Biomonitoring of agriculturally important insects is increasingly vital given our need to understand: (a) the severity of impacts by pests and pathogens on crop yield and health and (b) the impact of environmental change and land management on insects, in line with sustainable development and global conservation targets. Traditional entomological traps remain an important part of the biomonitoring toolbox, but sample processing is laborious and introduces latency, and accuracy can be variable. The integration of molecular techniques such as environmental DNA and DNA metabarcoding into insect biomonitoring has gained increasing attention, but the advantages of doing so, the kind of data this can generate, and how easily and effectively molecular analyses can be integrated with the diverse types of entomological traps currently used remains relatively unclear. In this review, we examine how combining DNA metabarcoding with a range of conventional and unconventional entomological sampling techniques can advance biomonitoring in a way that is useful to researchers and practitioners. We highlight some of the key challenges and how to mitigate them, using examples of its integration with different sampling methods from the literature (e.g., interception, pitfall and sticky traps) to demonstrate efficacy and suitability. We discuss how metabarcoding data can be used to infer ecological networks, emphasizing the importance of this as a framework for understanding species interactions and ecosystem functioning for more effective and descriptive biomonitoring. Finally, future advances in biomonitoring are highlighted, alongside recommendations of best practice for researchers both new to and experienced in invertebrate biomonitoring with metabarcoding.

The aphid‐transmitted viruses Potato virus Y (PVY) and Potato virus A (PVA) commonly affect seed potatoes in the UK. The transmission efficiency for aphid species is used to calculate a potential transmission risk and is expressed as a relative efficiency factor (REF). These REFs have not previously been calculated for UK strains of viruses or aphid clones. Using a previously published method, REFs have been calculated for the aphid species and viruses commonly occurring in UK potatoes. The efficiency of transmission of Myzus persicae is nominally set to a REF of 1 and REFs for other species are calculated relative to this. These data represent the first set of REFs calculated for PVA transmission. Macrosiphum euphorbiae (REF 0.91) was almost as efficient as M. persicae at PVA transmission. The data were further analysed to compare transmission rates of PVY and PVA using a binomial (logit) generalized mixed model to take into account the potential influence of variation in virus titre between leaves. This approach found that there is little variation between the efficiency of transmission between clones of each aphid species or between strains within a virus species. This is a first report that Aphis fabae, Metopolophium dirhodum, Sitobion avenae, Acyrthosiphon pisum and Cavariella aegopodii have the ability to vector PVA. This study also represents a first report that C. aegopodii has the ability to vector PVY and confirms the potential of S. avenae, A. fabae, M. euphorbiae and Rhopalosiphum padi as important PVY vectors.

The effects of CB1 antagonist/inverse agonists on the acquisition and consolidation of conditioned fear remain uncertain. Recent studies suggest that the CB1 antagonist/inverse agonist AM251 affects acquisition or consolidation of both contextual and discretely cued fear memories. AM251 is frequently referred to as a CB1 antagonist; however in vitro signal transduction assays indicate that this drug also elicits inverse agonist activity at CB1 receptors. The present studies were undertaken to compare the effects of AM251 on conditioned fear with those produced by AM4113, a novel CB1 antagonist with minimal inverse agonist activity. All drugs were administered prior to conditioning. In retention tests conducted two weeks after conditioning, both AM251 (4.0 mg/kg) and AM4113 (6.0 mg/kg)-treated animals exhibited reduced freezing during a conditioned tone cue played within a novel context. In contextual fear retention tests, animals previously treated with 4.0 or 8.0 mg/kg AM251 exhibited enhanced freezing. By contrast, no dose of AM4113 had any significant effect on contextual fear memory, which is consistent with the lower signal transduction activity of AM4113 at CB1 receptors compared to AM251. These results suggest that CB1 neutral antagonists may be less likely than CB1 inverse agonists to facilitate the acquisition or consolidation of contextual fear that may contribute to some clinical disorders.

Cannabinoid CB1 inverse agonists suppress food-motivated behaviors, but may also induce psychiatric effects such as depression and anxiety. To evaluate behaviors potentially related to anxiety, the present experiments assessed the CB1 inverse agonist AM251 (2.0–8.0 mg/kg), the CB1 antagonist AM4113 (3.0–12.0 mg/kg), and the benzodiazepine inverse agonist FG-7142 (10.0–20.0 mg/kg), using the open field test and the elevated plus maze. Although all three drugs affected open field behavior, these effects were largely due to actions on locomotion. In the elevated plus maze, FG-7142 and AM251 both produced anxiogenic effects. FG-7142 and AM251 also significantly increased c-Fos activity in the amygdala and nucleus accumbens shell. In contrast, AM4113 failed to affect performance in the plus maze, and did not induce c-Fos immunoreactivity. The weak effects of AM4113 are consistent with biochemical data showing that AM4113 induces little or no intrinsic cellular activity. This research may lead to the development of novel appetite suppressants with reduced anxiogenic effects.

Drugs that interfere with cannabinoid CB1 transmission suppress food-motivated behaviors and may be useful as appetite suppressants, but there is uncertainty about the locus of action for the feeding-suppression effects of these drugs.

This study was carried out primarily to ascertain whether the movement of Oryzaephilus surinamensis and Sitophilus granarius from low to high humidity zones occurs in bins of wheat and whether aeration of the grain (10m3/h/t) affects this movement. The second aim was to ascertain the best placement of insect detection traps under the different conditions. Insects were introduced into the lower half of the grain in the bins and their movement was monitored using traps placed at various depths in the grain. Sitophilus granarius did not move through the grain into the top layer regardless of the moisture content, temperature or aeration status of the grain. More O. surinamensis were caught in unventilated bins than in ventilated bins. More insects were caught in the ventilated bins containing layers of both dry and wet grain than in the bins containing only dry grain. The spatio-temporal distribution of O. surinamensis varied significantly. The depth at which insects were trapped varied between treatments: in ventilated dry grain, most insects were trapped at the surface; in ventilated wet and dry grain, most insects were trapped at 10cm and 0.75m; in unventilated wet and dry grain, the vast majority of the insects were trapped at 0.75m. Very few insects were trapped at 1.75m regardless of the treatment. The proportions of the initial population of O. surinamensis which were recaptured in the top layer of grain varied between treatments. Most were recaptured in the unventilated bins containing wet and dry grain followed by ventilated bins containing wet and dry grain. The smallest proportion of the population was recaptured in the ventilated bins containing only dry grain. Immediate practical implications for pest monitoring based on physical control measures in use are discussed.

"Maintaining Aethina tumida (Coleoptera: Nitidulidae) under quarantine laboratory conditions in the UK and preliminary observations on its behaviour." Journal of Apicultural Research, 47(3), pp. 192–193

Commodities may be attacked by a multitude of pest species simultaneously and so to be cost-effective any hire must be attractive to a range of target species. The objective of this study was to test a multi-species lure formulation with different dispensers under conditions as close as possible to their use in practice. The attractant effect of the multi-species lure formulation was tested using two types of dispensers with populations of the three principal grain beetle pests in the UK (Oryzaephilus surinamensis, Sitophilus granarius and Cryptolestes ferrugineus). The trials were performed over a period of six weeks with the lures tested in PC(TM) Traps: first in a grain bulk and in six grain bins and second in the surrounding area using PC(TM) Floor Traps. The amounts of volatiles released in and around ill situ traps were measured using Solid-Phase Microextraction (SPME).The first lure dispenser tested was attractive to O. surinamensis and C ferrugineus but it attracted fewer S. granarius than the control traps. It was shown that most of the volatiles were released at the beginning of the trial and therefore lures were not effective over the whole six-week period. The second lure dispenser released the attractant volatiles more consistently over six weeks and exerted significant. attraction to O. surinamensis and C ferrugineus in PC(TM) Traps in the grain bulk and to O. surinamensis and S. granarius in floor traps. Too few C ferrugineus were caught in floor traps to make a comparison. The reason for the repellent effect on S. granarius in the grain bulk was unclear and this is discussed along with the importance of measuring volatiles released by the lure. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.

The objective of this study was to identify the attractive components of a carob–peanut extract which is known to be attractive to the three principal grain beetle pests in the UK (Oryzaephilus surinamensis, Sitophilus granarius and Cryptolestes ferrugineus). Coupled GC-EAG was used to determine which components in the extract elicited an EAG response. The total number of GC peaks, which elicited an EAG response from O. surinamensis, S. granarius and C. ferrugineus was four, 10 and 12, respectively. The components responsible for these peaks were identified by GC-MS and the compounds tested for a behavioural response in pitfall bioassays along with some other potential attractants, identified from a literature review. Oryzaephilus surinamensis, S. granarius and C. ferrugineus responded in bioassays to six, five and nine compounds, respectively. Two compounds (E-2-nonenal and 4-ethylacetophenone) elicited a positive behavioural response from all three species and three compounds (2-phenylethanol, hexanoic acid and E-3-octen-2-one) elicited a response from two of the species. This work has identified a number of compounds, which could form the basis for the formulation of a multi-species lure for the three principal grain beetle pests in the UK.

By using food-bait traps, we evaluated the presence and the spatio-temporal distribution of insect pests in an industrial semolina-mill, with particular attention to Tribolium confusum du Val in which the spatio-temporal dynamics of females and males were also studied separately. A total of 1401 insect specimens was captured in the traps, belonging to 14 taxa, mainly Coleoptera. The most abundant species were T. confusum (with 1002 adults), followed by Typhaea stercorea (L.) (with 158 adults) and T. castaneum (Herbst) (with 110 adults). Of particular interest was the presence in the food-bait traps of T. confusum and T. castaneum adults in a mixed population with equal numbers of males and females. Furthermore, analysis of the spatio-temporal dynamics suggested that the distribution of the two sexes in T. confusum was almost the same during the entire sampling period. The findings of our study can usefully be applied to the management of Tribolium infestations, but further and more detailed studies are needed to better understand the ecology and behaviour of the species in association with searching for food and production of aggregation pheromones.

Foodstuffs give rise to complex volatile profiles which may consist of several hundred components. Determination of the key components that elicit specific insect behaviour enables simplification of constituents for incorporation into attractive lures. Progress towards an attractive lure to improve detection of the foreign grain beetle, Ahasverus advena has been considerably aided by the application of a sequence of different techniques. Coupled gas chromatography–electroantennogram has shown that this species responds to just two components from a complex mixture derived from pods of the carob tree, Ceratonia siliqua (L.). These components were identified by gas chromatography–mass spectrometry as 2-nonanone and 2-undecanone. At the amounts found in the extract, these two components gave 41% and 62%, respectively, of the electroantennogram activity of the whole extract. Behavioural bioassays using pitfall tests showed that each component was as attractive as the whole carob extract. These behavioural results were confirmed by use of a straight-tube olfactometer which proved a useful alternative to the pitfall test for this species. This study represents an important step towards the development of simple and effective lures for storage insect pests based on naturally occurring food attractants.

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 1h. 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.

The Home-Grown Cereals Authority (HGCA) has provided funding for this project but has not conducted the research or written this report. While the authors have worked on the best information available to them, neither HGCA nor the authors shall in any event be liable for any loss, damage or injury howsoever suffered directly or indirectly in relation to the report or the research on which it is based.

Monitoring insects in stored products is essential for the efficient application of control strategies, be they chemical, physical, biological or integrated. The Pitfall Cone (PC) trap was invented and developed in the UK to monitor crawling insect pests within stored grain. The PC trap has proven to be an effective insect monitor for the primary pests of stored grain in the United Kingdom, including Sitophilus granarius (the grain weevil), Oryzaephilus surinamensis (the saw-toothed grain beetle) and Cryptolestes ferrugineus (the rust-red grain beetle). The CSL I-SPy Insect Indicator (PC Floor Trap) is a further development of the PC trap for use on flat surfaces in food and stored commodity premises. It does not rely on a sticky surface to trap insects, allowing it to be effective even in dusty environments such as flour mills. In a previous laboratory comparison with four other insect monitoring devices, the CSL I-SPy Insect Indicator has proved to be effective at trapping all six insect pest species tested. The work reported here investigates the effectiveness of this new trap, with an improved attractant lure, against the same six species and compares it with another recently introduced design, the DOME trap.

A new trap, the CSL I-SPy Insect Indicator((R)), has been assessed for monitoring adults of the principal crawling beetle pests of stored products in empty premises and on flat surfaces in grain stores and flour mills in the UK.The new trap was compared with the Igrox Insect Monitoring Peanut-free Bait Bag, the Storgard((R)) Flit-Trak M-2 trap and the Pantry Patrol((TM)) trap in laboratory arenas using six beetle species of important pest status or which might be difficult to trap. The Pantry Patrol trap performed least well. The I-SPy Insect Indicator containing a carob lure was as good as, or better than, the Flit-Trak M-2 trap containing both food oil and pheromone lures in catching Oryzaephilus mercator (81.0% and 51.1%, respectively), Typhaea stercorea (87.4% and 31.1%), Tribolium confusum (44.6% and 37.5%) and Cryptolestes ferrugineus (45.1 and 53.8%). For the Bait Bag the catches for these species were 67.2%, 59.5%, 55.7% and 81.9% respectively. The I-SPy Insect Indicator containing a carob lure and the Flit-Trak food oil was as good as the Flit-Trak M-2 trap in catching Sitophilus granarius (92.9% and 99.2%, respectively) and Rhyzopertha dominica (50.6% and 51.5%).In limited trials in premises with unknown levels of infestation, the I-SPy Insect Indicator containing the carob lure and the Flit-Trak food oil was at least as good as the Flit-Trak M-2 trap in a grain store. In a flour mill, the I-SPy Insect Indicator with this combination caught more species, higher numbers of insects and was better at demonstrating the presence of infestation. The I-SPy Insect Indicator is also sturdy, reusable, easy to assemble and leaves the catch easy to identify. Importantly, it contains no food which might act as a source of re-infestation. Crown Copyright (C) 2002 Published by Elsevier Science Ltd. All rights reserved.

The first UK trial to evaluate diatomaceous earth (DE) structural treatment was carried out during February 2002. A bin containing 20 t of "heating" insect-infested wheat resulted in migration of large numbers of O. surinamensis into the storage structure and surrounding area. The DE "Silico-Sec" was applied at approximately 10 g/m2 to the outsides, undersides and concrete floor beneath a nest of six, galvanized steel 3×3×4 m bins. Hand-operated, electric and gas-powered dusters were compared for ease of treatment. I-SPy Insect Indicators, incorporating multi-species lures, were placed before and after treatment. The number of insects trapped from an initial average of 406 per trap was reduced by 86-100%. Before treatment, a sample of the population was used to set up bioassays in petri dishes containing 100 insects each. Paired bioassays, one uncovered and one closed, were designated as treated and untreated controls. The mean mortality increased from 52% at 7 days to 99% after 14 days and 100% after 21 days. The mean temperature for this period was 6°C with the relative humidity at 80%. The low temperature and high humidity allowed testing under the most challenging environmental conditions for the DE dust. Photographed tracks gave an indication of insect movement after treatment. The electric-powered duster proved too powerful for the treatment of the steel structure, blowing away the dust that had been applied. The hand-operated model was very flexible and the speed of the treatment could be easily adjusted. The smaller, gas-powered applicator was well-suited for the treatment of small areas.

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.