Minimal Thermal Requirements for Development and Activity of Stored Product and Food Industry Pests (Acari, Coleoptera, Lepidoptera, Psocoptera, Diptera and Blattodea): A Review

All insects matter: a review of 160 entomology cases from 1993 to 2007 in Switzerland-Part II (Coleoptera, Hymenoptera, and Lepidoptera)

This article is the second part of the series analyzing the families recorded from 160 real cases in Switzerland between 1993 and 2007, focusing on species from orders Coleoptera, Hymenoptera, and Lepidoptera. A total of 46 distinct taxonomical units belonging to 15 families were identified. The most prominent was subfamily Silphinae with 9 recorded species, which was also the most dominant group in the dataset, occurring in 17.6% of all cases. It was closely followed by Dermestidae (12.6%), Histeridae (12.6%), and Staphylinidae (excluding Silphinae) (11.9%). The study highlights the importance and utility of a number of lesser-known species, at least in a forensic context, and gives insight into their ecology. We firmly believe that all insects matter. While not every species may become widely used, the more we learn about them, the greater the benefits for future criminal investigations.

Effects of Feeding Sources and Different Temperature Changes on the Gut Microbiome Structure of Chrysomya megacephala (Diptera: Calliphoridae)

Chrysomya megacephala (Diptera: Calliphoridae), commonly referred to as the oriental latrine fly, is a synanthropic blowfly species frequently associated with decomposing organic matter. This study sought to investigate the influence of various feeding substrates and temperature conditions, specifically constant temperatures of 15, 25, 35 °C, and variable temperatures averaging 23.31 °C, on the gut microbiome of C. megacephala. The microbiome analysis was conducted using the Illumina HiSeq platform for 16S rRNA gene sequencing in Changsha, China. Across all experimental conditions, the gut microbiome of C. megacephala yielded 1257 operational taxonomic units (OTUs), which were categorized into 26 phyla, 72 classes, 165 orders, 270 families, 516 genera, and 794 species. The study showed significant differences in the gut microbiome of C. megacephala between different feeding sources and temperature conditions across the lifespan. Low temperature had the potential to reduce the proportion abundance of bacterial communities in the gut microbiome, while high and variable temperature increased them. Metabolism was the main predicted function with diverse phenotypic characters in the gut microbiota of C. megacephala. The presence of diverse bacterial phenotypes in the gut microbiome of C. megacephala highlights its significant interest for medicine and offers promising applications in industry and agriculture.

Establishing the distribution of Carpophilus truncatus in Australia using an integrative approach for an emerging global pest

The nitidulid beetle Carpophilus truncatus is rapidly becoming a major pest of nut crops around the world. This insect first infested Australian almonds in 2013 and has since escalated to be the preeminent insect pest for the industry. Data pertaining to C. truncatus distribution are scant, but without awareness of its origin, distribution, and ecological factors that influence distribution, efforts to understand and manage the insect as a pest are stymied. Here, we employ an integrative approach to gain a multifaceted understanding of the distribution of C. truncatus in Australia. Methods employed were (1) reviewing historical records in insect collections to establish the presence of C. truncatus prior to commercial almond horticulture, (2) field trapping of insects to establish presence in regions of interest, (3) laboratory trials to determine the thermal limits of the organism, and (4) correlative species distribution modelling to describe its current distribution. We find that C. truncatus is more widespread across Australia than was previously known, with historical records preceding commercial almond production in Australia by a century. The methods developed in this study can be applied elsewhere in the world where C. truncatus is an emerging pest, or to novel pest species as they arise with increasing frequency in a globalised and warming world.

Impact of temperature on the bionomics and geographical range margins of the two-spotted field cricket Gryllus bimaculatus in the world: Implications for its mass farming

Gryllus bimaculatus (Orthoptera: Gryllidae) is widely considered an excellent nutrient source for food and feed. Despite its economic importance, there is limited information on the impact of temperature on the bionomics of this cricket to guide its effective and sustainable mass production in its geographical range. The biological parameters of G. bimaculatus were investigated at eight different temperatures ranging from 20-40˚C. The Insect Life-Cycle Modelling (ILCYM) program was used to fit linear and non-linear functions to the data to describe the influence of temperature on life history parameters and its farmability under the current and projected climate for 2050. Our results revealed that G. bimaculatus was able to complete its lifecycle in the temperature range of 20°C to 37°C with a maximum finite rate of population increase (= 1.14) at 35°C. The developmental time of G. bimaculatus decreased with increasing temperature. The least developmental time and mortality were attained at 32°C. The highest wet length and mass of G. bimaculatus occurred at 32°C. The lowest temperature threshold for G. bimaculatus egg and nymph development was approximated using linear regression functions to be at 15.9°C and 16.2°C with a temperature constant of 108.7 and 555.6 degree days. The maximum fecundity (2301.98 eggs per female), net reproductive rate (988.42 daughters/ generation), and intrinsic rate of natural increase (0.134 days) were recorded at 32°C and the shortest doubling of 5.2 days was observed at 35°C. Based on our findings G. bimaculatus can be farmed in countries with temperatures ranging between 20 and 37°C around the globe. These findings will help the cricket farmers understand and project the cricket population dynamics around the world as influenced by temperature, and as such, will contribute to more efficient farming.

Age determination of Chrysomya megacephala (Diptera: Calliphoridae) using lifespan patterns, gene expression, and pteridine concentration under constant and variable temperatures

Chrysomya megacephala (Fabricius, 1794) (Diptera: Calliphoridae), is a blowfly species widely studied in medical, veterinary, and entomological research. Our study examined the impact of constant (15, 20, 25, 30, and 35 °C) and variable (ranging from 21.0 to 25.4 °C, with an average of 23.31 °C) temperatures on the development and larval body length of C. megacephala. Additionally, we analyzed the age of the adult C. megacephala through pteridine content and related metabolic genes analysis. Our findings revealed three distinct growth patterns: isomorphen diagram, isomegalen diagram, and thermal accumulated models. At constant temperatures of 15, 20, 25, 30, and 35 °C, egg-hatching times were 44.5 ± 8.9, 26.7 ± 4.6, 12.6 ± 1.1, 11.0 ± 1.0, and 9.9 ± 1.9 h, respectively, while it was 15.3 ± 5.9 h at variable temperatures. The total development times from oviposition to adult eclosion in C. megacephala required 858.1 ± 69.2, 362.3 ± 5.9, 289.6 ± 17.8, 207.3 ± 9.3, and 184.7 ± 12.1 h at constant temperatures of 15, 20, 25, 30, and 35 °C, respectively. This duration was extended to 282.0 ± 64.1 h under variable temperatures. However, no significant differences were found in hatching times and the total developmental durations between 25 °C and variable temperatures. A developmental threshold temperature (D0) of 9.90 ± 0.77 °C and a thermal summation constant (K) of 4244.0 ± 347.0° hours were ascertained. Pteridine content patterns varied significantly across constant temperatures, but not between 25 °C and variable temperatures. Sex and temperature were identified as the primary factors influencing pteridine levels in the head of C. megacephala. Gene expression associated with pteridine metabolism decreased following adult eclosion, matching with increased pteridine concentration. Further investigations are needed to explore the use of pteridine cofactors for age-grading adult necrophagous flies. These findings provide valuable insights into the lifespan of C. megacephala, thereby offering valuable groundwork for forthcoming investigations and PMImin determination.

Urban Pest Abundance and Public Enquiries in Zurich 1991-2022

Zurich's Urban Pest Advisory Service (UPAS) aims to survey, control and reduce hazards posed by pests. Records submitted to the UPAS may not exactly correlate with abundance but can reveal patterns of change. These reflect changes in species, public and media perceptions and the effects of climate and COVID-19, along with the effectiveness of new pest controls. Records for Blattodea and Plodia interpunctella declined in the period 1990-2022, while Cimex lectularius and Psocoptera increased. Summer has typically revealed the largest number of insects reported and Google searches show parallel seasonal variations. The Blattodea declined five-fold over time, likely due to better pest control methods (gel baits). Aedes albopictus, though rare, was the subject of media reports and awareness campaigns, which resulted in much public interest. Vespidae are abundant and have been reported in sufficient numbers to warrant an analysis of seasonal records, suggesting that July temperatures affect numbers. COVID-19 restrictions led to more frequent reports of rodents, pigeons, Zygentoma and Stegobium paniceum. The long-term reporting to the UPAS gives a useful indication of the changing concerns about pests in Zurich.

Analysis of the Influence of Changing and Fixed Temperatures on the Growth and Pteridine Content in the Head of Adults Sarcophaga crassipalpis (Diptera: Sarcophagidae)

Flesh flies (Diptera: Sarcophagidae) are regarded as significant in medical and veterinary entomology, and their development models can be utilized as considerable markers to ascertain the minimum postmortem interval (PMImin). In this research, we explored the growth cycle and larval body length of Sarcophaga crassipalpis Macquart 1839 (Diptera: Sarcophagidae) reared under variable temperatures ranging from 15.7 to 31.1 °C, with an average of 24.55 °C and relative humidity ranges from 31.4 to 82.8% and at six fixed temperatures of 15, 20, 25, 30, 32, and then 35 °C. Moreover, pteridine from the head was used to assess adult age grading. Our results allowed us to provide three development models: the isomorphen chart, the isomegalen chart, and the thermal summation models. The time taken for S. crassipalpis to complete its development from larviposition to adult emergence at constant temperatures of 15, 20, 25, 30, 32, and 35 °C was 1256.3 ± 124.2, 698.6 ± 15.1, 481.8 ± 35.7, 366.0 ± 13.5, and 295.8 ± 20.5 h, respectively, except 35 °C, where all pupae were unable to attain adulthood. They lasted 485.8 ± 5.4 h under variable temperatures. The minimum developmental limit (D0) temperature and the thermal summation constant (K) of S. crassipalpis were 9.31 ± 0.55 °C and 7290.0 ± 388.4 degree hours, respectively. The increase in pteridine content exhibited variations across different temperatures. There was quite a considerable distinction in the pteridine contents of male and female S. crassipalpis at 15 °C (p = 0.0075) and 25 °C (p = 0.0213). At 32 °C and variable temperatures, the pteridine content between female and male S. crassipalpis was not statistically divergent. However, temperature and gender remain the main factors influencing the pteridine content in the head of S. crassipalpis. We aim to provide detailed developmental data on S. crassipalpis that can be used as a valuable resource for future research and PMI estimation.

Evaluation of Phosphine Resistance in Populations of Sitophilus oryzae, Oryzaephilus surinamensis and Rhyzopertha dominica in the Czech Republic

Phosphine is globally the most widely adopted fumigant for the control of storage pests. Recently, an increase in the frequency of stored-product pest resistance has been observed with significant geographical and interspecific variations. In this context, there are available data for the occurrence of resistant populations from America, Asia, Africa, and Australia, but there are few data in the case of Europe. Therefore, the aim of this work was to evaluate phosphine efficacy in important beetle pests of stored products, i.e., Sitophilus oryzae (L.), Oryzaephilus surinamensis (L.), and Rhyzopertha dominica (F.) sampled from the Czech Republic, using a rapid diagnostic test that is based on the speed to knockdown after exposure. Apart from the standard laboratory populations, which were used as the controls, we tested 56 field populations of these three species, collected in Czech farm grain stores. The survey revealed that 57.1% of the tested field populations were classified as phosphine-susceptible, based on the knockdown method used. However, profound variations among species and populations were recorded. The species with the highest percentage of resistant populations was R. dominica (71.4% of the populations; resistance coefficient 0.5-4.1), followed by S. oryzae (57.1% of the populations; resistance coefficient 0.8-6.9), and O. surinamensis (9.5% of the populations; resistance coefficient 0.5-2.9). Regarding the intra-population variability in response to phosphine (slope of the knockdown time regression), the laboratory and slightly resistant populations of all species were homogenous, whereas the most resistant populations were strongly heterogeneous. Our data show that the occurrence of resistance in the Czech Republic is relatively widespread and covers a wide range of species, necessitating the need for the adoption of an action plan for resistance mitigation.

Effects of Tissue Type and Temperature on Selected Life-History Traits of the Flesh Fly, Sarcophaga crassipalpis (Macquart, 1839) (Diptera: Sarcophagidae)

The flesh fly, Sarcophaga crassipalpis Macquart 1839 (Diptera: Sarcophagidae), colonizes estimation of the minimum post-mortem interval (min-PMI). This study examined the effects of different types of tissues and temperature on the development of S. crassipalpis. To the best of our knowledge, the present study is the first to investigate the effects of life-history information of S. crassipalpis. Larvae were reared on three tissue types, chicken heart, bovine minced meat, and bovine tongue, at five temperatures, 15, 20, 25, 30, and 32°C. Pupal and larval development time, adult weight, and pupal and larval survival differed significantly for tissue type and temperature. Temperature had a significant effect on pupal weight but tissue type did not significantly affect pupal weight. The duration of the larval and pupal stages (except of chicken heart, 30°C) decreased with increasing temperature, except for 32°C, in all tissue types. Larval survival was lowest at 32°C in bovine minced meat, bovine tongue, and chicken heart, and at 32°C, all pupae failed to reach the adult stage in minced meat. The results of this study highlight the necessity of considering larval diet and temperature in forensic investigations.

Gel Carriers for Plant Extracts and Synthetic Pesticides in Rodent and Arthropod Pest Control: An Overview

Insecticides and rodenticides form the basis of integrated pest management systems worldwide. As pest resistance continues to increase and entire groups of chemical active ingredients are restricted or banned, manufacturers are looking for new options for more effective formulations and safer application methods for the remaining pesticide ingredients. In addition to new technological adaptations of mainstream formulations in the form of sprays, fumigants, and dusts, the use of gel formulations is becoming increasingly explored and employed. This article summarizes information on the current and potential use of gel (including hydrogel) and paste formulations against harmful arthropods or rodents in specific branches of pest management in the agricultural, food, stored product, structural wood, urban, medical, and public health areas. Due to the worldwide high interest in natural substances, part of the review was devoted to the use of gels for the formulation of pesticide substances of botanical origin, such as essential or edible oils. Gels as emerging formulation of so called “smart insecticides” based on molecular iRNA disruptors are discussed.

Thermal Biology of Liorhyssus hyalinus (Hemiptera: Rhopalidae) and Nysius simulans (Hemiptera: Lygaeidae), Fed on the Milky Stage of Maize Grains

When quinoa, Chenopodium quinoa Willd., is cultivated in South America outside of its Andean origin, the heteropterans Liorhyssus hyalinus (Fabricius) and Nysius simulans Stål may emerge as important pests. Here we studied the development and reproduction of both species at different constant temperatures in the laboratory. Egg and nymphal development were investigated at 18, 22, 26, 30, 34, and 36°C. For both species, egg incubation time significantly decreased as the temperature increased. Nymphs did not successfully develop at 18°C and the total nymphal time significantly decreased as the temperature increased from 22 to 36°C. Based on a linear day-degree (DD) model, the lower developmental threshold (LDT) temperatures for eggs and nymphs were estimated to be 16.0 and 17.9°C for L. hyalinus, and 16.1 and 19.7°C for N. simulans, respectively. Thermal requirements for egg and nymphal development were 68.6 and 114.8 DD for L. hyalinus, and 77.7 and 190.3 DD for N. simulans, respectively. Reproduction and adult longevity were studied at 22, 26, 30, and 34°C. For both species preoviposition time decreased as temperature increased, and the oviposition period was longest at 26°C. The highest fecundity and egg viability were observed at 30°C, whereas longevities were higher at 22-26°C than at 30-34°C. As the lowest tested temperatures were not suitable to both heteropterans and 30°C was found to be the optimal temperature for development and reproduction, peak densities are expected in warm areas and seasons.

Modeling Temperature-Dependent Development Rate in Insects and Implications of Experimental Design

Characterizing the temperature-dependent development rate requires empirical data acquired by rearing individuals at different temperatures. Many mathematical models can be fitted to empirical data, making model comparison a mandatory step, yet model selection practices widely vary. We present guidelines for model selection using statistical criteria and the assessment of biological relevance of fits, exemplified throughout a Lepidoptera pest dataset. We also used in silico experiments to explore how experimental design and species attributes impact estimation accuracy of biological traits. Our results suggested that the uncertainty in model predictions was mostly determined by the rearing effort and the variance in development times of individuals. We found that a higher number of tested temperatures instead of a higher sample size per temperature may lead to more accurate estimations of model parameters. Our simulations suggested that an inappropriate model choice can lead to biased estimated values of biological traits (defined as attributes of temperature dependent development rate, i.e., optimal temperature for development and critical thresholds), highlighting the need for standardized model selection methods. Therefore, our results have direct implications for future studies on the temperature-dependent development rate of insects.

Sensitivity of polyphagous (Plodia interpunctella) and stenophagous (Ephestia kuehniella) storage moths to residual insecticides: effect of formulation and larval age

Pyralid moths, Ephestia kuehniella and Plodia interpunctella, are prevalent stored product pests. The insecticides are the main tool to control these moths in the stores. The data describing the response of these moths to insecticides are scarce. The lethal effect of the organophosphate, pyrethroid, and halogenated-pyrrole on moths larvae were compared in laboratory test. The hypothesis was that the very polyphagous P. interpunctella would have generally higher insecticide tolerance than that of the stenophagous E. kuehniella. Different insecticide concentrations were applied onto the inner surface of glass tube vials. Ten larvae of 14 or 21 d old of E. kuehniella and 7 or 14 d old of P. interpunctella were used by treatment. The larval mortality was checked after 24 h of exposure. The mortality was significantly influenced by age of larvae and the groups of chemicals. No differences among the efficacies of the tested formulations with identical active compounds were found, except significant different mortality of E. kuehniella on deltamethrin formulations. A comparison of analytical standards showed that P. interpunctella was less susceptible to the active ingredient pirimiphos-methyl than E. kuehniella, while E. kuehniella was less susceptible to deltamethrin than P. interpunctella. No differences between the two species were observed for chlorfenapyr. We therefore rejected the hypothesis that polyphagy/stenophagy can be a general predictor of insecticide tolerance in the two tested storage moths. The most important finding for effective use was that the young larvae of both species were more susceptible to tested insecticides than older larvae.

Synthetic and Natural Insecticides: Gas, Liquid, Gel and Solid Formulations for Stored-Product and Food-Industry Pest Control

The selective application of insecticides is one of the cornerstones of integrated pest management (IPM) and management strategies for pest resistance to insecticides. The present work provides a comprehensive overview of the traditional and new methods for the application of gas, liquid, gel, and solid physical insecticide formulations to control stored-product and food industry urban pests from the taxa Acarina, Blattodea, Coleoptera, Diptera, Hymenoptera, Lepidoptera, Psocoptera, and Zygentoma. Various definitions and concepts historically and currently used for various pesticide application formulations and methods are also described. This review demonstrates that new technological advances have sparked renewed research interest in the optimization of conventional methods such as insecticide aerosols, sprays, fumigants, and inert gases. Insect growth regulators/disruptors (IGRs/IGDs) are increasingly employed in baits, aerosols, residual treatments, and as spray-residual protectants for long-term stored-grain protection. Insecticide-impregnated hypoxic multilayer bags have been proven to be one of the most promising low-cost and safe methods for hermetic grain storage in developing countries. Insecticide-impregnated netting and food baits were originally developed for the control of urban/medical pests and have been recognized as an innovative technology for the protection of stored commodities. New biodegradable acaricide gel coatings and nets have been suggested for the protection of ham meat. Tablets and satchels represent a new approach for the application of botanicals. Many emerging technologies can be found in the form of impregnated protective packaging (insect growth regulators/disruptors (IGRs/IGDs), natural repellents), pheromone-based attracticides, electrostatic dust or sprays, nanoparticles, edible artificial sweeteners, hydrogels, inert baits with synthetic attractants, biodegradable encapsulations of active ingredients, and cyanogenic protective grain coatings. Smart pest control technologies based on RNA-based gene silencing compounds incorporated into food baits stand at the forefront of current strategic research. Inert gases and dust (diatomaceous earth) are positive examples of alternatives to synthetic pesticide products, for which methods of application and their integration with other methods have been proposed and implemented in practice. Although many promising laboratory studies have been conducted on the biological activity of natural botanical insecticides, published studies demonstrating their effective industrial field usage in grain stores and food production facilities are scarce. This review shows that the current problems associated with the application of some natural botanical insecticides (e.g., sorption, stability, field efficacy, and smell) to some extent echo problems that were frequently encountered and addressed almost 100 years ago during the transition from ancient to modern classical chemical pest control methods.

Frass produced by the primary pest Rhyzopertha dominica supports the population growth of the secondary stored product pests Oryzaephilus surinamensis, Tribolium castaneum, and T. confusum

Primary pests such as Rhyzoperta dominica may increase the contents of dockage, dust, and frass in grain mass. Although it has been suggested that frass can affect the population growth of stored product pests and ecological interactions among primary and secondary pests in stored grain, this has not been validated experimentally. Therefore, this work experimentally tested the hypothesis that R. dominica wheat frass may support population increases in secondary pests such as Tribolium confusum, T. castaneum, and Oryzaephilus surinamensis for the first time. The effect of frass on secondary pest performance was compared with the effects of various physical qualities of wheat grain (i.e., intact grain kernels, grain fragments, flour, grain + frass) and an artificially enriched control diet (milled wheat kernels, oat flakes, and yeast). The results showed that the clean intact grain kernels did not support the population growth of any tested species, and the nutrient-rich control diet provided the best support. Frass was a significantly better food medium for O. surinamensis and T. castaneum than flour or cracked grain, while T. confusum performed equally well on flour and frass. Our results showed that in terms of food quality and suitability for the tested species, frass occupied an intermediate position between the optimized breeding diet and simple uniform cereal diets such as cracked grain or flour. The results suggest that (i) the wheat frass of primary pest R. dominica is a riskier food source for the development of the tested secondary pests than intact or cracked wheat grain or flour; (ii) frass has the potential to positively influence interspecific interactions between R. dominica and the tested secondary pests; and (iii) wheat grain should be cleaned if increases in R. dominica populations and/or accumulated frass are detected.

Automated Applications of Acoustics for Stored Product Insect Detection, Monitoring, and Management

Simple Summary

A variety of different acoustic devices has been commercialized for detection of hidden insect infestations in stored products, trees, and soil, including a recently introduced device demonstrated in this report to successfully detect rice weevil immatures and adults in grain. Several of the systems have incorporated digital signal processing and statistical analyses such as neural networks and machine learning to distinguish targeted pests from each other and from background noise, enabling automated monitoring of the abundance and distribution of pest insects in stored products, and potentially reducing the need for chemical control. Current and previously available devices are reviewed in the context of the extensive research in stored product insect acoustic detection since 2011. It is expected that further development of acoustic technology for detection and management of stored product insect pests will continue, facilitating automation and decreasing detection and management costs.

Abstract

Acoustic technology provides information difficult to obtain about stored insect behavior, physiology, abundance, and distribution. For example, acoustic detection of immature insects feeding hidden within grain is helpful for accurate monitoring because they can be more abundant than adults and be present in samples without adults. Modern engineering and acoustics have been incorporated into decision support systems for stored product insect management, but with somewhat limited use due to device costs and the skills needed to interpret the data collected. However, inexpensive modern tools may facilitate further incorporation of acoustic technology into the mainstream of pest management and precision agriculture. One such system was tested herein to describe Sitophilus oryzae (Coleoptera: Curculionidae) adult and larval movement and feeding in stored grain. Development of improved methods to identify sounds of targeted pest insects, distinguishing them from each other and from background noise, is an active area of current research. The most powerful of the new methods may be machine learning. The methods have different strengths and weaknesses depending on the types of background noise and the signal characteristic of target insect sounds. It is likely that they will facilitate automation of detection and decrease costs of managing stored product insects in the future.

Storage of Cereals in Warehouses with or without Pesticides

Simple Summary

For decades, the use of various synthetic pesticides has been the key factor in the proper and long-term storage of cereals. Unfortunately, we are faced with non-acceptable data regarding the effects of synthetic pesticides. Due to this, further steps have been made in order to take measures to reduce the use and risk of chemical pesticides by 50% by 2030 and to reduce the use of more dangerous pesticides by 50% by 2030. The concept of integrated pest management has been promoted as a dynamic and flexible approach leading to the reduction of chemical pesticide usage and their negative effects on the environment. The aim of this review is to indicate how cereals stored in silos or warehouses are handled and what measures are taken to preserve them, to describe the situation regarding pesticides, and to point out the problems occurring during application and the possibility of applying substitutions. It has to be taken into account that many of these measures cannot completely control insect or mite populations and are very demanding because of the need for more knowledge and experience, better equipment, greater financial investment, and a higher awareness of the impacts of pesticides not only for agricultural producers and storage keepers, but also for consumers.

Abstract

At a time when there is much talk of reducing pesticide use and the implementation of integrated pest management, mainly in fields and glass-houses, it is appropriate to consider how cereals in storage are handled and what measures are taken to protect them against insects and other pests. For decades, the use of various synthetic pesticides has been the basis for the proper and long-term storage of cereals, primarily free of insects and mites, but also fungi and their mycotoxins and rodents. However, due to the registered negative effects of synthetic pesticides, such as dichloro-diphenyl-trihloroethane (DDT) or methyl bromide, on human health and the environment, and the appearance of resistance to, e.g., malathion, researchers have been looking for new acceptable control measures. Due to the proven and published non-acceptable data regarding synthetic pesticide effects, a combination of physical, mechanical, and biological measures with the minimal use of synthetic pesticides, under the name of integrated pest management, have been promoted. These combinations include high and low temperatures; the removal of dockages; and the application of pheromones, diatomaceous earth, and natural compounds from various plants, as well as inert gases, predators, and parasites. A ban of any synthetic pesticide usage is currently being considered, which emphasizes the fact that protection should only be performed by measures that do not leave harmful residues. However, the facts show that the application of physical, mechanical, and/or biological measures, besides the fact that they are not necessarily efficient, is very demanding because more knowledge and experience is required, as well as better equipment, greater financial investment, and awareness raising not only for agricultural producers and storage keepers, but also for consumers. In order to use these measures, which are less hazardous to humans and the environment, it is necessary to adapt regulations not only to speed up the registration protocols of low-risk pesticides, but also to prescribe criteria for placing agricultural products on the market, as well as quality standards, i.e., the permitted number of present insects, in addition to their parts in certain types of food. Additionally, we should be aware of control measures for protecting novel food and other non-traditional foods. It is important to continue to combine different protection measures, namely integrated pest management, until all of the other new procedures that must be carried out during the period of storing cereals and other products are clear, in order to ensure the best quality of final products for consumers.

Thermal ecosystem engineering by songbirds promotes a symbiotic relationship with ants

Nesting birds can act as thermal ecosystem engineers by providing warm habitats that may attract arthropods to colonise the nest structure. This cohabitation of birds and nest-dwelling invertebrates may foster symbiotic relationships between them, but evidence is lacking. We investigated whether ants are attracted to bird nests by the heat generated by the hosts, and/or the nests' structural insulation properties, to raise their broods (larvae and/or pupae) in advantageous thermal conditions. We found that the endothermic activity of birds within their nests created 'heat islands', with thermal conditions potentially promoting the survival and development of ant larvae in cool environments. We experimentally confirmed that the presence of heat within bird nests, and not the structure itself, attracted the ants to colonise the nests. As ants might benefit from exploiting warm bird nests, this may be a previously overlooked commensal, mutualistic or parasitic relationship which may be ecologically significant and globally widespread among various nesting birds and reproducing ants. Similar interspecific interactions may exist with other arthropods that reproduce in avian and mammalian nests. Further research is needed to reveal the nature of these relationships between such taxa, and to understand the role of warm-blooded animals as thermal ecosystem engineers.

Inexpensive Screening Method to Validate the Efficacy of Ethanedinitrile Fumigant on the Forest Invasive Nematode Pest Bursaphelenchus xylophilus

At a global scale, the sustainability of forests is endangered by multiple invasive species, including the pine wood nematode (Bursaphelenchus xylophilus), a quarantine pest. International laws and standards require that all exported wood coming from countries in which B. xylophilus is present be chemically or physically treated. Since a major fumigant, methyl bromide, was banned, there has been a need to generate data for alternative fumigants, such as ethanedinitrile (EDN), for this purpose. Since the field screening of fumigants (i.e., the application of various doses to and exposure times of naturally infested wood logs) is prohibitively expensive, the aim of this study was to develop a quick and inexpensive laboratory method. Here, we suggest and describe an innovative method based on sawdust cultures for EDN efficacy screening. In the validation part of this study, we demonstrated (i) the high survival of the nematodes in the sawdust and (ii) the high efficacy of EDN against this pest under in vitro conditions; 100% mortality was observed after 6 h of EDN exposure to a dose of 25 g/m3. In particular, our newly developed model system could be used for the initial screening of various doses of and exposure protocols for EDN and similar types of fumigants developed with the intention of regulating B. xylophilus occurrence in exported wood. It is believed that the validated method may help to develop new and effective EDN fumigation procedures and thereby contribute to the long-term protection of forests worldwide.