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Canola (Brassica napus L. and B. rapa L. [Brassicales: Brassicaceae]) is a major oilseed crop grown globally as a source of vegetable oil, animal feed and biofuel feedstock. The global demand for canola oil as a biofuel feedstock has increased due to recent regulations in the European Union, United States, and Canada. In North America, canola production is centered on the northern Great Plains where it is challenged by two highly destructive flea beetle species, the crucifer (Phyllotreta cruciferae Goeze, 1777) and the striped (Phyllotreta striolata Fabricius, 1803) flea beetles. In the spring, adult P. cruciferae and P. striolata begin feeding on canola seedlings, creating a 'shot hole' appearance, which can reduce the plant's photosynthetic capacity leading to uneven plant emergence and growth, reduced plant stand density, and reduced seed yield. Losses resulting from flea beetles are estimated in the tens of millions of dollars annually. At present, the principle means for flea beetle control are insecticides applied as systemic seed treatments and/or subsequent foliar sprays. The continued use of these products is being questioned due to environmental concerns and acquisition of resistance. As such, significant research effort is being directed toward the development of an integrated pest management system for these abundant and hard to manage pests of canola. Here, we review the ecology, pest status, and management of flea beetles in North America and discuss future research needed to promote flea beetle management and sustainable canola production. [ABSTRACT FROM AUTHOR]

Gastrolina depressa (Coleoptera: Chrysomelidae) has been found to damage many walnut plants in China. It prefers to feed on the annual leaves of an important economic plant, Pterocarya stenoptera (Fagales: Juglandaceae), and causes extensive cosmetic destruction, even plant death. Nevertheless, its biological characteristics are mostly unknown. In this study, we investigate the harmful and biological characteristics of G. depressa with different developmental stages. The results showed that G. depressa had four developmental stages: egg, larva (1st -3rd instar), pupa, and adult, the life history lasted nine days, with obvious overlapping generations. The food intake of the larvae increased with the increase of the instar, and the maximum food intake of the 3rd instar larvae was 448.19 mm2. The abdomen of the females was enlarged before oviposition, and the average number of eggs laid was 47.63 ± 13.53. Bioassay showed that there was no difference in the search time for the young (2.03, 1.25, 1.15, and 0.91 min) and old leaves (1.68, 1.15, 0.90, and 1.93 min) of P. stenoptera between 1st -3rd instar larvae and adults; the feeding preference of 1st -3rd instar larvae and adults for young leaves was higher than that to old leaves (23.33%, 26.67%, 33.33%, and 21.67%, respectively). The successful selection rates of 1st -3rd instar larvae and adults to young leaves (81.67%, 80%, 85.00%, and 70.00%, respectively) was higher than to old leaves (8.35%, 11.67%, 3.34%, and 11.67%, respectively). [ABSTRACT FROM AUTHOR]

Investigations of age‐based food conversion and utilization efficiencies in phytophagous insects are very few. Studies examining the effects of age, sex and mating status on biochemical assimilation of macronutrients by phytophagous insects are scarce as well. Hence, we designed the present study to evaluate the combined effect of age, sex and mating status on food consumption and utilization efficiencies, and the assimilation of macronutrients by the Parthenium beetle, Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae), on the invasive weed, Parthenium hysterophorus Linnaeus (Asterales: Asteraceae). We hypothesized that mated adults would consume and utilize more food than unmated adults, that assimilation of nutrients by old adults would be lower than young adults and that females would consume and utilize food more efficiently than males. However, our results revealed that as adults aged, their food consumption and utilization efficiencies decreased, and they assimilated less proteins and glucose in their body. Despite that, their mean body biomass and assimilation of triglycerides increased. While mated adults had higher food utilization efficiencies and increased assimilation of triglycerides and glucose, unmated adults assimilated more proteins. Females had higher food consumption rates and increased assimilation of nutrients, whereas males had higher food conversion efficiencies and growth rates. Furthermore, middle‐aged adults had higher food utilization efficiencies and they assimilated more nutrients than young and old adults. Our results therefore suggest compensatory feeding in adults of Z. bicolorata with ageing. We also recommend the release of more numbers of mated middle‐aged females to control P. hysterophorus in agro‐ecosystems. [ABSTRACT FROM AUTHOR]

Prey animals employ masquerade to avoid recognition by visual predators by developing a resemblance to inedible objects in their environment. Phytophagous flea beetles seem to resemble models of their own manufacture. While feeding they cause light- or dark-coloured hole-like damage on the leaves of their host plants that resembles the beetle's body in colour and size. Resemblance to the model and the frequency of the model can influence the efficiency of masquerade. To examine masquerade efficiency in light- and dark-coloured beetles, we evaluated their survival benefits from resembling feeding damage in the field. This was done by using two species of beetle of different colour as prey and a jumping spider as the predator. Dark-coloured species were more likely to avoid predation when they were placed on a background with damage similar in colour to their body, whereas increased survival was not recorded for light-coloured species. The extent of the feeding damage of 34 light- and dark-coloured species of beetle was compared. Variation in the extent of the damage was associated more with host plant taxa than beetle body colour. These results indicate that the efficiency of masquerade can vary among beetle species and/or phenotypes. [ABSTRACT FROM AUTHOR]

Morphological plasticity may be induced by altering host plants and commonly it is sex‐specific in phytophagous insects. It is hypothesized that stress in insects caused by a host shift leads to morphological changes and developmental destabilization, which may be identified by fluctuating asymmetry. We performed reciprocal transplant experiments in eight replicated populations of the seed beetle Acanthoscelides obtectus (Say) (Coleoptera: Chrysomelidae, Bruchinae) adapted to common bean (Phaseolus vulgaris L., Fabaceae) as its ancestral host and chickpea (Cicer arietinum L., Fabaceae) as a suboptimal host. Using methods of geometric morphometrics we assessed the effects of the short‐ and long‐term host shift on size and shape variation of beetles of both sexes. We also tested the hypothesis that fluctuating asymmetry is lower when the beetles develop within seeds of the ancestral host. Our results showed that females respond more plastically related to their body size and shape of the abdomen, particularly during a short‐term host shift, suggesting that females have a greater importance in maintaining the population on a new host. The level of fluctuating asymmetry is lowest in males that have evolved for generations on bean indicating that they have the most canalized development, so we suggested that symmetry in A. obtectus is maintained by sexual selection. Even if the beetles are adapted to a suboptimal host over many generations, they stabilize their development after returning to the ancestral host. Our work indicates that host shifts may change morphological aspects of the beetles in a sex‐specific manner and consequently influence their developmental trajectories. [ABSTRACT FROM AUTHOR]

The equilibrium of sex ratios in sexually reproducing species is often disrupted by various environmental and genetic factors, including endosymbionts like Wolbachia. In this study, we explore the highly female‐biased sex ratio observed in the flea beetle, Altica lythri, and its underlying mechanisms. Ancient hybridization events between Altica species have led to mitochondrial DNA introgression, resulting in distinct mitochondrial haplotypes that go along with different Wolbachia infections (HT1‐wLytA1, HT1*‐ uninfected, HT2‐wLytA2, and HT3‐wLytB). Notably, beetles with some haplotypes exclusively produce female offspring, suggesting potential Wolbachia‐induced phenomena such as feminization of genetic males. However, the observed female bias could also be a consequence of the ancient hybridization resulting in nuclear–cytoplasmic conflicts between introgressed mtDNA and nuclear genes. Through transcriptomic analysis and the program SEX‐DETector, we established markers for genotypic sex differentiation for A. lythri, enabling genetic sexing via qPCR. Our findings suggest that feminization of genetic males is contributing to the skewed sex ratios, highlighting the intricate dynamics of sex determination and reproductive strategies in this flea beetle. This study provides valuable insights into the dynamics of genetic conflicts, endosymbionts, and sex ratios, revealing the novel phenomenon of genetic male feminization in the flea beetle A. lythri. [ABSTRACT FROM AUTHOR]

Aim: Knowledge of taxonomy and species distributions in highly diverse lineages of invertebrates remains too incomplete for the study of biogeographical patterns at the global scale. This limits the understanding of processes leading to the formation and maintenance of boundaries between major biogeographical realms. Site‐based metagenomic approaches may provide an alternative source of data for inference of historical processes of in situ speciation and interchange among biogeographical regions. We applied the methodology to explore the historical biogeography of the Qinling Mountains at the boundary of the Oriental and Palaearctic regions. Location: The focal area in the Qinling Mountains; sites in Borneo, Panama, and Spain, representing the Oriental, Neotropical and Palaearctic faunas. Time Period: Contemporary. Major Taxa Studied: Chrysomelidae, a group of ~40,000 species with worldwide distribution. Methods: Mass‐trapped insects were subjected to deep Illumina DNA sequencing and mitochondrial genome assembly, followed by phylogenetic analysis and historical biogeographical inference on a dated tree. The methodology produced 622 mitogenomes (304 newly sequenced) each representing a morphologically distinct species. Results: Ancestral area reconstruction revealed that the Qinling fauna is a composite of distinct clades that, respectively, have Oriental or Palaearctic ancient origins, while in situ speciation and local clade formation were limited. The global diversity of Chrysomelidae consists of regionalised deep clades at the level of the major zoogeographic realms, which remain recognisable where these realms abut in the Qinling mountains. Yet, the Qinling fauna is clearly distinct from the source areas although local lineage ages are generally <20 Ma. Main Conclusions: The Qinling fauna is a composite of clades that have either Oriental or Palaearctic origin, indicating the important role of immigration at the realm boundary. Global site‐based phylogenetic analyses based on metagenomic sequencing can address previously intractable questions about the historical biogeography of poorly studied groups even without a fully developed taxonomy. [ABSTRACT FROM AUTHOR]

Simple Summary: Insect-specific negative-sense RNA viruses are widespread, exhibiting a diverse range of characteristics. Leaf beetles within the Chrysomelidae family, known for their chewing mouthparts, are significant agricultural pests. Despite this, reports of negative-sense RNA viruses in leaf beetles are scarce. In this study, we have identified two novel negative-sense RNA viruses in a globally distributed leaf beetle species, Aulacophora indica (Coleoptera, Chrysomelidae). The complete genomes of two insect-infecting viruses (ISVs) were successfully obtained through metatranscriptome analysis and rapid amplification of cDNA ends (RACE), named Aulacophora indica nyami-like virus 1 (AINlV1) and Aulacophora indica chu-like virus 1 (AIClV1). Phylogenetically, AINlV1 falls into an unclassified clade within the Nyamiviridae virus family, while AIClV1 is classified as a member of the Scarabeuvirus genus within the Chuviridae family. Both viruses exhibit typical genome structures associated with their respective families. Additionally, they activate small RNA interference responses, with virus-derived small RNAs (vsiRNAs) from AINlV1 and AIClV1 showing a consistent pattern peaking at 21 nucleotides, biased towards A/U at the 5′-terminal. Our study provides valuable insights into insect-specific viruses (ISVs) affecting leaf beetles. Herbivorous insects harbor a variety of insect-specific viruses (ISVs) some of which are considered to be valuable biological agents for potential applications in biological defense and control strategies. Leaf beetles with chewing mouthparts are particularly known for their capacity to disrupt plant tissue while feeding, often creating openings that can act as entry points for plant pathogens. In this study, we have identified two new negative-sense RNA viruses infecting the leaf beetle Aulacophora indica, an important member of the Chrysomelidae family. These recently discovered viruses belong to the viral families Nyamiviridae and Chuviridae and have been preliminarily named Aulacophora indica nyami-like virus 1 (AINlV1) and Aulacophora indica chu-like virus 1 (AIClV1), respectively. The complete genomic sequences of these viruses were obtained using rapid amplification of cDNA ends (RACE) techniques. Detailed analysis of their genomic structures has confirmed their similarity to other members within their respective families. Furthermore, analysis of virus-derived small interfering RNA (vsiRNA) demonstrated a high abundance and typical vsiRNA pattern of AINlV1 and AIClV1, offering substantial evidence to support their classification as ISVs. This research enhances our understanding of viral diversity within insects. [ABSTRACT FROM AUTHOR]

The turbulent Tertiary and Quaternary history of Europe and the Ponto-Caucasus has had a strong impact on its biota, resulting in unusual patterns of speciation, diversification, and dispersal. Our study reveals the Late-Tertiary diversification and biogeographic history of Mniophila , a Western Palaearctic endemic moss-inhabiting flightless flea beetle distributed across Europe and the Ponto-Caucasus. We assembled samples across the whole range of the genus except Crimea. Based on a molecular phylogenetic analysis, we found that the diversification of Mniophila started in the Balkan Peninsula, and was followed by at least two independent colonizations of other parts of Europe. The Ponto-Caucasian species are all descendants of a single colonization from the Balkans, followed by species' radiation. The Mniophila beetles are, therefore, one of the first-known cases of the colonization of the Caucasus from Europe. We integrated our DNA data with morphology, allowing us to uncover the cryptic diversity of Mniophila and to revise its European species. We describe Mniophila haveli sp. nov. from the Carpathians and Balkans, M. wroblewskii Wańkowicz, 1880 from Central Europe and the Balkans is restored as a valid species, and M. bosnica Apfelbeck, 1914 is newly recognized as a Dinaric endemic. We reveal an exceedingly large distribution range for M. muscorum (Koch, 1803), which is unusual for a flightless beetle. [ABSTRACT FROM AUTHOR]

Biological control practitioners are required to demonstrate that candidate agents are not only safe for release, but will establish widely in their new range with a significant impact on the target weed.We conducted this study in quarantine to provide insight into the impact and distribution of the root‐feeding flea beetle Heikertingerella sp. (Chrysomelidae), released in early 2023 against the invasive tree Tecoma stans (L.) (Bignoniaceae) in South Africa. We studied the effects of low and high beetle densities on plant growth and biomass, and F1 progeny production by the beetle.There were significant reductions in plant growth and biomass accumulation in the beetle‐exposed plants, relative to the controls. P1 adults damaged significantly more leaflets, with significantly higher F1 progeny production, at high beetle densities.The MaxEnt model predictions suggested that most of South Africa is climatically highly suitable for Heikertingerella sp., particularly along the southern and eastern coasts where the weed is most prevalent. Only the inland regions of the Northern Cape Province, depicting the driest and hottest part of the country where the weed does not occur, were predicted to be unsuitable for Heikertingerella sp. The beetle's thermal physiology, as determined by its critical thermal minimum and maximum temperatures and lower and upper lethal temperatures (LT50), suggests tolerance to temperature extremes in at least four of the eight provinces that fall within the range of T. stans in South Africa.Our results further justify the release of Heikertingerella sp. in areas predicted as suitable in South Africa. [ABSTRACT FROM AUTHOR]

Invasive alien species are one main driver of biodiversity loss and can cause severe economic costs. Effective management of such species requires early detection of colonising individuals, but this is often hampered by biological or economic constraints.Trachymela sloanei (Blackburn, 1896), an Australian Eucalyptus defoliator beetle, is an invasive alien species that has spread to the Americas, Asia and most recently Europe.We analyse the expansion of T. sloanei in the Iberian Peninsula both at regional and local scales, study its phenology and relative abundance, and explore the use of nest boxes for early detection.The species is spreading steadily, and the area potentially affected has increased dramatically in a few years. Both adults and larvae were observed between June and November, suggesting the occurrence of several overlapping generations. More than 300 individuals were found aggregated behind single nest boxes.We conclude that the installation and monitoring of nest boxes or similar structures (e.g., cork boards) can facilitate early detection of this species. [ABSTRACT FROM AUTHOR]

BACKGROUND: Transgenic crops producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) have been used to manage insect pests for nearly 30 years. Dose of a Bt crop is key to assessing the risk of resistance evolution because it affects the heritability of resistance traits. Western corn rootworm (Diabrotica virgifera virgifera, LeConte), a major pest of maize, has evolved resistance to all commercially available Bt traits targeting it, and threatens resistance to future transgenic traits. Past research shows the dose of Bt maize targeting western corn rootworm can be confounded by larval density‐dependent mortality. We conducted a 2‐year field study at two locations to quantify larval density‐dependent mortality in Bt and non‐Bt maize. We used these results to calculate dose for our method and compared it to three previously published methods. Additionally, adult emergence and root injury were analyzed for predicting initial egg density. RESULTS: Increased pest density caused greater proportions of larvae to die in Bt maize than in non‐Bt maize. All methods for calculating dose produced values less than high‐dose, and stochastic variation had the greatest impact on dose at high and low pest densities. Our method for calculating dose did not produce values positively correlated with pest density while the three other methods did. CONCLUSION: To achieve the most accurate calculation of dose for transgenic maize targeting western corn rootworm, density‐dependent mortality should be taken into account for both transgenic and non‐transgenic maize and assessed at moderate pest densities. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Insects mainly rely on innate immunity against pathogen infection. Plagiodera versicolora (Coleoptera: Chrysomelidae), is a worldwide leaf‐eating forest pest in salicaceous trees. However, the mechanisms behind the immunodeficiency pathway (IMD) remain poorly understood. RESULTS: In this study, we obtained a Relish gene from transcriptome analysis. Tissue and instar expression profiles were subsequently obtained using quantitative real‐time polymerase chain reaction analysis. The results showed that Relish has high expression levels in eggs, larvae and adults, and especially in fat bodies. Transcripts of the tested antimicrobial peptides (AMPs), defensin1, defensin2 and attacin2 were downregulated by dsRelish. Knockdown of Relish led to greater mortality in larvae after Staphylococcus aureus infection. In addition, we performed bacterial 16S ribosomal RNA‐based high‐throughput sequencing. The results showed that the relative abundance of some gut bacteria was significantly altered after dsRelish ingestion. CONCLUSION: This study provides a greater understanding of the IMD signaling pathway, facilitating functional studies of Relish in P. versicolora. Moreover, a genetic pest management technique might be developed using Relish as a lethal gene to control the pest P. versicolora. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Reproductive diapause serves as a valuable strategy enabling insects to survive unfavorable seasonal conditions. However, forcing insects into diapause when the environment is conducive to their well‐being can cause them to miss out on seasonal opportunities for reproduction. This outcome not only reduces insect populations but also minimizes crop losses caused by insect feeding. Therefore, altering the timing of diapause initiation presents a potential strategy for managing pests. In this study, we examined the possible role of the Insulin Receptor 1 (InR1) in controlling reproductive diapause entry in the male cabbage beetle, Colaphellus bowringi. RESULTS: Compared to short‐day (SD) conditions, long‐day (LD) conditions led to reproductive diapause of C. bowringi males, characterized by arrested gonad development, increased Triglyceride (TG) accumulation, and upregulated expression of diapause protein 1 and genes associated with lipogenesis and stress tolerance. Upon employing RNA interference to knock down InR1 under SD conditions, males destined for reproduction were compelled into diapause, evidenced by arrested gonadal development, accumulation of TG, and elevated expression of diapause‐related genes. Intriguingly, despite the common association of the absence of juvenile hormone (JH) with reproductive diapause in females, the knockdown of InR1 in males did not significant affect the expression of JH biosynthesis and JH response gene. CONCLUSION: The study highlight InR1 is a key factor involved in regulating male reproductive diapause in C. bowringi. Consequently, targeting insulin signaling could be a viable approach to perturb diapause timing, offering a promising strategy for managing pests with reproductive diapause capabilities. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Callosobruchus maculatus (Fabricius), also known as the cowpea beetle or pulse beetle, is the most important pest of stored cowpea. The beetle causes both qualitative and quantitative losses in the grains, all of which result in low crop yields. The objective of this work was to investigate the insecticidal effect of rose essential oil (REO) on adult Callosobruchus maculatus in terms of mortality and oviposition. In addition, the viable mesophilic aerobic bacteria of C. maculatus were evaluated, and surface molecular electrostatic potential (MEP) maps were examined to determine the interaction domains of the bioactive components of REO. The interaction mechanism between the AChE enzyme (PDB ID: 6XXY, 4EY6, 4EY7 and 6O4W) and the REO components was investigated using the molecular docking method. The highest mortality of 92.40 ± 0.03% was obtained at 16 μL within 72 h of exposure. Higher concentrations of the essential oil decreased the laying performance of C. maculatus. A significant decrease of 91.33% in the number of eggs laid was observed. Gas chromatography–mass spectrometry (GC/MS) results showed that the major constituents of Rosa damascena Miller essential oil (REO) were citronellol (46.15%), geraniol (16.19%), nonadecane (8.80%) and nerol (7.43%). Treatments of 4, 8, 12 and 16 μL of REO significantly reduced the viable mesophilic aerobic bacteria of C. maculatus samples compared with the control. It was found that the most effective binding was between the REO components and the 4EY7 protein, with binding energies ranging from −6.9 to −8.9 kcal/mol. Although the major component of REO was citronellol (46.15%), the best interaction was observed with farnesol isomer B (0.80%). Overall, these results suggest that REO has the potential to control C. maculatus as an environmentally friendly alternative to synthetic pesticides. [ABSTRACT FROM AUTHOR]

Myochrous armatus Baly, 1865 (Coleoptera: Chrysomelidae) has expanded its occurrence significantly into soybean‐growing areas of Brazilian Cerrado and became an important early‐season soil pest. Experiments were performed under field conditions from 2020 to 2023 to assess several aspects: (1) population behaviour over crop season and offseason; (2) day/night behaviour during the early stages of soybean plants and (3) injury to plants and potential damage to soybean yield to establish the Economic Injury Level (EIL). Adults of the M. armatus population presented a season‐long abundance during the specific period from late October to January, with major captures in November and December (end of Spring), either inside or on the edge of soybean fields. Weeds and volunteer plants of corn and cotton hosts adults and eggs. These findings suggest an univoltine life cycle. Behavioural assessments revealed that M. armatus does not exhibit a specific day, night or crepuscular behaviour, performing deeds at any time. The majority of insects (40% to 70%) were found in the soil throughout the day and night. Adults feed on soybean plants by scraping or cutting the stem, cotyledon, petiole and apical sprouting. Their preference is initially for the stem and cotyledon (up to 14 days after emergence), and later for the petiole (after 21 days of emergence). After 7 days of coexistence at V1‐V3 soybean stages, we observed a potential yield reduction of 35% for each insect per plant. Dynamic EIL estimations are between 0.4 and 1.9 adults per row metre, depending on the grower productivity expectation, control costs and soybean market value. Our results are fundamental for establishing Integrated Pest Management for M. armatus in soybean and other crop systems. [ABSTRACT FROM AUTHOR]

Plants of the Meliaceae family have long attracted researchers' interest due to their various insecticidal activities, with triterpenes being the main active ingredients. In this paper, we discuss 93 triterpenoids with insecticidal activity from 37 insecticidal plant species of 15 genera (Munronia, Neobeguea, Pseudocedrela, Nymania, Quivisia, Ruagea, Dysoxylum, Soymida, Lansium, Sandoricum, Walsura, Trichilia, Swietenia, Turraea, and Xylocarpus) in the family Meliaceae. Among these genera, Trichilia deserves further research, with twelve species possessing insecticidal activity. The 93 insecticidal molecules included 27 ring-seco limonoids (comprising 1 ring A-seco group chemical, 1 ring B-seco group chemical, 5 ring D-seco group chemicals, 14 rings A,B-seco group chemicals, 5 rings B,D-seco group chemicals, and 1 rings A,B,D-seco group chemical), 22 ring-intact limonoids (comprising 5 cedrelone-class chemicals, 6 trichilin-class chemicals, 7 havanensin-class chemicals, 2 azadirone-class chemicals, 1 vilasinin-class chemical, and 1 other chemical), 33 2,30-linkage chemicals (comprising 25 mexicanolide-class chemicals and 8 phragmalin-class chemicals), 3 1,n-linkage-group chemicals, 3 onoceranoid-type triterpenoids, 2 apotirucallane-type terpenoids, 2 kokosanolide-type tetranortriterpenoids, and 1 cycloartane triterpene. In particular, 59 molecules showed antifeedant activity, 30 molecules exhibited poisonous effects, and 9 molecules possessed growth regulatory activity. Particularly, khayasin, beddomei lactone, 3β,24,25-trihydroxycycloartane, humilinolides A–E and methyl-2-hydroxy-3β-isobutyroxy-1-oxomeliac-8(30)-enate showed excellent insecticidal activities, which were comparable to that of azadirachtin and thus deserved more attention. Moreover, it was noteworthy that various chemicals (such as 12α-diacetoxywalsuranolide, 11β,12α-diacetoxycedrelone, 1α,7α,12α-triacetoxy-4α-carbomethoxy-11β-hydroxy-14β,15β-epoxyhavanensin, and 11-epi-21-hydroxytoonacilide, etc.) from Turraea showed excellent insecticidal activity. Specially, the insecticidal activity of khayasin from Neobeguea against the coconut leaf beetle were similar to that of rotenone. Therefore, it was a promising candidate insecticide for the control of the coconut leaf beetle. [ABSTRACT FROM AUTHOR]

To be effective, a biocontrol agent must survive and persist in the same habitat as the target species and reduce target population growth. When multiple biocontrol agents are used against a single invasive species, they may each perform better under a subset of the habitat in which the target lives. This complementarity allows for a more consistent level of control and a higher resilience to environmental variability. Two species that feed on the same plant tissues would compete, but niche partitioning in the native range may be replicated when both species are introduced to the invasive range. When biocontrol agents are released, they may self‐sort to perform best in their respective niches. We hypothesized that two biocontrol agents—Scotch broom seed beetle, Bruchidius villosus (Fabricius) (Coleoptera: Chrysomelidae) and Scotch broom seed weevil, Exapion fuscirostre (Fabricius) (Coleoptera: Brentidae)—that both feed on seeds of the invasive legume Scotch broom, Cytisus scoparius L. Link (Fabaceae), would be impacted differently by different weather conditions and plant traits, and would show different success rates at field sites with different conditions. We used a 5‐year study to reveal that the two biocontrol agents are not uniformly distributed in the field and that weather and plant factors influence their success. We confirmed that weather conditions of the previous year influenced biocontrol agent attack rate and found that weather patterns at a field site may predict the impact of each biocontrol agent. [ABSTRACT FROM AUTHOR]

Simple Summary: The flea beetle Asiophrida xanthospilota (Baly, 1881) is a serious forest pest specifically damaging the common smoketree Cotinus coggygria. To understand how this beetle sees the world, we used scanning electron microscopy, transmission electron microscopy, micro-computed tomography, and three-dimensional reconstruction to investigate the external morphology and internal ultrastructure of the compound eye. The examination showed that of Asi. xanthospilota has apposition eye like other leaf beetles, consisting of a subplano-convex cornea, an acone of four cone cells, eight retinular cells along with an open rhabdom, as well as two primary pigment cells and about 23 secondary pigment cells. Interestingly, retinular cell 8 does not contribute to the rhabdom. We also investigated the spectral sensitivity by electroretinogram tests and phototropism experiments. Electroretinogram tests showed that Asi. xanthospilota exhibits the strongest sensitivity to blue and green lights but the weakest to red light. Phototropism experiments also revealed that this beetle has the strongest reaction to blue light. In this study, the morphology and ultrastructure of the compound eye of Asi. xanthospilota were examined by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), micro-computed tomography (μCT), and 3D reconstruction. Spectral sensitivity was investigated by electroretinogram (ERG) tests and phototropism experiments. The compound eye of Asi. xanthospilota is of the apposition type, consisting of 611.00 ± 17.53 ommatidia in males and 634.8 0 ± 24.73 ommatidia in females. Each ommatidium is composed of a subplano-convex cornea, an acone consisting of four cone cells, eight retinular cells along with the rhabdom, two primary pigment cells, and about 23 secondary pigment cells. The open type of rhabdom in Asi. xanthospilota consists of six peripheral rhabdomeres contributed by the six peripheral retinular cells (R1~R6) and two distally attached rhabdomeric segments generated solely by R7, while R8 do not contribute to the rhabdom. The orientation of microvilli indicates that Asi. xanthospilota is unlikely to be a polarization-sensitive species. ERG testing showed that both males and females reacted to stimuli from red, yellow, green, blue, and ultraviolet light. Both males and females exhibited strong responses to blue and green light but weak responses to red light. The phototropism experiments showed that both males and females exhibited positive phototaxis to all five lights, with blue light significantly stronger than the others. [ABSTRACT FROM AUTHOR]

Simple Summary: Bean leaf beetles (BLBs) are significant pests in Uganda, damaging crops such as beans and cowpeas, leading to substantial yield losses. They exhibit preferential feeding behaviour, targeting specific crops over others. Understanding these preferences can form the basis for identifying a potential trap crop that can be used to manage the pest at a low cost in a sustainable manner. A field study was conducted to determine the feeding preference of BLBs on various host crops among those commonly cultivated in Uganda, across different locations and seasons. This study was conducted in Arua and Lira districts in the first and second rainy seasons of 2018. Seven BLB host crops, i.e., common bean, cowpea, greengram, soybean, groundnuts, okra and roselle (locally known as malakwang), were selected for the study. The results showed that cowpea exhibited the highest abundance of BLBs among all crops and it had a high amount of foliar damage as well. Thus, it was selected as the most preferred host crop and can be recommended as a trap crop for managing Ootheca spp. With respect to locations and seasons, the pest was more abundant in Arua than in Lira and more abundant in 2018A than 2018B across all locations. The bean leaf beetle (BLB) (Ootheca spp.) is a polyphagous pest causing significant yield losses in Uganda, particularly in the Northern and Eastern regions on various hosts plants. Despite its polyphagous behaviour, the BLB exhibits preferential feeding, offering an opportunity for targeted pest management. This study explored its feeding preferences across seven crops: common bean, cowpea, greengram, okra, roselle (malakwang), groundnuts, and soybean. This study was conducted in Arua and Lira districts using a randomized complete block design for two rainy seasons (2018A and 2018B). The results showed significant differences in BLB abundance and foliar damage among host crops, locations, days after planting and seasons. Cowpea was the most preferred crop while groundnuts was the least preferred. Therefore, cowpea can be recommended for use as a trap for managing Ootheca spp. in gardens where it is not the main crop. There was a higher pest abundance in Arua than in Lira. There was also a higher pest abundance in 2018A than in 2018B. These findings highlight the importance of understanding BLB's feeding preferences for implementing effective IPM strategies, emphasizing the potential role of trap cropping, especially with cowpea, to minimize BLB damage in resource-constrained agricultural settings. [ABSTRACT FROM AUTHOR]

Herbivorous insects generally choose host plants that optimize their growth. However, many specialists choose chemically defended host plants that slow their growth, prioritizing protection from natural enemies.Invasive specialist herbivores may have an added advantage in their non‐native range where they lack co‐evolved specialist natural enemies, in addition to being unpalatable to generalist predators.Here, we explore the diet preferences of the invasive yellowmargined leaf beetle, Microtheca ochroloma and those of native natural enemies. We measured M. ochroloma preferences among six Brassica cultivars varying in glucosinolate concentrations.In both field and laboratory experiments, M. ochroloma preferred the relatively less defended host plants, mizuna and Chinese cabbage. M. ochroloma grew quickest on mizuna.Generalist predators also preferred to eat M. ochroloma larvae that had been fed mizuna in choice trials, yet in the field, predatory insects were least commonly found on mizuna, and most commonly found on plants dominated by native herbivores.M. ochroloma consumes plants that increase their susceptibility to predators, but predation pressure in the field appears to be generally low. Our results suggest that invasive specialist herbivores may prioritize growth over protection against natural enemies.Weak top‐down regulation of specialist herbivore invaders might enable them to exploit less‐defended host plants in their novel range that facilitate faster growth and exacerbate crop damage. Invasive pests may be more effectively managed by leveraging plant preferences in the novel host range in trap crop systems. [ABSTRACT FROM AUTHOR]

South Pacific archipelagos are central in the biogeographic debate on the relative importance of vicariance and dispersal in shaping the distribution of species. However, each taxonomic group was subject to different processes and histories, and here, we reveal the historical biogeography of the diverse Eumolpinae leaf beetles, widely distributed in the region. Extensive taxon sampling focusing on South Pacific Eumolpinae was used to infer the first molecular phylogeny of the group using three single‐copy protein‐coding nuclear and two mitochondrial markers. Upon assessing the clade of interest for lineage‐specific variation in substitution rates, the age of the most recent common ancestors was estimated using out‐group calibration and multi‐gamma site models (MGSMs). Biogeographic analyses used standard event‐based inferences also incorporating phylogenetic uncertainty. Zealandian Eumolpinae are monophyletic and appear to have split from their global relatives in the transition from the Cretaceous to the Paleogene. Variation in the rates of molecular evolution affected the in‐group stem branch, with a significant drop in the substitution rate, and the MGSM correction recovered the crown age of Zealandian Eumolpinae during the Late Eocene–Oligocene transition. Biogeographic inference resolved the origin of the radiation in New Caledonia, favouring a null model without island age constraints, and repeated dispersal events to the other islands, including three independent but synchronous colonisations of New Zealand during the Miocene. New Caledonia, with a highly diverse Eumolpinae fauna of uncertain origin, acted as a hub and pump of biodiversity of these beetles in the entire South Pacific region, sending migrants to other islands through long‐distance dispersal with lineages establishing when land became available. [ABSTRACT FROM AUTHOR]

Bruchidius siliquastri Delobel, 2007, a chrysomelid species presumably of East Asian origin, is recorded for the first time in Greece. It is regarded as an invasive species in Europe that feeds on the seeds of Cercis siliquastrum L. (Fabaceae). The species distribution and ecology are briefly discussed. An additional record of Bruchidius terrenus (Sharp 1886) in Greece is also provided.

This study focuses on experimental testing of the contamination hypothesis and examines how the contamination of insect adhesive pads with three-dimensional epicuticular waxes of different plant species contributes to the reduction of insect attachment. We measured traction forces of tethered Chrysolina fastuosa male beetles having hairy adhesive pads on nine wax-bearing plant surfaces differing in both shape and dimensions of the wax structures and examined insect adhesive organs after they have contacted waxy substrates. For comparison, we performed the experiments with the same beetle individuals on a clean glass sample just before (gl1) and immediately after (gl2) the test on a plant surface. The tested insects showed a strong reduction of the maximum traction force on all waxy plant surfaces compared to the reference experiment on glass (gl1). After beetles have walked on waxy plant substrates, their adhesive pads were contaminated with wax material, however, to different extents depending on the plant species. The insects demonstrated significantly lower values of both the maximum traction force and the first peak of the traction force and needed significantly longer time to reach the maximum force value in the gl2 test than in the gl1 test. These effects were especially pronounced in cases of the plant surfaces covered with wax projections having higher aspect ratios. The data obtained clearly indicated the impact of waxy plant surfaces on the insect ability to subsequently attach to the clean smooth surface. This effect is caused by the contamination of adhesive pads and experimentally supports the contamination hypothesis.

A new species, Podontia rustiai Calcetas and Staines (Coleoptera: Chrysomelidae: Galerucinae: Alticini) in the Philippines, is described. The species Podontia flava Baly, 1865 is very similar and known from Borneo (Sarawak, Sabah) and Brunei is redescribed, and the introduced Podontia quatuordecimpunctata (L., 1767) is contrasted and compared. However, the endophallic median sclerite of the paramere of the male genitalia in P. flava is whip-like and apically tapered, whereas it is shield-like and apically rounded in P. rustiai new species. A key to the genus Podontia in the Philippines and Sarawak is provided. [ABSTRACT FROM AUTHOR]

The Colorado potato beetle (CPB), Leptinotarsa decemlineata, poses a significant threat to potato crops globally and has developed resistance to numerous insecticides. Entomopathogenic nematodes (EPNs), from the genera Steinernema and Heterorhabditis, are promising biocontrol agents. This study aimed to identify the bacterial symbionts of ten native EPN isolates, evaluate the efficiency of cell free supernatants (CFSs) from their symbiotic bacteria against different developmental stages of CPB, and determine the effect of these CFSs on CPB developmental stages and lifespan. The recA gene region was utilized to determine the symbiotic bacteria of ten local EPNs. CFSs from these bacteria were applied orally and through contact to CPB's various developmental stages (L1/L2, L3/L4 larval stages, and adults). Mortalities, developmental transition times, and lifespans of adults were observed. The CFSs showed significant toxicity to CPB, with higher efficiency against young larvae. The CFSs exhibited cumulatively lethal effects over time, particularly on L1/L2 larval stages. CFSs from X. bovienii exhibited the highest efficacy. In all cases, where larvae received CFSs orally or by contact, they failed to develop into pupae and adults. In contrast, the transition periods of old larvae to pupal and adult stages were comparable to those of the control group. Lifespans of adults differed based on bacterial isolates and application methods. This study shows the potential efficacy of CFSs from Xenorhabdus and Photorhabdus as biocontrol agents against CPB, particularly in its young larval stages. Further research is needed to unravel the mechanisms behind these effects and examine the impact on CPB mating and oviposition behaviors. [ABSTRACT FROM AUTHOR]

In this study, a total of 12 different fungal isolates were obtained from two different Colorado potato beetle (CPB) populations to identify a new effective agent to control L. decemlineata, which has developed resistance to many chemicals. The isolates were defined as Beauveria bassiana based on the ITS1-5.8S-ITS2, EF1-α, RPB1, and Bloc gene sequences. Under laboratory conditions, all isolates were pathogenic, but their virulence was different on larvae and adults. LdA-1 was the most virulent isolate with a mortality of 80% in larvae and 50% in adults. The LC50 value of this isolate was determined to be 0.2×106 and 0.17×108 conidia/ml for larvae and adults, respectively. Based on these results, LdA-1 isolates were used for mycoinsecticide development. Conidia were produced by solid-state fermentation using rice as a substrate. The conidia were formulated as oil-in-water emulsions and their efficacy was evaluated. The efficacy of the oil-based formulation against CPB larvae and adults was tested on eggplant in pot experiments. The new oil-based product caused 100% and 97% mortality on larvae and adults, respectively, at 1×108 conidia/ml. The LC50 value of our formulation for larvae and adults was calculated to be 1.2×106 and 0.2×107 conidia/ml, respectively. These results highlight that this formulation could be a suitable product for CPB control instead of conventional synthetic insecticides. [ABSTRACT FROM AUTHOR]

Alternanthera philoxeroides (Amaranthaceae), commonly known as alligator weed, is a globally invasive and detrimental perennial weed. Agasicles hygrophila serves as an important biocontrol agent for alligator weeds. However, during mid-summer, when temperatures increase, A. hygrophila populations experience a significant decline, leading to ineffective weed control. This study has examined the impact of periodic heat events on the reproduction and survival of A. hygrophila females and males using various mating combinations and durations of temperature treatments. The results demonstrated significant effects on all of the studied parameters across mating combinations when compared with the control. Under the same temperature combination, the fecundity and survival rates of females, as well as the egg-hatching rate, decreased significantly with increasing repeated heat exposure. Furthermore, the egg-hatching rate varied significantly among different temperatures and time-interval combinations. In addition, the females displayed greater sensitivity to heat stress than males in terms of fecundity. These findings enhance our understanding of A. hygrophila population dynamics during summer and provide insights into the release of biocontrol agents in diverse regions with varying climates. [ABSTRACT FROM AUTHOR]

Gregarines are usually classified as parasites, but recent studies suggest that they should be viewed on a parasitism-mutualism spectrum and may even be seen as part of the gut microbiota of host insects. As such, they may also impact the consumption of their hosts and/or be involved in the digestion or detoxification of the host's diet. To study such effects of a gregarine species on those traits in its host, the mustard leaf beetle (Phaedon cochleariae) was used. This beetle species feeds on Brassicaceae plants that contain glucosinolates, which form toxic compounds when hydrolyzed by myrosinases. We cleaned host eggs from gametocysts and spores and reinfected half of the larvae with gregarines, to obtain gregarine-free (G-) and gregarine-infected (G+) larvae. Growth and food consumption parameters of these larvae were assessed by rearing individuals on watercress (Nasturtium officinale, Brassicaceae). A potential involvement of gregarines in the glucosinolate metabolism of P. cochleariae larvae was investigated by offering G- and G+ larvae leaf discs of watercress (containing mainly the benzenic 2-phenylethyl glucosinolate and myrosinases) or pea (Pisum sativum, Fabaceae, lacking glucosinolates and myrosinases) treated with the aliphatic 4-pentenyl glucosinolate or the indole 1-methoxy-3-indolylmethyl glucosinolate. Larval and fecal samples were analyzed via UHPLC-QTOF-MS/ MS to search for breakdown metabolites. Larval development, body mass, growth rate and efficiency to convert food into body mass were negatively affected by gregarine infection while the pupal mass remained unaffected. The breakdown metabolites of benzenic and aliphatic glucosinolates were conjugated with aspartic acid, while those of the indole glucosinolate were conjugated with glutamic acid. Gregarine infection did not alter the larvae's ability to metabolize glucosinolates and was independent of plant myrosinases. In summary, some negative effects of gregarines on host performance could be shown, indicating parasitism. Future studies may further disentangle this gregarine-host relationship and investigate the microbiome potentially involved in the glucosinolate metabolism. [ABSTRACT FROM AUTHOR]

Introduction: DNA barcoding in insects has progressed rapidly, with the ultimate goal of a complete inventory of the world's species. However, the barcoding effort to date has been driven by a few national campaigns and leaves much of the world unsampled. This study investigates to what degree the current barcode data cover the species diversity across the globe, using the leaf beetle family Chrysomelidae as an example. Methods: A recent version (June 2023) of the Barcode-of-Life database was subjected to test of sampling completeness using the barcode-to-BIN ratio and sampling coverage (SC) metric. All barcodes were placed in a phylogenetic tree of ~600 mitochondrial genomes, applying phylogenetic diversity (PD) and metrics of community phylogenetics to national barcode sets to test for sampling completeness at clade level and reveal the global structure of species diversity. Results: The database included 73342 barcodes, grouped into 5310 BINs (species proxies) from 101 countries. Costa Rica contributed nearly half of all barcode sequences, while nearly 50 countries were represented by less than ten barcodes. Only five countries, Costa Rica, Canada, South Africa, Germany, and Spain, had a high sampling completeness, although collectively the barcode database covers most major taxonomic and biogeographically confined lineages. PD showed moderate saturation as more species diversity is added in a country, and community phylogenetics indicated clustering of national faunas. However, at the species level the inventory remained incomplete even in the most intensely sampled countries, and the sampling was insufficient for assessment of global species richness patterns. Discussion: The sequence-based inventory in Chrysomelidae needs to be greatly expanded to include more areas and deeper local sampling before reaching a knowledge base similar to the existing Linnaean taxonomy. However, placing the barcodes into a backbone phylogenetic tree from mitochondrial genomes, a taxonomically and biogeographically highly structured pattern of global diversity emerges into which all species can be integrated via their barcodes. [ABSTRACT FROM AUTHOR]

Based on a single specimen from Eocene Baltic amber, Donacia (Protodonacia) bienkowskii subgen. et sp. nov. is described and illustrated. The new species is studied and illustrated in detail using X-ray micro-computed tomography (μCT). It is the first described species of Donaciinae (Coleoptera: Chrysomelidae) from Baltic amber and from fossil resin in general. Ecological groups of beetles that have been associated with aquatic habitats in the Baltic amber forest communities are briefly discussed. The studied specimen represents the first known member of the ecological group 'phytophilous water beetles' in this assemblage. [ABSTRACT FROM AUTHOR]

Biological invasions pose significant threats to biodiversity, with invasive species spread often facilitated by human activities. Consequently, this research utilized ecological niche modeling (ENM) to overcome this limitation and map the potential suitability of Microtheca ochroloma Stål, 1860 and Microtheca semilaevis Stål, 1860, which have been evaluated as potential insect pests in the Americas, zones for four genera of Brassicaceae, which include globally cultivated species such as Sinapis L., Raphanus L., Eruca Mill., and Brassica L. We utilized multiple methods to forecast the ecological habitat of Microtheca Stål, 1860 species based on distribution data and various environmental indicators. Our models, exhibiting high-performance metrics (TSS ranging from 0.84 to 0.96), revealed extensive environmental suitability for these species across the Americas, including previously unreported regions. The predicted zones overlapped significantly with areas where Brassicaceae crops were grown. Contrary to some previous assertions, our findings suggest that while these Microtheca species are recognized pests on these crops, their consistent widespread damage may be overstated. Nevertheless, their invasive potential could have broad ecological impacts, including biodiversity loss. Our research emphasizes the need for focused sampling in potential distribution zones and underlines the value of integrating ENM in predicting and managing invasive species spread. [ABSTRACT FROM AUTHOR]

Simple Summary: This study aimed to elucidate the factors contributing to the limited presence of Cheilotoma musciformis in Poland, with a specific focus on soil characteristics affecting both vegetation and insect populations. It examined how soil enzyme activity influences the occurrence of Ch. musciformis in the xerothermic grasslands of Southern Poland. Sites inhabited by the beetle were typically subject to extensive grazing by farm animals or recent bush clearance, contrasting with control plots situated on unused or overgrazed xerothermic grasslands. Soils in beetle-inhabited sites exhibited significantly higher levels of enzyme activity, total organic carbon, and total nitrogen, along with lower pHKCl compared to control sites. These findings suggest the beetle's reliance on extensively grazed xerothermic grasslands. Given that grazing practices influence the behavior of preferred host plant species, effective protection planning for Ch. musciformis-inhabited grasslands should carefully consider changes in soil biochemical properties and vegetation structure. This work attempts to find the reasons for the rather limited range of occurrence of Cheilotoma musciformis in Poland, based on soil properties, which affects both the plant cover and the entomofauna. The aim of the study was to assess the influence of soil enzyme activity on the occurrence of Ch. musciformis in xerothermic grasslands in Southern Poland. The sites inhabited by the beetle were most often extensively grazed by farm animals or had recently been cleared of bushes. The control plots were in wasteland. The soils of most sites with Ch. musciformis were characterized by significantly higher activity of the tested enzymes and higher content of total organic carbon and total nitrogen, as well as lower pHKCl compared to the control sites. The higher enzymatic activity of soils in sites with the beetle than in the control sites may indicate the dependence of the occurrence of this beetle on the presence of patches of extensively grazed xerothermic grasslands. Grazing influences the behavior of preferred host plant species. Therefore, when planning active protection of xerothermic grasslands inhabited by Ch. musciformis, changes in the biochemical properties of the soil and vegetation structure should be taken into account. [ABSTRACT FROM AUTHOR]

BACKGROUND: The cabbage stem flea beetle (Psylliodes chrysocephala) is one of the most important insect pests of oilseed rape (Brassica napus) in northern Europe. The emergence of insecticide‐resistant populations and the ban on neonicotinoid seed treatments have made the management of this pest challenging and research is needed to develop alternative strategies such as RNA interference (RNAi). We investigated lethal and sublethal effects of orally delivered double‐stranded (ds)RNAs targeting P. chrysocephala orthologs of Sec23 and vacuolar adenosine triphosphatase subunit G (VatpG), which are involved in endoplasmic reticulum‐Golgi transport and organelle acidification, respectively. RESULTS: Feeding bioassays on P. chrysocephala adults showed that the highest concentration (200 ng/leaf disk) of dsSec23 caused mortalities of 76% and 56% in pre‐aestivating and post‐aestivating beetles, respectively, while the same concentration of dsVatpG led to mortality rates of ~34% in both stages. Moreover, sublethal effects, such as decreased feeding rates and attenuated locomotion were observed. Small RNA sequencing and gene expression measurements following the delivery of dsRNAs demonstrated the generation of ~21 nucleotide‐long small interfering RNAs and a systemic RNAi response in P. chrysocephala. CONCLUSION: We demonstrate that P. chrysocephala is a promising candidate for developing RNAi‐based pest management strategies. Further research is necessary to identify more effective target genes and to assess potential non‐target effects. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Development of accurate pest monitoring systems is essential for the establishment of integrated pest management strategies. Information about the pest behavior during the colonization process, as well as the sex and reproductive status of the colonizing population often are lacking and hinder their development. The cabbage stem flea beetle (CSFB, Psylliodes chrysocephala) can cause the complete destruction of oilseed rape crops (OSR, Brassica napus). In the present study, the colonization process of OSR fields by the CSFB was studied. RESULTS: More individuals were caught on the outward facing side of the traps than the side of the trap facing towards the crop at the field border and catches were higher on the trapping units at the center of the field than at its border, suggesting that more beetles were entering than leaving the crop. Catches were higher on lower traps placed near to the crop than on those positioned further from the ground and also were higher during the day than late afternoon and night. The sex‐ratio of individuals caught was skewed towards males and sexual maturity was acquired for females during the experiment. Integration of sampling data with local meteorological data showed that the catches correlated mostly with air temperature and relative humidity. CONCLUSION: This study provides new information about the dispersion of the CSFB in OSR fields during the colonization process, and highlights correlations between local meteorological factors and activity of the CSFB, and represent a new step towards implementing monitoring strategies against this pest. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, bioinspired chitinous manufacturing is leveraged to artificially reproduce iridescent gratings found in the cuticles of beetles living in concealed environments. Combining this with a melanin‐like background achieves a vibrant iridescence, similar to that produced by the multilayer reflectors in leaf beetles. In this process, the controlled production of optical structures is allowed using chitinous polymers, the same components that produce color in arthropod cuticles. This not only aids in understanding the functionality and evolutionary advantages of these structures without being limited to the existing solutions in animals—which entangle the solutions for several problems with the rubble of past functionalities—but also enables the creation of color with the second most abundant organic material on Earth, only surpassed in its ubiquity by cellulose. However, unlike cellulose‐based materials, the chitinous optical structures are produced by avoiding the use of strong organic solvents, representing a simplified approach to producing vibrant, iridescent, fully biodegradable, and ecologically integrated colors. Herein, the production of hundreds of square centimeters of iridescent chitinous surfaces, a scale suitable for imparting biodegradable color to large 3D objects, is demonstrated. [ABSTRACT FROM AUTHOR]

Maize lethal necrosis (MLN) is a viral disease caused by co-infection of Maize chlorotic mottle virus (MCMV) and a potyvirus mostly Sugarcane mosaic virus (SCMV). MLN is one of the most important maize production constraints in East Africa including Ethiopia. In this study molecular characterization was used to determine potential insect vectors that transmit MLN causing viruses in Ethiopia. Suspected insect vectors of MLN causing viruses collected from maize fields were initially identified to a genus/species level based on the morphological features. Further taxonomic determination was carried out using DNA sequencing from cytochrome oxidase primers. Pre-identified insect vectors of MLN-causing viruses were separately tested in the greenhouse for potential transmission of MCMV and SCMV. Accordingly, maize thrips, Franklinella sp. (Thysanoptera: Thripidae) and cereal leaf beetle, Oulema sp. (Coleoptera: Chrysomelidae) transmitted MCMV, whereas corn leaf aphids, Rhopalosiphum maidis Fich (Hemiptera: Aphididae) transmitted SCMV. Out of 86 maize fields surveyed, Franklinella sp. were widely distributed in 22 (25.6%) fields, mostly in Arsi and West Shewa zones of Oromia region. R. maidis was abundant in all the areas assessed, suggesting that this insect spp. is a vector for SCMV in Ethiopia. The presence of insects as vectors of MLN causing viruses on maize plants is believed to contribute to the widespread of MLN viruses from plant to plant, field to field and to new geographical areas. Thus, managing these vectors through appropriate control measures can reduce maize yield losses caused by MLN disease. [ABSTRACT FROM AUTHOR]

The present paper highlighted the occurrence of Timarcha turbida (Erichson 1841) as an artichoke pest for the first time in Tunisian crops. In fact, Timarcha was never be reported previously to develop on a Compositae (Asteraceae) host plant. Here, larva and adult stages of the pest are described and host plants affinities in genus Timarcha are discussed. [ABSTRACT FROM AUTHOR]

The cereal leaf beetle (CLB, Oulema melanopus) is one of the major cereal pests. The effect of insecticides belonging to different chemical classes, with different mechanisms of action and the active substances' concentrations on the CLB bacterial microbiome, was investigated. Targeted metagenomic analysis of the V3–V4 regions of the 16S ribosomal gene was used to determine the composition of the CLB bacterial microbiome. Each of the insecticides caused a decrease in the abundance of bacteria of the genus Pantoea, and an increase in the abundance of bacteria of the genus Stenotrophomonas, Acinetobacter, compared to untreated insects. After cypermethrin application, a decrease in the relative abundance of bacteria of the genus Pseudomonas was noted. The dominant bacterial genera in cypermethrin‐treated larvae were Lactococcus, Pantoea, while in insects exposed to chlorpyrifos or flonicamid it was Pseudomonas. Insecticide‐treated larvae were characterized, on average, by higher biodiversity and richness of bacterial genera, compared to untreated insects. The depletion of CLB‐associated bacteria resulted in a decrease in larval survival, especially after cypermethrin and chlorpyrifos treatments. The use of a metagenome‐based functional prediction approach revealed a higher predicted function of bacterial acetyl‐CoA C‐acetyltransferase in flonicamid and chlorpyrifos‐treated larvae and tRNA dimethyltransferase in cypermethrin‐treated insects than in untreated insects. [ABSTRACT FROM AUTHOR]

Simple Summary: The leaf beetle Diorhabda rybakowi Weise poses a severe threat to desert grasslands in Northwest China with its third instar larvae and adults, and even to the local ecological environment, attributed to its outbreak. Green-control attractants or repellents have become popular in recent years, but the olfactory mechanism of D. rybakowi is still unclear. Therefore, we preliminarily screened the best reference genes under different conditions and determined the bioinformatics characteristics and tissue expression profiles of D. rybakowi olfactory target genes. The recommended reference genes, RPL13a and RPS18 for tissues and RPL19 and RPS18 for sexes, were determined. Notably, the transcriptional levels of DrybOBP3, DrybOBP6, DrybOBP7, DrybOBP10, DrybOBP11, DrybCSP2, and DrybCSP5 among eleven odorant-binding proteins (OBPs) and six chemosensory proteins (CSPs) were significantly higher in the antenna. In summary, our study provides a strong basis for deepening the research of olfaction molecular mechanisms in D. rybakowi. Diorhabda rybakowi Weise is one of the dominant pests feeding on Nitraria spp., a pioneer plant used for windbreaking and sand fixation purposes, and poses a threat to local livestock and ecosystems. To clarify the key olfactory genes of D. rybakowi and provide a theoretical basis for attractant and repellent development, the optimal reference genes under two different conditions (tissue and sex) were identified, and the bioinformatics and characterization of the tissue expression profiles of two categories of soluble olfactory proteins (OBPs and CSPs) were investigated. The results showed that the best reference genes were RPL13a and RPS18 for comparison among tissues, and RPL19 and RPS18 for comparison between sexes. Strong expressions of DrybOBP3, DrybOBP6, DrybOBP7, DrybOBP10, DrybOBP11, DrybCSP2, and DrybCSP5 were found in antennae, the most important olfactory organ for D. rybakowi. These findings not only provide a basis for further in-depth research on the olfactory molecular mechanisms of host-specialized pests but also provide a theoretical basis for the future development of new chemical attractants or repellents using volatiles to control D. rybakowi. [ABSTRACT FROM AUTHOR]

Alligator weed, Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae) is an aggressive invader in waterways and pastures throughout most of the southeastern U.S.A., and California. Three insect biological control agents have provided substantial control of aquatic A. philoxeroides in the warmer parts of its range in the U.S.A. However, these insects are less effective against A. philoxeroides in riparian-terrestrial habitats. In this study, the host specificity of Disonycha argentinensis Jacoby, 1991, was investigated to determine its suitability as a biocontrol agent of A. philoxeroides in the U.S.A. No-choice and multiple-choice tests were conducted using 19 test plant species. Complete development of larvae took place only on A. philoxeroides and on a native plant, Alternanthera maritima (Mart.) A. St.-Hil. Larval survival on A. philoxeroides (0.55 ± 0.05) did not differ from A. maritima (0.35 ± 0.15), but development time (days) from first instar to adult was faster on A. philoxeroides (21.78 ± 0.67) than on A. maritima (27.64 ± 0.70). No-choice oviposition tests showed that fecundity was higher on A. philoxeroides (400.6 ± 115.2 eggs) than on A. maritima (93.5 ± 23.5 eggs), but egg viability (proportion) did not differ between A. philoxeroides (0.40 ± 0.14) and A. maritima (0.60 ± 0.19). In multiple-choice tests, D. argentinensis oviposited indiscriminately on all plant species tested. Collectively, these results indicate that the native A. maritima is within the ecological host range of D. argentinensis and further tests (e.g., field studies) are necessary to determine if predicted non-target impacts will be transitory or persistent. [ABSTRACT FROM AUTHOR]

The satellitome of the beetle Chrysolina americana Linneo, 1758 has been characterized through chromosomal analysis, genomic sequencing, and bioinformatics tools. C-banding reveals the presence of constitutive heterochromatin blocks enriched in A+T content, primarily located in pericentromeric regions. Furthermore, a comprehensive satellitome analysis unveils the extensive diversity of satellite DNA families within the genome of C. americana. Using fluorescence in situ hybridization techniques and the innovative CHRISMAPP approach, we precisely map the localization of satDNA families on assembled chromosomes, providing insights into their organization and distribution patterns. Among the 165 identified satDNA families, only three of them exhibit a remarkable amplification and accumulation, forming large blocks predominantly in pericentromeric regions. In contrast, the remaining, less abundant satDNA families are dispersed throughout euchromatic regions, challenging the traditional association of satDNA with heterochromatin. Overall, our findings underscore the complexity of repetitive DNA elements in the genome of C. americana and emphasize the need for further exploration to elucidate their functional significance and evolutionary implications. [ABSTRACT FROM AUTHOR]

Mate-guarding behaviour is thought to beneficially increase paternal share by lowering sperm competition. It is likely to be a plastic response that changes with the density of rivals in the surroundings. A recent study showed that the Parthenium beetle, Zygogramma bicolorata (Coleoptera: Chrysomelidae), exhibits mate-guarding behaviour through prolonged mating duration. The goal of the present study was to evaluate the flexibility of this behaviour when rivals were present. A pair of Z. bicolorata were placed in the physical presence and chemical cues of rivals of both sexes at different densities, and their precopulatory behaviours (time to commencement of mating, latent period, mate-guarding duration and reproductive output) were noted. We hypothesized that population densities of rivals of both sexes would influence the mate-guarding behaviour and reproductive outputs. Our results revealed that population density has significant effects on precopulatory parameters and reproductive outputs. Mate-guarding duration decreased in the physical presence of rivals, while it increased in the presence of chemical cues. In the physical presence of rivals, mate guarding probably decreased due to the repeated harassment of the focal pair, especially the male partner, by the rivals in the experimental arena. However, reproductive outputs (fecundity and percentage egg viability) were increased in both the physical presence and chemical cues of males and females. Hence our results clearly support the previous observation of mate-guarding behaviour through prolonged mating duration in the Parthenium beetle, and show its plasticity. • Plasticity of mate-guarding behaviour in response to adult density was studied. • Results revealed a significant effect of density on mate-guarding behaviour. • Physical presence of rivals significantly decreases mate guarding in focal pair. • Chemical cues of rival males or females increase mate guarding in focal pair. • Reproductive output increases with both physical and chemical presence of rivals. [ABSTRACT FROM AUTHOR]

Allium mongolicum Regel leaf beetle, Galeruca daurica (Coleoptera: Chrysomelidae) is rampantly harmful in Inner Mongolia grassland. However, the current management strategies for this pest still heavily rely on chemical control using traditional insecticides or those with novel action. In the study, we conducted an indoor bioassay to evaluate the sublethal effects of chlorantraniliprole on the biological characteristics. Additionally, we assessed the activity of detoxification enzymes, specifically the primary enzymes carboxylesterase (CarE) and cytochrome P450, and insect's secondary metabolic enzymes, namely glutathione S‐transferase (GST) and uridine diphosphate glycosyltransferase (UGT), as well as its gene expression profile. The developmental period of the 3rd instar larvae of G. daurica was significantly prolonged after treatment with chlorantraniliprole, which negatively affected the hatching, pupation and diapause rates as well as their body weight. The larvae showed different dynamics of the enzyme activities within 24 h of chlorantraniliprole treatment. Different sublethal concentrations of chlorantraniliprole showed an inducing effect on the activities, while no significant difference in activity was observed for P450. Expression profiling of detoxifying enzyme genes screened by transcriptome data has revealed that 6 CarE, 2 GST, 7 UGT and 31 P450 genes were up‐regulated. In conclusion, chlorantraniliprole's sublethal effect on 3rd instar G. daurica larvae resulted in a deceleration of their growth and developmental processes and significantly increased the activity levels of CarE, GST and UGT. The detoxifying proteins encoded by up‐regulation genes may involve in the detoxification metabolism of chlorantraniliprole. Our results provide a basis for understanding the molecular mechanisms of chlorantraniliprole action and detoxification in this key grassland insect pest. [ABSTRACT FROM AUTHOR]

Larvae of the southern corn rootworm (SCR) Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae) are primary pests of peanut in the Virginia-Carolina region of the United States, and are relatively sporadic pests in southern states such as Georgia, Alabama, and Florida. Peanuts have strict quality standards which, when they are not met, can diminish crop value by more than 65%. Management of direct pests like SCR is therefore crucial to maintaining the economic viability of the crop. The soil-dwelling nature of SCR larvae complicates management due to difficulties associated with monitoring and predicting infestations. Nonchemical management options are limited in this system; preventative insecticide applications are the most reliable management strategy for at-risk fields. Chlorpyrifos was the standard product for larval SCR management in peanut until its registration was revoked in 2022, leaving no effective chemical management option for larvae. We tested a novel insecticide, isocycloseram, for its ability to reduce pod scarring, pod penetration, and non-SCR pod damage in field studies conducted in Suffolk, Virginia in 2020–2022. Overall injury was low in 2020 and 2022, and in 2022 there was not a significant effect of treatment. In 2021, 2 simulated chemigation applications of isocycloseram in July significantly reduced pod scarring and overall pod injury relative to chlorpyrifos and the untreated control. Our results suggest that isocycloseram may become an effective option for managing SCR in peanut, although more work is needed to understand the mechanisms by which it is effective as a soil-applied insecticide. [ABSTRACT FROM AUTHOR]

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The article presents an analysis of the results of using a large number of pitfall trap lines to record the species composition of the two largest groups of phytophagous beetles (Coleoptera: Chrysomelidae and Curculionoidea) on the example of the territory of one region of the European part of Russia (the Republic of Mordovia). A series of collections were conducted between April and October 2022-2023, encompassing a diverse array of habitats (forest, steppe, near-water, wasteland) across various parts of the region. A total of 126 species from four families (approximately 18% of the fauna of the Republic of Mordovia) were recorded. These included 84 species of Curculionidae (22.9% of species), 42 species of Chrysomelidae (22.9%), 3 species of Brentidae, and 1 species of Anthribidae. Fourteen species are presented for the first time in the regional fauna. The collections are dominated by species whose adults are actively moving on soil or litter, particularly those belonging to the Alticini (Chrysomelidae) (33 species; 38.4% of the fauna composition) and the subfamily Entiminae (Curculionidae) (32 species; 45.1%). The collections represent a wide range of landscape-biotopic groups (meadow, ruderal, forest, nearwater, and steppe species). Extensive materials obtained in pine forests and their pyrogenic successions in the Mordovia State Nature Reserve were also analyzed. The maximum species richness (30 species) was observed on fresh pyrogenic wastelands (1-2 years after fires). This is due to the association of many species of leafhoppers and weevils with habitats with sparse ruderal vegetation and coenophobic plants. A minimum of 10 species was observed on plots of old burned areas (13 years) where the primary vegetation is degraded and a full-fledged pine forest complex has not yet formed. The maximum abundance of two ecologically plastic species (Strophosoma capitatum and Hylobius abietis) associated with young undergrowth of pine and deciduous trees was recorded in this area. [ABSTRACT FROM AUTHOR]

Abstract Canola (Brassica napus L. and B. rapa L. [Brassicales: Brassicaceae]) is a major oilseed crop grown globally as a source of vegetable oil, animal feed and biofuel feedstock. The global demand for canola oil as a biofuel feedstock has increased due to recent regulations in the European Union, United States, and Canada. In North America, canola production is centered on the northern Great Plains where it is challenged by two highly destructive flea beetle species, the crucifer (Phyllotreta cruciferae Goeze, 1777) and the striped (Phyllotreta striolata Fabricius, 1803) flea beetles. In the spring, adult P. cruciferae and P. striolata begin feeding on canola seedlings, creating a ‘shot hole’ appearance, which can reduce the plant's photosynthetic capacity leading to uneven plant emergence and growth, reduced plant stand density, and reduced seed yield. Losses resulting from flea beetles are estimated in the tens of millions of dollars annually. At present, the principle means for flea beetle control are insecticides applied as systemic seed treatments and/or subsequent foliar sprays. The continued use of these products is being questioned due to environmental concerns and acquisition of resistance. As such, significant research effort is being directed toward the development of an integrated pest management system for these abundant and hard to manage pests of canola. Here, we review the ecology, pest status, and management of flea beetles in North America and discuss future research needed to promote flea beetle management and sustainable canola production.