This study investigates the gut microbiota of newly emerged adult females and males of five economically important Anastrepha species (Tephritidae) – A. ludens, A. obliqua, A. serpentina, A. striata, and A. fraterculus – by analyzing 16S rRNA amplicon sequences from 36 samples collected from ecologically relevant fruit hosts and locations in Mexico. We chose to concentrate only on newly emerged adults to identify bacteria that females could potentially transmit vertically to progeny via oviposition, a topic that remains poorly studied. Results revealed that Proteobacteria dominated the microbiota in all species, but substantial variation was observed in genus-level composition. Differentially abundant genera included Enterobacter, Gluconobacter, Tatumella, Providencia, Ochrobactrum, Siccibacter, Sphingobacterium, and Sphingobium. Significant differences in alpha diversity were observed between species, particularly between A. obliqua and A. striata, and between A. obliqua and A. serpentina based on the Shannon index. Anastrepha ludens, A. obliqua, and A. striata males exhibited higher species richness than females, although these differences were not statistically significant within individual species likely due to limited sample size. Interestingly, across all species, significant differences in microbiota composition were observed between males and females. Our findings suggest that morphological, physiological (i.e., metamorphosis) and ecological factors, such as possible gut structural differences and host fruit preferences, may influence the composition of the gut microbiota, potentially affecting the ecological adaptability and pest behavior of these flies.

This study presents the first record of Miyalachnus sorini Kanturski & Lee, 2024 (Aphididae: Lachninae) in South Korea, thereby extending its known distribution beyond Japan and identifying a new host plant, Prunus sargentii (Rosaceae). We describe diagnostic morphological traits across multiple life stages and compare them with those of Japanese populations. Comparative analyses with Japanese populations demonstrated consistent morphological differentiation, notably elevated ratios of the ultimate rostral segment to antennal segments across multiple morphs in the Korean population, indicating potential ecological adaptation. DNA barcoding using the mitochondrial cytochrome c oxidase I gene revealed low intraspecific divergence (average 0.2%) and interspecific divergence (average 10.5%) between Miyalachnus sp. and M. sorini. Haplotype analysis was performed to investigate the relationship between host plants and cryptic genetic diversity. These findings enhance our understanding of the morphological and genetic diversity of M. sorini and underscore the importance of monitoring its spread for informed pest management strategies.

True bugs (Hemiptera: Acanthosomatidae, Coreidae, and Pentatomidae) include harmful crop pests affecting global agriculture, with different species displaying distinct optimal conditions for development and using different habitats. Over a 2-year period, this research investigates how habitat variation and altitude can influence the species composition of true bugs and their egg parasitoids in South Tyrol (North Italy), unveiling different trends in their population and diversity across habitats: apple orchards, urban areas, and forests. A total of 25 true bug species were sampled. Urban environments hosted the highest bug abundance, predominantly driven by the invasive Halyomorpha halys, while forests showed a higher prevalence of native species such as Pentatoma rufipes and Palomena prasina. Altitude significantly influenced species composition, with H. halys and P. rufipes abundance negatively and positively correlated with altitude, respectively. A total of 12 parasitoid species (Hymenoptera: Eupelmidae, and Scelionidae) emerged from the field-collected bug eggs, including the exotic Trissolcus japonicus, predominantly associated with H. halys in urban areas. Native parasitoids exhibited higher parasitism rates on native bug species, indicating co-evolutionary relationships. The results give an insight into the ecological dynamics of local true bug species and their egg parasitoids, and highlight the value of natural and urban areas for conserving both hemipteran and parasitoid species richness and abundance.

Anaesthesia methods play a crucial role in ensuring the integrity of the animal during experimental studies. This study investigates the impact of two anaesthesia methods, CO₂ and cold treatment, on an insect antennal response to synthetic alarm pheromone compounds. Adult worker hornets were anesthetised, and their antennae excised and tested using an electroantennography set-up with controlled stimulation of alarm pheromone components. Results showed that CO₂-anesthetised hornets exhibited robust antennal responses, while cold-anesthetised individuals displayed none. This result suggests that freezing may impair the functionality of olfactory receptors. In contrast, CO₂ anaesthesia preserves receptor integrity, offering reliable and interpretable results. This study highlights the importance of selecting appropriate anaesthesia techniques to avoid artefacts in insect sensory physiology research and underscores the ecological relevance of studying Vespa velutina nigrithorax alarm signalling.

Spermophagus niger L. is a well-known pest of roselle (Hibiscus sabdariffa L.) seeds in West Africa and responsible of mostly damage. This study first reported the presence of S. niger Motschulsky in kenaf (Hibiscus cannabinus L.) seeds stored. Samples of kenaf seeds collected at four locations in Burkina Faso. In the laboratory, the seeds were incubated until adults’ insects emerged. The emerged insects were first identified morphologically and their biodemographic parameters studied under controlled conditions (32°C ± 0.1, 43% ± 1 r.h.). The results showed that S. niger (Coleoptera: Chrysomelidae) was the only pest encountered on H. cannabinus seeds in storage and was able to complete its development cycle there. Over the course of its life, which lasts an average of 7 days, the female laid around 40 eggs, resulting in 24 individuals dominated by females. The embryonic and total development time were average 5 and 26 days, respectively. Spermophagus niger population doubled in 6 days, with an intrinsic rate of natural increase of 0.105. The finite rate of increase and the generation time averaged 1.11 and 31.86 days, respectively. This study pointed out for the first time that S. niger is able to evolve successfully on H. cannabinus seeds in storage conditions and therefore, could be a serious pest of this important crop. The data from this study could therefore be used as a basis for the post-harvest management of H. cannabinus seeds.

The alfalfa weevil Hypera postica Gyllenhal (Coleoptera: Curculionidae) is one of the most destructive alfalfa pests in the world, resulting in substantial economic losses. However, the amount of damage can be reduced by larval parasitoids of the genus Bathyplectes Förster (Hymenoptera: Ichneumonidae) as a conservation biological control strategy. Parasitoids are currently identified by morphological body characteristics, cocoon morphology, and/or DNA analysis, but geometric morphometrics (GM) applied to the wing vein arrangement may also reveal differences between specimens. We distinguished 61 B. anurus (Thomson) and 41 B. curculionis (Thomson) specimens, based on the appearance of the cocoon. GM revealed statistically significant differences in wing vein patterns and fore wing shapes between species, but not between sexes within the same species. The 1 M + 1R1 cell, also known as the horsehead cell, was revealed to be an easy and reliable morphological character for species differentiation. Despite the New World literature, this is the first European report providing a visual method to differentiate B. anurus from B. curculionis. This study highlights the importance of precise species identification methods, such as geometric morphometry. It can contribute to a better implementation of biological control strategies against the alfalfa weevil in Spain and other Mediterranean countries.

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is an invasive tropical pest that is currently expanding in its geographical range into temperate regions. This study examined the temporal and spatial dynamics of B. dorsalis along an altitudinal gradient in Mpumalanga Province, South Africa, in its southernmost adventive limit, which experiences a temperate climate with dry winters. Populations were monitored from October 2020 to October 2022 at three sites with altitudes ranging from 452 to 1 741 m above sea level. At each site, clusters of attractant-based traps (methyl eugenol and three-component Biolure) were set up and serviced at least monthly. We analysed the effects of climate, time of the year, altitude, and landscape on B. dorsalis abundance. Single population peaks of B. dorsalis were recorded from mid-summer to autumn in all sites, with higher prevalence at the low-altitude site. In the low- and mid-altitude sites, catches were recorded year-round, while at the high-altitude site, there were no catches for four to six months after onset of winter. Higher B. dorsalis catches were recorded as temperatures increased and precipitation decreased. Catches were higher in commercial orchards and home gardens compared to abandoned orchards. These findings provide valuable information for improving simulation models of B. dorsalis distribution and population growth that can be used to inform the management of this pest.

Water hyacinth is an invasive aquatic plant that has been associated with major negative economic and ecological impacts in water systems worldwide, including Rwanda, since its establishment in the country in the 1960s. While biological control is considered the most sustainable management method, the success of biocontrol agents depends on various abiotic factors, with temperature being critical. This study assessed the suitability of potential water hyacinth biocontrol agents such as: Neochetina weevils, Megamelus scutellaris Berg (Hemiptera: Delphacidae), and Cornops aquaticum Bruner (Orthoptera: Acrididae) for regions with a temperate climate by testing their thermal boundaries. Using thermal physiology limits and CLIMEX modelling, we found that Neochetina eichhorniae Warner and N. bruchi Hustache (Coleoptera: Curculionidae) had lower thermal minimums (CTmin) of 2.4°C and 2.6°C, respectively, compared to Megamelus scutellaris (4.7°C) and Cornops aquaticum (6.2°C). CLIMEX modelling predicted the suitability of Neochetina weevils and C. aquaticum across Rwanda, while M. scutellaris appeared unsuitable for the colder northern regions of the country but appropriate for the central and eastern regions. These findings suggests that the historical failure of Neochetina weevils introduced to Rwandan water bodies in 2000 was not due to temperature extremes. Rather, other factors such as release numbers or water quality may have played a role. This study provides crucial information for future biocontrol efforts in Rwanda and similar temperate regions, highlighting the importance of pre-release thermal tolerance assessments and climate modelling to predict biocontrol agent establishment and efficacy.

Pineapple cultivation is of economic importance for farmers; however, pineapple production can be affected by pests and diseases. Recently, the presence of mealybugs and pineapple mealybug wilt-associated viruses (PMWaV)-1, -2, and -3 has been reported in the provinces of Satipo and Chanchamayo, in Peru’s central jungle. This study aimed to molecularly identify mealybugs collected from the Hawaiiana cultivar and the MD-2 hybrid in those provinces to determine if they are indeed hosts of the PMWaV-1, -2, and -3. Through amplification and sequencing of the internal transcribed spacer ribosomal genes, the mealybugs were identified as Dysmicoccus brevipes. In the phylogenetic analysis of these D. brevipes, Peruvian isolates were associated with isolates from India, China, Taiwan, and Japan. In addition, our results confirmed the presence of PMWaV-1, -2, and -3 in all mealybug specimens collected from both the Hawaiiana cultivar and the MD-2 hybrid tested, with these PMWaVs showing a 99% sequence identity with others recently reported in Peru. Therefore, D. brevipes is a host and probable vector of PMWaV-1, -2, and -3 for the cultivar Hawaiiana and the hybrid pineapple MD-2 in Satipo and Chanchamayo, Peru. Based on these findings and observations of crop management strategies in these provinces, we recommend integrated management practices to control this pest.

The tomato leafminer, Phthorimaea absoluta (synonym Tuta absoluta Meyrick, 1917), is a transboundary plant pest that poses a serious threat to global tomato cultivation and production, with significant negative social and environmental impact from increased insecticide usage for its management. We present three P. absoluta draft mitochondrial genomes (mitogenomes) from Malawi and South Africa, thereby increasing the mitogenome resources for this invasive agricultural pest. Comparative analysis with Spain, China, and Kenya samples revealed at least seven maternal lineages across its current invasive ranges, supporting multiple introductions as a major factor for the spread of invasive populations. Mitogenome results therefore identified unexpected diversity as compared to the use of the partial mitochondrial cytochrome oxidase subunit I (mtCOI/cox1) gene marker for the inference of P. absoluta invasion biology. The whole-genome sequencing approach further identified alternative mitochondrial DNA (mtDNA) gene regions necessary to improve diversity estimates, and enables concurrent characterisation of insecticide resistance genes. Characterisation of the VSSG (Para) and AChE-1/ace-1 gene profiles that underpin pyrethroid and organophosphate (OP) resistances, respectively, confirmed co-introductions of pyrethroid and OP resistance genes into Malawian and South African populations. Our study highlights the need for additional P. absoluta mitogenome resources, especially from native populations that is needed for more accurate interpretations of introduction pathways and the development of future sustainable management strategies.

The gut pH plays crucial roles in diet preference, habitat choice, insect fitness, and insect-microbial relationships. It significantly impacts enzyme activity efficiency, as well as the internalisation and efficacy of pesticides. Without a comprehensive understanding of the gut environment, potential pest management strategies cannot be fully optimised.

This study investigates the gut pH of the globally invasive pest insect Western flower thrips Frankliniella occidentalis, and the effect its Gram-negative symbiotic gut bacterium BFo2 has on pH modulation. Indicator dyes were fed to F. occidentalis and the gut pH was found to vary between 6 and 7. In general, the larval and adult guts appear to have a pH of between 6 and 6.5; however, the posterior gut of some adults appears to be closer to 7. This almost neutral pH offers a favourable environment for the neutrophilic symbiotic BFo2. The ability of BFo2 isolates to buffer pH towards neutral was also observed during in vitro culture using broths at different pH values.

This paper also discusses the implications of this gut environment on dsRNAi delivery. By laying the foundation for understanding how gut pH can be leveraged to enhance current pest management strategies, this study particularly benefits research aimed at optimising the delivery of lethal dsRNA through symbiont-mediated RNAi to Western flower thrips in pest management programs.

Aphids are important pests of cereal crops and cause economically significant damage through direct feeding and the transmission of plant viruses. In Europe, the aphid species of greatest concern are the grain aphid (Sitobion avenae Fabricius) and the bird cherry-oat aphid, (Rhopalosiphum padi Linnaeus). Often, cereal crops are dominated by a small number of prolific clonal populations and these populations can differ in phenotypic traits of agricultural importance. There are two heritable factors that influence aphid phenotype: aphid genetic diversity and the presence of endosymbionts.

Here, multiple cereal aphid populations are used to determine how heritable factors influence aphid phenotype. Several agriculturally important phenotypic traits are examined, and both endosymbiont- and genotype-derived phenotypes are identified. For S. avenae, aphid genotype influences all phenotypic traits assessed, and association with the facultative endosymbiont Regiella insecticola influences alate morph production with co-infection of R. insecticola and Fukatsuia symbiotica increasing reproductive output. For R. padi, adult aphid morph (apterous or alate) is the key driver behind reproductive output, with a genotype × morph effect also found to influence development time.

Overall, these results provide insight into the biological drivers behind phenotypic diversity in agriculturally important aphid species. Being able to associate heritable factors with key phenotypes can generate biological insights into the processes underpinning the dominance of specific aphid clones and can be used to develop pest and disease management strategies based around the phenotypic risk of the aphid populations present.

Coccygidium luteum (Hymenoptera: Braconidae), a solitary larval parasitoid, is associated with the fall armyworm (FAW), in Africa. However, there is very limited information on reproductive biology, and other biological parameters that influence its life strategies. We conducted laboratory experiments to gain new insights into the biology of C. luteum reared on FAW as the host. Host age preference, reproductive biology, lifetime fecundity, life cycle, and adult longevity were studied under laboratory conditions of 28 ± 1°C and 70 ± 3% relative humidity. This study revealed that C. luteum prefer early (1st–3rd) instars of FAW for oviposition. The maximum parasitism rate was 80% at second instar larvae. A mean pre-oviposition period of 0.38 ± 0.51 days, oviposition period of 5.13 ± 0.64 days, and no post-oviposition period were observed. The mean lifetime parasitism rate of FAW larvae by female C. luteum was 49 ± 24. Longevity of unmated C. luteum was 14.44 ± 1.43 days for males and 12.83 ± 1.12 days for females. Mated ovipositing females lived for 7 days. Mean female and male progenies per adult female C. luteum was 28.11 ± 8.18 and 39.89 ± 4.76 respectively, with an overall sex ratio of 1.42 at 28 ± 1°C using second instar larvae. Total life cycle from oviposition to adult emergence was 23 ± 1 days. This study provides the basic information about C. luteum that could be utilised for mass rearing of this parasitoid under an augmentative biological control of FAW programme.

The relationships between the Japanese beetle (JB) Popillia japonica Newman, 1841 and the grapevine agroecosystem were investigated in Piedmont in 2020 and 2021, to assess the impact of the species and its distribution within vineyards in relation to the proximity of environmental risk factors. Grubs were sampled by soil coring in the inter-rows of vineyards, whereas both adult beetles and defoliation were counted directly on grapevine plants. The presence of spatial autocorrelation was assessed and the influence of environmental variables (distance from woodlands, meadows and the margin of the vineyard, soil parameters, year of sampling, and year of first detection of the JB) was evaluated through generalized linear mixed models. Beetles and defoliation were more clustered at the edges of vineyards, whereas grubs were localized in few hot spots, generally close to meadows. Spatial autocorrelation was weaker for grubs with respect to adults and defoliation. Grub density depended on distance from meadows, and partially on soil features. Adults abundance was influenced by the proximity to meadows, woodlands, and their presence was clustered at the margin of vineyards. The JBs seem to rely on grapevine mainly as a food source rather than a reproductive site, preferring meadows for egg-laying: therefore, pest management in vineyards should be more focused on adult beetles rather than larvae in the vineyard inter-rows.

We evaluated the lethal and sublethal effects of two novel Betaproteobacteria-based insecticides (Burkholderia spp. strain A396 as Venerate® XC; Chromobacterium subtsugae strain PRAA4-1 as Grandevo® WDG) and two neem-based insecticides (1.2% azadirachtin A and B as Azatrol and 3% azadiractin as Molt-X) on the cotton aphid, Aphis gossypii, and its natural enemy, Coccinella septempunctata. Aphids were given both residual and direct treatments, i.e. exposed to residues applied by leaf dipping, or by spraying the insects and foliage, while the predator was treated directly with insecticides. Well-established spirotetramat (Movento® 240 SC) was used as standard due to its effectiveness against a wide range of pests, its unique mode of action, and its systemic properties. All insecticides were effective against aphid mostly in concentration-dependent manner, as do exposure time, but at different magnitudes. Spirotetramat and Azatrol induced the highest toxicity to adult aphids, while spirotetramat and Molt-X were more noxious to aphid nymphs. C. subtsugae and Burkholderia were less effective, inducing only moderate levels of aphid mortality. Azatrol and spirotetramat were more detrimental to the fecundity of aphid compared to other products. Insecticides significantly increased the development time of nymphs surviving exposure to insecticides, except Burkholderia. Azatrol were more destructive to eggs, larvae and adult of Coccinella septempunctata, together with spirotetramat for young larvae and adults, relative to other treatment. The development time of predator larvae remained unaffected by treatment. New Betaproteobacteria- and neem-based insecticides except Azatrol seem to be a promising tool to suppress population of Aphis gossypii and integrate pest management programmes.

The canopy of forests as the ‘last biotic frontier’ has often been neglected in insect biodiversity studies because it is harder to access compared to the understorey, even in relatively well-known temperate ecosystems. We investigated the diversity, abundance, and body size patterns of macromoths (Lepidoptera) in the canopy and understorey in a central European deciduous forest. We collected moths at two sites during 19 trapping nights and three lunar phases between July and September 2021 using a weak ultraviolet light emitting diode (LED) lamp (LepiLED mini). Overall, we captured 4368 individuals (165 species) from 11 families. Based on a number of metrics, richness and diversity was significantly lower in the canopy than in the understorey. Non-metric multidimensional scaling ordinations show that communities largely overlap, but the proportion of species that only occur in the understorey was higher. While Noctuidae and Erebidae species were abundant in both strata, Geometridae species were most frequently observed in the understorey. We identified 16 indicator species for the understorey but only three for the canopy. Forewing length of moths in the canopy was on average 1.7 mm longer than of those in the understorey. Overall, the understorey is far more important for moths than the canopy in a temperate forest. The canopy is dominated by fewer and larger species and probably has a higher proportion of dispersers.

In December 2017 the Venetian Region (local Authority), financed the creation of the Operational Group (OG) ‘Serinnovation’, within the framework of the Rural Development Plan supported by the European Community. The OG aims at coordinating and spreading innovation in sericulture through mechanisation of processes and centralisation of some rearing steps, the use of waste as by-products and traceability to promote local productions. The project acts on perceived quality by increasing the added value, through production cost efficiency, and on the recovery of the waste material for further applications (circular economy). The final target was to develop a niche-process to obtain traceable ‘Made-in-Italy’ silk for the luxury market and non-textile applications. A first strategy to increase the efficiency of the process was to build an automatic leaf cutting machine to prepare the feed for the first three instars of the silkworm (Bombyx mori Linnaeus). This new machine – based on a patent – was validated through several tests and compared with the cutting system previously used. The study was completed by a bioassay of production and survival rate associated with the introduction of this innovation. The results showed that labour saving is in the order of 10% compared to a semi-manual process, the leaf quality is not affected, survival of larvae and silk production are not significantly different from the control. This methodology is proposed as a study case for other similar mechanisation processes in entomological production, as the impact of innovations on insect physiology should be carefully considered.

One of the most prominent problems related to biological invasions is the variation of local species composition, which often leads to ex novo interspecific interactions. Here, we explored and analysed the native species composition of gall inducers and their associated parasitoids and inquilines in Spanish areas invaded by Dryocosmus kuriphilus Yasumatsu 1951 (Hymenoptera: Cynipidae), an invasive pest of chestnut trees. After a quantitative description of these species' assemblages, we analysed through bipartite networks the level of the trophic specialisation of parasitoids and inquilines when considering either the host taxonomic identity, the host plant species or the host gall morphological type. We sampled galls of D. kuriphilus and native species of Cynipidae in different Spanish areas, including those where the exotic parasitoid Torymus sinensis Kamijo 1982 (Hymenoptera: Torymidae) had been released for D. kuriphilus biological control. The results indicate that the native parasitoids recruited by D. kuriphilus come almost exclusively from native communities on Quercus galls, except for one species from Rosa. Galls of D. kuriphilus had the second most diverse species composition; despite this species assemblage arose ex novo in less than a decade. The bipartite networks resulted more specialised when considering host plant taxa than when gall types and the host taxa were accounted. In such trophic webs, there were few parasitoid/inquiline specialist and many generalist species, which agrees with the rapid recruitment by D. kuriphilus. Higher parasitoid species richness in D. kuriphilus galls is likely due to their being a largely unexploited available resource for the native natural enemies of cynipid wasps.

Triatomines (Hemiptera: Heteroptera: Reduviidae) are hematophagous insects, well-known for their vectorial role in transmitting Trypanosoma cruzi Chagas (Kinetoplastida: Trypanosomatidae) parasites, the etiological agent of Chagas disease. Trapping these insects would limit human-triatomine interaction and, thus, control the disease. In this context, there is a critical need for effective lures to control triatomines. Through double-choice bioassays, we investigated the preference of Triatoma infestans Klug, T. pallidipennis Stal, and Rhodnius prolixus Stal triatomines for: (a) volatiles from fermented products (various fermentation types and substrates) and (b) commercial insect lures. Furthermore, we identified the chemical composition of these volatiles through headspace collection using Solid Phase Micro Extraction coupled with Gas Chromatograph-Mass Spectrometer (HS-SPME-GC-MS). Volatiles from lactic fermentation and certain fermented fruits, along with commercial lures, attracted triatomines, while other products exhibited possible repellent or dislodging properties. These findings hold promise for the control of triatomines and, ultimately, Chagas disease.