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Background: Orius laevigatus, a minute pirate bug, is a highly effective beneficial predator of crop pests including aphids, spider mites and thrips in integrated pest management (IPM) programmes. No genomic information is currently available for O. laevigatus, as is the case for the majority of beneficial predators which feed on crop pests. In contrast, genomic information for crop pests is far more readily available. The lack of publicly available genomes for beneficial predators to date has limited our ability to perform comparative analyses of genes encoding potential insecticide resistance mechanisms between crop pests and their predators. These mechanisms include several gene/protein families including cytochrome P450s (P450s), ATP binding cassette transporters (ABCs), glutathione S-transferases (GSTs), UDP-glucosyltransferases (UGTs) and carboxyl/cholinesterases (CCEs). Methods and findings: In this study, a high-quality scaffold level de novo genome assembly for O. laevigatus has been generated using a hybrid approach with PacBio long-read and Illumina short-read data. The final assembly achieved a scaffold N50 of 125,649 bp and a total genome size of 150.98 Mb. The genome assembly achieved a level of completeness of 93.6% using a set of 1658 core insect genes present as full-length genes. Genome annotation identified 15,102 protein-coding genes - 87% of which were assigned a putative function. Comparative analyses revealed gene expansions of sigma class GSTs and CYP3 P450s. Conversely the UGT gene family showed limited expansion. Differences were seen in the distributions of resistance-associated gene families at the subfamily level between O. laevigatus and some of its targeted crop pests. A target site mutation in ryanodine receptors (I4790M, PxRyR) which has strong links to diamide resistance in crop pests and had previously only been identified in lepidopteran species was found to also be present in hemipteran species, including O. laevigatus. Conclusion and significance: This assembly is the first published genome for the Anthocoridae family and will serve as a useful resource for further research into target-site selectivity issues and potential resistance mechanisms in beneficial predators. Furthermore, the expansion of gene families often linked to insecticide resistance may be an indicator of the capacity of this predator to detoxify selective insecticides. These findings could be exploited by targeted pesticide screens and functional studies to increase effectiveness of IPM strategies, which aim to increase crop yields by sustainably, environmentally-friendly and effectively control pests without impacting beneficial predator populations.

Several biological control agents of the hemipteran insect families Miridae, Anthocoridae and Pentatomidae, as well as mites of the family Phytoseiidae are known as zoophytophagous predators, a subset of omnivores, which are primarily predaceous but also feed on plants. It has been recently demonstrated that zoophytophagous predators are capable of inducing defenses in plants through their phytophagy. Despite the vast fundamental knowledge on plant defense mechanisms in response to herbivores, our understanding of defense induction by zoophytophagous predators and applied implications is relatively poor. In this review, we present the physiological basis of the defense mechanisms that these predators activate in plants. Current knowledge on zoophytophagous predator-induced plant defenses is summarized by groups and species for the predators of economic importance. Within each group, feeding habits and the efects of their induced-plant defenses on pests and natural enemies are detailed. Also, the ecological implications of how the induction of defenses mediated by zoophytophagous predators can interact with other plant interactors such as benefcial soil microorganisms and plant viruses are addressed. Based on the above, we propose three approaches to exploit zoophytophagous predator-induced defenses in crop protection and to guide future research. These include using predators as vaccination agents, employing biotechnological approaches, as well as applying elicitors to elicit/mimic predator-induced defenses.

Thrips of the subtropical genus Scirtothrips are emerging as important pests in several crops. Scirtothrips dorsalis has been increasingly invading new areas outside of its native region of South and East Asia causing economic damage to several crops. Scirtothrips inermis is another polyphagous species with worldwide distribution. Both species are polyphagous, and in recent years have emerged as key pests in strawberry. In this study, we first evaluated the predation and oviposition rate of commercially available phytoseiid predatory mites Amblyseius swirskii, Amblydromalus limonicus, Transeius montdorensis, and Neoseiulus cucumeris on larval stages of both Scirtothrips species, and oviposition rates of predatory mites on the supplementary food source Artemia franciscana cysts were also assessed. Predatory mites equally accepted both thrips species as prey and showed stable oviposition rates on these diets. Amblyseius swirskii and A. limonicus were the most voracious, also exhibiting the highest oviposition rate of the predators tested. We further evaluated the biological control potential of predatory mites and anthocorid predators Orius laevigatus and Orius limbatus in a greenhouse experiment. Predators were released preventively and supported with Artemia cysts before the introduction of S. inermis . Both Orius predators achieved good control of the pest, with O. limbatus developing higher numbers than O. laevigatus . Regarding phytoseiids, A. swirskii and A. limonicus both controlled the pest and built higher populations than T. montdorensis and N. cucumeris . Our results show that a preventive strategy based on phytoseiid or anthocorid predators in strawberry can be effective in suppressing S. inermis .

The addition of non-crop floral resources is known to improve the fitness of many beneficial arthropods. Orius insidiosus (Say; Heteroptera: Anthocoridae) is a predator of several economically important pests and is known to feed on pollen. Spanish needles, Bidens alba L., and Leavenworth’s tickseed, Coreopsis leavenworthii Torrey & Gray (both Asteraceae), are two Florida native wildflowers that may serve as sources of pollen beneficial to O. insidiosus. The current study investigated the effects of adding flowers from C. leavenworthii and B. alba to the diet of captive O. insidiosus on longevity, nymphal development time, and cannibalism. A mixed diet of flowers and thrips prey increased O. insidiosus adult female longevity. Nymphal development time was reduced when B. alba was added to thrips when compared to a diet of thrips alone. Interestingly, cannibalism was low in all instances, suggesting a negligible effect of cannibalism on O. insidiosus except perhaps in extreme situations. These results indicate that B. alba and C. leavenworthii flowers can increase longevity and fitness of O. insidiosus, thus providing support for the use of these plants to enhance natural enemy services. Se sabe que la adición de recursos florales no agrícolas mejora la aptitud de muchos artrópodos beneficiosos. Orius insidiosus (Say; Heteroptera: Anthocoridae) es un depredador de varias plagas económicamente importantes y se sabe que se alimenta de polen. El mazote blanco, Bidens alba L., y la semilla de garrapata de Leavenworth, Coreopsis leavenworthii Torrey & Gray (ambas Asteraceae), son dos flores silvestres nativas de la Florida que pueden servir como fuentes de polen beneficioso para O. insidiosus. El estudio actual investigó los efectos de agregar flores de C. leavenworthii y B alba a la dieta de O. insidiosus en cautiverio sobre su longevidad, tiempo de desarrollo ninfal y canibalismo. Una dieta mixta de flores y trips aumentó la longevidad de las hembras adultas de O. insidiosus. El tiempo de desarrollo ninfal se redujo cuando se añadió B. alba a los trips en comparación con una dieta de trips solos. Curiosamente, el canibalismo fue bajo en todos los casos, lo que sugiere un efecto insignificantedecanibalismo en O. insidiosus, excepto quizás en situaciones extremas. Estos resultados indican que las flores de B. alba y C leavenworthii pueden aumentar la longevidad y la aptitud de O. insidiosus, brindando así apoyo para el uso de estas plantas en la mejora de los servicios contra los enemigos naturales.

The lepidopteran pest, Spodoptera frugiperda (JE Smith), spread rapidly after its first detection in China and has caused significant yield loss to maize production in the southwestern part of the country. Although natural enemies of S. frugiperda are present in the field, biological control using naturally distributed predators is ineffective because their underlying populations are too low. To enhance our understanding of the potential role of natural enemies in regulating this invasive pest, functional response experiments were conducted to quantify the response of two predators, Orius sauteri (Poppius) (Hemiptera: Anthocoridae) and Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), in terms of consumption of S. frugiperda. Experimental results revealed that the predatory effects of nymphs of O. sauteri and H. axyridis on the eggs and larvae of S. frugiperda fitted Holling’s Type II functional response model. Importantly, the theoretical maximum number of prey consumed per day (Na-max), the instantaneous attack rate (a′) and the handling time (Th) of O. sauteri nymphs on S. frugiperda eggs were 15.19, 0.7444 and 0.049 d, respectively; and the parameters on first instar larvae of S. frugiperda were 700.24, 0.5602 and 0.0008 d, respectively. These data contrast to those of H. axyridis, where the Na-max, a′ and Th of adults on eggs of S. frugiperda were 130.73, 1.1112 and 0.085 d, respectively, and on the first instar larvae of S. frugiperda were 1401.1, 0.8407 and 0.0006 d, respectively. These results revealed that H. axyridis is a highly voracious predator of the eggs and young larvae of S. frugiperda and O. sauteri could also be used as biocontrol agent of this pest. Our work provides a theoretical framework for the application of natural enemies to control S. frugiperda in the field. Further research is required to strategize conservation biological control approaches in the field to increase populations of these predators and enhance the suppression of S. frugiperda.

Omnivores obtain resources from more than one trophic level, choosing food based on quantity and quality. They usually engage in intraguild predation (IGP) when prey is scarce. Orius laevigatus is an example of omnivore that becomes superior predator of the predatory mite Amblyseius swirskii when released in a combined system under low levels of the preferred prey, the thrips Frankliniella occidentalis . Here, we test two genetically enhanced O. laevigatus strains for bigger size and better fitness feeding on pollen (BIG30 and 2POL-11, respectively), hence with a wider dietary diversification, to elucidate the potential effects on prey preference and IGP on the predatory mite, in comparison with a commercial population of O. laevigatus . To do that, predation rates were registered on adult phytoseiids solely or in a choice situation at different availability ratios of adult thrips under laboratory conditions. The effect of pollen as supplemental food on IGP and prey preference was examined, too. We found that our two enhanced lines killed up to 9% less predatory mites and fed preferably on adult thrips, compared to the commercial population. While BIG30 showed a significantly higher total predation rate, killing up to 150% more adult thrips, 2POL-11 is defined as an efficient user of resources, switching between different prey and pollen showing low IGP. Pollen supplementation had a significant effect on reducing IGP, but only for 2POL-11 the influence on prey preference was significant. The theory of intraguild predation and the impact of prey switching on food webs and biological control strategies are also discussed.

There is a need for comprehensive research on the species structure and the population dynamics of the most common aphidophagous species. A critical factor of the effectiveness of aphid biocontrol is the ratio of beneficial polyphagous (generalist) to oligo- or monophagous (specialist) species within the various trophic groups. Aphids' population density and environmental conditions influence the development and potential feeding of useful insects. The present study aimed to determine the community structure, relationships and diversity between aphids and their aphidophagous species in alfalfa fields using the following methods: sweeping with an entomological net, the quadratic method, coloured sticky board method, route survey method and visual observations. Research on the structure of the aphid–aphidophagous community revealed that aphidophagous species belong to three groups: (1) polyphagous predatory bugs from the families Anthocoridae and Nabidae, (2) oligophagous and polyphagous predators from the families Coccinellidae, Syrphidae and Chrysopidae; and (3) monophagous and oligophagous parasitoids, primarily from the families Aphidiidae and Ichneumonidae. From mid-May to June, there was a sufficiently large potential for aphidophagous species (Coccinellidae, Syrphidae, Chrysopidae, Anthocoridae and Nabidae) to control aphids, while in September, predatory ladybirds from the Coccinellidae family were the main biological control agents. Coccinellidae (Coleoptera) exhibited the highest values of diversity, dominance and richness indices among insect groups in the aphid–aphidophagous community. The existence of diverse aphidophagous species in alfalfa fields suggests that these predators can complement each other, leading to effective biological control of aphids. The synergy among different predator species holds promise for enhancing the overall efficacy of integrated pest management strategies.

Augmentative biological control has experienced a remarkable success, particularly in protected crops. Yet integrated pest management (IPM) still requires corrective treatments to manage some pests, which may result in detrimental effects on biological control agents (BCAs). Hence, the choice of selective pesticides is crucial for an effective pest management. A complementary approach is the genetic improvement of BCAs resistant to some key pesticides, allowing their joint use in IPM. The predator Orius laevigatus (Fieber) (Hemiptera: Anthocoridae) is widely introduced in protected crops to supress thrips and other small pests. Spinosad is a naturally derived biopesticide and a key compound in both conventional and organic crops. However, spinosad has been reported as slightly to moderately harmful to O. laevigatus . Here we explored and exploited the intra-specific variation in spinosad susceptibility in wild and commercial populations of O. laevigatus to select a spinosad-resistant strain. We found a 48.8-fold variation in susceptibility to spinosad among 35 populations, obtaining a lethal concentration (LC 50 ) of 166.3 mg l −1 for the baseline. A spinosad-resistant strain (SPI38) was successfully obtained (LC 50  = 2110.0 mg l −1 ). The resistance was stable for ten generations without selection pressure and was expressed in all life stages, particularly from the 3 rd nymphal instar to adult. SPI38 showed cross-resistance to spinetoram and inhibitors of the detoxification enzymes were not able to restore susceptibility, which suggest a target-site resistance mechanism. The resistance achieved may be sufficient to allow survival of adults and nymphs of O. laevigatus exposed to field applications of spinosad across the cropping season.

The predatory bug, Orius laevigatus (Fieber, 1860) (Hemiptera: Anthocoridae), is an important biological control agent and widely used for augmentative biological control of the western flower thrips, Frankliniella occidentalis Pergande, 1895 (Thysanoptera: Thripidae) in greenhouse crops. This bug is generally reared using the Mediterranean flour moth, Ephestia kuehniella Zeller, 1879 (Lepidoptera: Pyralidae). The aim of this study was to determine the effects of E. kuehniella eggs produced by adult moths reared on different larval diets on the performance of O. laevigatus. The diets were 95% cornmeal + 5% yeast (CY diet), 53.3% cornmeal + 26.7% wheat bran + 15% Glycerine + 5% yeast (CBGY diet) and 53.3% wheat flour + 26.7% wheat bran + 15% Glycerine + 5% yeast (WBGY diet). Laboratory studies started with newly emerged nymphs of O. laevigatus kept in a climate chamber at 27°C, 60% relative humidity and a 14L :10D photoperiod. Eggs of E. kuheniella adults that were fed on one of the three different larval diets were provided to the nymphs as a source of food and bean pods of water. Following adult emergence, all individuals were sexed, and female and male pairs were put in plastic containers (30 cc) with eggs of E. kuehniella and bean pods. Nymphal development time, fecundity and longevity of O. laevigatus were not differently affected by feeding on the eggs of E. kuehniella reared on the three diets. In addition, the daily and total egg consumption of adults of O. laevigatus were similar. Because the CY diet eggs contain more nutrients, their consumption by nymphs was lower. This study indicates that the CY diet is an adequate diet for rearing E. kuehniella for producing eggs for rearing O. laevigatus.

The paper presents new data on the distribution of 12 rare and little-known true bug species in the Asian part of Russia. Sciocoris macrocephalus Fieber, 1851 (Pentatomidae) was discovered for the first time in Western Siberia. Salda micans Jakovlev, 1889 (Saldidae) and Orius niger (Wolff, 1811) (Anthocoridae), collected in the north of Amur Province, are new to the fauna of the Russian Far East. Orius niger and Bathysolen nubilus (Fallén, 1807) (Coreidae) are recorded for the first time for Irkutsk Province. Seven species have been added to the list of the Yakutia fauna: O. niger and Lyctocoris campestris (Fabricius, 1794) (Anthocoridae), Eurycolpus flaveolus (Stål, 1858) (Miridae), Aradus pulchellus pulchellus J. Sahlberg, 1878 (Aradidae), Geocoris itonis Horváth, 1905, Drymus sylvaticus (Fabricius, 1775), and Peritrechus geniculatus (Hahn, 1832) (Lygaeidae).