage pests. The resulting models were incorporated into a one-dimensional drying and aeration simulation program, and plots of predicted populations at different levels during drying and aeration were obtained. The model was found to predict growth rates under tropical conditions in good agreement with laboratory data. Agreement was poorest at low temperatures and for Sitophilus oryzae only, at low relative humidities. The model consistently explained about 95% of the variance in the data for each species. Psychrometric plots of the data and model are presented.