Investigation of Fungal Community Structure in the Gut of the Stag Beetle Dorcus hopei (Coleoptera; Lucanidae): Comparisons Among Developmental Stages.

Stag beetles, recognized as common saproxylic insects, are valued for their vibrant coloration and distinctive morphology. These beetles play a crucial ecological role in decomposition and nutrient cycling, serving as a vital functional component in ecosystem functioning. Although previous studies have confirmed that stag beetles are predominantly fungivores, the fluctuations in their intestinal fungal communities at different developmental stages remain poorly understood. In the current study, high-throughput sequencing was employed to investigate the dynamic changes within intestinal fungal communities at various developmental stages in the stag beetle Dorcus hopei. Results showed that microbial diversity was higher during the larval stage than during the pupal and adult stages. Furthermore, significant differences were identified in the composition of the intestinal fungal communities across the larval, pupal, and adult stages, suggesting that developmental transitions may be crucial factors contributing to variations in fungal community composition and diversity. Dominant genera included Candida, Scheffersomyces, Phaeoacremonium, and Trichosporon. Functional predictions indicated a greater diversity and relative abundance of endosymbiotic fungi in the larval gut, suggesting a potential dependency of larvae on beneficial gut fungi for nutrient acquisition. Additionally, the application of abundance-based ß-null deviation and niche width analyses revealed that the adult gut exerted a stronger selection pressure on its fungal community, favoring certain taxa. This selection process culminates in a more robust co-occurrence network of fungal communities within the adult gut, thereby enhancing their adaptability to environmental fluctuations. This study advances our understanding of the intestinal fungal community structure in stag beetles, providing a crucial theoretical foundation for the development of saproxylic beetle resources, biomass energy utilization, plastic degradation strategies, and beetle conservation efforts.

Functional analysis of nuclear receptor genes in molting and metamorphosis of the cigarette beetle, Lasioderma serricorne.

Nuclear receptors (NRs) are ligand-regulated transcription factors that are important for the normal growth and development of insects. However, systematic function analysis of NRs in the molting process of Lasioderma serricorne has not been reported. In this study, we identified and characterized 16 NR genes from L. serricorne. Spatiotemporal expression analysis revealed that six NRs were mainly expressed in 3-d-old 4th-instar larvae; five NRs were primarily expressed in 5-d-old adults and four NRs were predominately expressed in prepupae. All the NRs were highly expressed in epidermis, fat body and foregut. RNA interference (RNAi) experiments revealed that knockdown of 15 NRs disrupted the larva-pupa-adult transitions and caused 64.44-100 % mortality. Hematoxylin-eosin staining showed that depletion of 12 NRs prevented the formation of new cuticle and disrupted apolysis of old cuticle. Silencing of LsHR96, LsSVP and LsE78 led to newly formed cuticle that was thinner than the controls. The 20E titer and chitin content significantly decreased by 17.67-95.12 % after 15 NR dsRNA injection and the gene expression levels of 20E synthesis genes and chitin metabolism genes were significantly reduced. These results demonstrated that 15 NR genes are essential for normal molting and metamorphosis of L. serricorne by regulating 20E synthesis and chitin metabolism.

Micro-CT data of complete metamorphosis process in Harmonia axyridis.

Insect metamorphosis involves significant changes in insect internal structure and is thus a critical focus of entomological research. Investigating the morphological transformation of internal structures is vital to understanding the origins of adult insect organs. Beetles are among the most species-rich groups in insects, but the development and transformation of their internal organs have yet to be systematically documented. In this study, we have acquired a comprehensive dataset that includes 27 detailed whole-body tomographic image sets of Harmonia axyridis, spanning from the prepupal to the pupal stages. Utilizing this data, we have created intricate 3D models of key internal organs, encompassing the brain, ventral nerve cord, digestive and excretion systems, as well as the body wall muscles. These data documented the transformation process of these critical organs and correlations between the origin of adult and larval organs and can be used to enhance the understanding of holometabolous adult organ genesis and offers a valuable reference model for investigating complete metamorphosis in insects.

Novel Environmentally Friendly RNAi Biopesticides: Targeting V-ATPase in Holotrichia parallela Larvae Using Layered Double Hydroxide Nanocomplexes.

RNA interference (RNAi)-based biopesticides offer an attractive avenue for pest control. Previous studies revealed high RNAi sensitivity in Holotrichia parallela larvae, showcasing its potential for grub control. In this study, we aimed to develop an environmentally friendly RNAi method for H. parallela larvae. The double-stranded RNA (dsRNA) of the V-ATPase-a gene (HpVAA) was loaded onto layered double hydroxide (LDH). The dsRNA/LDH nanocomplex exhibited increased environmental stability, and we investigated the absorption rate and permeability of dsRNA-nanoparticle complexes and explored the RNAi controlling effect. Silencing the HpVAA gene was found to darken the epidermis of H. parallela larvae, with growth cessation or death or mortality, disrupting the epidermis and midgut structure. Quantitative reverse transcription-polymerase chain reaction and confocal microscopy confirmed the effective absorption of the dsRNA/LDH nanocomplex by peanut plants, with distribution in roots, stems, and leaves. Nanomaterial-mediated RNAi silenced the target genes, leading to the death of pests. Therefore, these findings indicate the successful application of the nanomaterial-mediated RNAi system for underground pests, thus establishing a theoretical foundation for developing a green, safe, and efficient pest control strategy.

The oviposition preference and offspring performance of Aethina tumida (Coleoptera: Nitidulidae).

Given the rapid spread and potential harm caused by the small hive beetle, Aethina tumida (Coleoptera: Nitidulidae) in China, it has become imperative to comprehend the developmental biology of this invasive species. Currently, there is limited knowledge regarding the impact of A. tumida female oviposition site preference on larval growth and development. To examine this, we investigated the ovipositional preference of adult female A. tumida on bee pupae, beebread, banana, and honey through a free choice test. Furthermore, we assessed the impact of these food resources on offspring performance, which included larval development time, survival, wandering larvae weight, emerged adult body mass, reproduction, and juvenile hormone titer. Our results showed that A. tumida females exhibited a strong preference for ovipositing on bee pupae compared to other diets, while showing reluctance toward honey. Moreover, A. tumida larvae that were fed on bee pupae displayed accelerated growth compared to those fed on other diets. Furthermore, A. tumida fed on bee pupae exhibited higher weights for wandering larvae, and emerged adult, increased pupation rates, enhanced fecundity and fertility, as well as a larger number of unilateral ovarioles during the larval stage when compared to those fed on other diets. Overall, the results indicate that the oviposition preferences of A. tumida females are adaptive, as their choices can enhance the fitness of their offspring. This finding aligns broadly with the hypothesis of oviposition preference and larval performance. This study can provide a foundation for the development of attractants aimed at promoting the oviposition of the A. tumida adults.

Impact of Aphis pomi-tending Formica rufa (Hymenoptera: Formicidae) on biological parameters of Hippodamia variegata (Coleoptera: Coccinellidae).

One of the key reasons for the poor performance of natural enemies of honeydew-producing insect pests is mutualism between ants and some aphid species. The findings demonstrated that red wood ant, Formica rufa Linnaeus (Hymenoptera: Formicidae) had a deleterious impact on different biological parameters of the lady beetle, Hippodamia variegata Goeze (Coleoptera: Coccinellidae). H. variegata laid far fewer eggs in ant-tended aphid colonies, laying nearly 2.5 times more eggs in ant absence. Ants antennated and bit the lady beetle eggs, resulting in significantly low egg hatching of 66 per cent over 85 per cent in ant absent treatments. The presence of ants significantly reduced the development of all larval instars. The highest reduction was found in the fourth larval instar (31.33% reduction), and the lowest in the first larval instar (20% reduction). Later larval instars were more aggressively attacked by ants than earlier instars. The first and second larval instars stopped their feeding and movement in response to ant aggression. The third and fourth larval instars modified their mobility, resulting in increased ant aggression towards them. Adult lady beetles were shown to be more vulnerable to ant attacks than larvae. However, H. variegata adults demonstrated counterattacks in the form of diverse defensive reaction behaviours in response to F. rufa aggression.

The Neurotranscriptome of Monochamus alternatus.

The Japanese pine sawyer Monochamus alternatus serves as the primary vector for pine wilt disease, a devastating pine disease that poses a significant threat to the sustainable development of forestry in the Eurasian region. Currently, trap devices based on informational compounds have played a crucial role in monitoring and controlling the M. alternatus population. However, the specific proteins within M. alternatus involved in recognizing the aforementioned informational compounds remain largely unclear. To elucidate the spatiotemporal distribution of M. alternatus chemosensory-related genes, this study conducted neural transcriptome analyses to investigate gene expression patterns in different body parts during the feeding and mating stages of both male and female beetles. The results revealed that 15 genes in the gustatory receptor (GR) gene family exhibited high expression in the mouthparts, most genes in the odorant binding protein (OBP) gene family exhibited high expression across all body parts, 22 genes in the odorant receptor (OR) gene family exhibited high expression in the antennae, a significant number of genes in the chemosensory protein (CSP) and sensory neuron membrane protein (SNMP) gene families exhibited high expression in both the mouthparts and antennae, and 30 genes in the ionotropic receptors (IR) gene family were expressed in the antennae. Through co-expression analyses, it was observed that 34 genes in the IR gene family were co-expressed across the four developmental stages. The Antenna IR subfamily and IR8a/Ir25a subfamily exhibited relatively high expression levels in the antennae, while the Kainate subfamily, NMDA subfamily, and Divergent subfamily exhibited predominantly high expression in the facial region. MalIR33 is expressed only during the feeding stage of M. alternatus, the MalIR37 gene exhibits specific expression in male beetles, the MalIR34 gene exhibits specific expression during the feeding stage in male beetles, the MalIR8 and MalIR39 genes exhibit specific expression during the feeding stage in female beetles, and MalIR8 is expressed only during two developmental stages in male beetles and during the mating stage in female beetles. The IR gene family exhibits gene-specific expression in different spatiotemporal contexts, laying the foundation for the subsequent selection of functional genes and facilitating the full utilization of host plant volatiles and insect sex pheromones, thereby enabling the development of more efficient attractants.

Temperature-induced effects on development, reproduction, and predation of Harmonia axyridis fed on first instar larvae Spodoptera litura.

Since metabolism, survival, and reproduction in hexapods are closely related to temperatures; changes in the mean and variance of temperature are major aspects of global climate change. In the typical context of biological control, understanding how predator-prey systems are impacted under thermal conditions can make pest control more effective and resilient. With this view, this study investigated temperature-mediated development and predation parameters of the predator Harmonia axyridis against the potential prey Spodoptera litura. The age-stage, two-sex life table of the predator was constructed at four temperatures (i.e. 15, 20, 25, and 30°C) by feeding on the first instar larvae of S. litura. Our results showed that the mean generation time (T) decreased but the intrinsic rate of increase (r) and the finite rate of increase (λ) increased with increased temperature. The mean duration of the total preadult stage decreased with higher temperatures. The T and r were 70.47 d and 0.0769 d-1 at 15°C; 58.41 d and 0.0958 d-1 at 20°C; 38.71 d and 0.1526 d-1 at 25°C; and 29.59 d and 0.1822 d-1 at 30°C, respectively. The highest net reproductive rate (R0) and fecundity were obtained at 25°C. The highest λ (1.1998 d-1) and lowest T (29.59 d) were obtained at 30°C, whereas the maximum net predation rate (C0) was at 25°C. Total population and predation rates projections were the highest at 30°C. Based on these findings, we anticipate that biological control strategies for this predator release against S. litura should be attuned to warming scenarios to achieve better biocontrol functions.

Functional analysis of adipokinetic hormone signaling in reproductive diapause of Coccinella septempunctata.

BACKGROUND: The ladybeetle, Coccinella septempunctata, an important predator, is widely used to control aphids, whiteflies, mites, thrips, and lepidopteran pests. Diapause control technology is key to extending C. septempunctata shelf-life and commercialization. Lipid accumulation is a major feature of reproductive diapause, but the function of AKH signaling as a regulator of lipid mobilization in reproductive diapause remains unclear. This study aimed to identify and characterize AKH and AKHR genes, and clarify their functions in reproductive diapause. RESULTS: The relative expression levels of CsAKH and CsAKHR were the highest in the head and fat body, respectively, and were significantly decreased under diapause conditions, both in developmental stages and tissues (head, midgut, fat body, and ovary). Furthermore, CsAKH and CsAKHR expression was increased significantly after juvenile hormone (JH) injection, but CsMet silencing significantly inhibited CsAKH and CsAKHR expression, whereas CsMet knockdown blocked the induction effect of JH. CsAKH and CsAKHR knockdown significantly reduced water content, increased lipid storage, and promoted the expression of genes related to lipid synthesis, but significantly blocked ovarian development, and induced forkhead box O (FOXO) gene expression in C. septempunctata under reproduction conditions. By contrast, injection of AKH peptide significantly inhibited FOXO expression, reduced lipid storage, and increased water content in C. septempunctata under diapause conditions. CONCLUSION: These results indicate that CsAKH and CsAKHR are involved in the regulation of lipid accumulation and ovarian development during diapause in C. septempunctata, and provide a promising target for manipulating C. septempunctata diapause. © 2024 Society of Chemical Industry.

Morphometric analysis for determination of larval instars in Dermestes frischii Kugelann and Dermestes undulatus Brahm (Coleoptera: Dermestidae).

Dermestes frischii Kugelann, 1792 and Dermestes undulatus Brahm, 1790 are the most abundant species worldwide at outdoor or indoor crime scenes during the dry and skeletal stages of decomposition. The attribution of larval age in these beetles is problematic due to the variable number of instars, which is influenced by environmental factors. In this study, a morphometric approach was used to look for potential morphological features as evidence of larval stages. Breeding and monitoring were performed for both species in an incubator with a preset temperature of 28°C ± 0.5 without a photoperiod. Morphometric measurements were made on 10 larvae per instar for each species using length, width, and thickness parameters. Linear discriminant analysis was then used to generate decision boundaries that clearly separated larval stages. The cross-validation procedure demonstrated that the morphometric approach successfully discriminated adjacent larval stages in both species with high values of sensitivity and specificity. This less-invasive approach could improve the ability to estimate minPMI in forensic studies of Dermestidae beetles. Future studies may extend this approach to other species and establish good practices for collecting and storing specimens for morphometric analysis.

Larvae of Cryptolaemus montrouzieri (Coleoptera: Coccinellidae) Prioritize Secretion of Protective Wax Over Daily Consumption and Growth.

In holometabolous insects, the immature or larval stage is characterized by a high rate of food consumption. The nutrients obtained from which are directed towards the maintenance of metabolism, growth, pupation, and metamorphosis. However, when resources are scarce, the lack thereof can affect the growth rate and compromise the metamorphosis and formation of adults. Do increased energy expenditures yield outcomes similar to those resulting from restricted food intake during the larval stage? We hypothesized that removing the wax layer from the larvae of the ladybird Cryptolaemus montrouzieri Mulsant, 1850 would result in increased energy expenditure, which can compromise both larval growth and adult size. We compared the development time, feeding rate, and adult size of larvae with an intact wax layer, and those with constantly removed wax layers. We found that the production of the wax layer was continuous. Unlike the waxed larvae, the larvae of C. montrouzieri extended their development time in response to energy depletion through wax removal. The total number of mealybugs consumed by waxless larvae was higher than the total number consumed by waxed larvae; however, the daily consumption of waxless larvae was lower than that of waxed larvae. Furthermore, the adults of waxless larvae were smaller than those whose larvae had intact wax layers. This suggests that the cost associated with wax layer secretion is a pivotal factor in larval growth. Removing this layer does not get compensated by increased larval feeding or extended development time.

Canola bee pollen is an effective artificial diet additive for improving larval development of predatory coccinellids: a lesson from Harmonia axyridis.

BACKGROUND: Pollen is a common plant-derived food source for predatory ladybird beetles under field conditions, yet the potential for pollen to improve the quality of artificial diets remains largely unexplored. In this study, we developed three pollen diets by incorporating varying proportions of canola bee pollen (7.5%, 15.0% and 22.5% with 2.5%, 5.0%, and 7.5% of water, respectively) into a conventional diet. The feeding efficiency of Harmonia axyridis, an omnivorous predator, was evaluated and compared on three pollen diets, a conventional nonpollen diet and pea aphids. RESULTS: The larvae fed a medium or high pollen diet exhibited significantly higher survival in the 4th instar, pupa and adult stages than those fed a nonpollen diet. These larvae also developed into significantly heavier adults, and their survival rates in adulthood were comparable to those fed pea aphids. Specifically, we revealed the underlying mechanisms through which a high pollen diet enhances pupal development. Consumption of high pollen diet versus nonpollen diet resulted not only in a significant decrease in pupal glycogen content, but also an increase in adult lipid content. Both diet treatments induced similar changes in carbohydrate and glycogen content compared to the aphid diet while exhibiting different alterations in pupal protein content and adult lipid content. Furthermore, the transcriptome analysis revealed that the nutrient metabolism, immune response, and cuticle development pathways were predominantly enriched among the differentially expressed genes (DEGs). CONCLUSION: Canola bee pollen offers diverse advantages in terms of rearing H. axyridis larvae with an artificial diet, which will advance the development of effective diets for predaceous coccinellids. © 2024 Society of Chemical Industry.

Evolution of horn length and lifting strength in the Japanese rhinoceros beetle Trypoxylus dichotomus.

What limits the size of nature's most extreme structures? For weapons like beetle horns, one possibility is a tradeoff associated with mechanical levers: as the output arm of the lever system-the beetle horn-gets longer, it also gets weaker. This "paradox of the weakening combatant" could offset reproductive advantages of additional increases in weapon size. However, in contemporary populations of most heavily weaponed species, males with the longest weapons also tend to be the strongest, presumably because selection drove the evolution of compensatory changes to these lever systems that ameliorated the force reductions of increased weapon size. Therefore, we test for biomechanical limits by reconstructing the stages of weapon evolution, exploring whether initial increases in weapon length first led to reductions in weapon force generation that were later ameliorated through the evolution of mechanisms of mechanical compensation. We describe phylogeographic relationships among populations of a rhinoceros beetle and show that the "pitchfork" shaped head horn likely increased in length independently in the northern and southern radiations of beetles. Both increases in horn length were associated with dramatic reductions to horn lifting strength-compelling evidence for the paradox of the weakening combatant-and these initial reductions to horn strength were later ameliorated in some populations through reductions to horn length or through increases in head height (the input arm for the horn lever system). Our results reveal an exciting geographic mosaic of weapon size, weapon force, and mechanical compensation, shedding light on larger questions pertaining to the evolution of extreme structures.

Egg development and viability in three species of Cyclocephala (Coleoptera: Scarabaeidae: Dynastinae).

Different species of Cyclocephala scarab beetles (Scarabaeidae, Dynastinae) perform key functional roles in both natural and agricultural systems, such as the cycling of organic matter and pollination, while also being known as destructive pests both as immatures and adults. Therefore, the identification of biological parameters is crucial for defining strategies for their conservation and efficient pest management. In a forest fragment within the Brazilian Atlantic Forest biodiversity hotspot, we field-captured adult individuals of Cyclocephala cearae, C. celata, and C. paraguayensis then reared and bred them under controlled temperature and humidity conditions. On a daily basis, we individually weighted eggs of all three species, from oviposition until hatching, and monitored egg development parameters (i.e., incubation duration, viability, and egg weight increase). Our findings provide novel empirical evidence showing (i) a positive correlation between egg weight and incubation duration, (ii) idiosyncratic characteristics on egg development, and (iii) a negative (involuntary) effect of manipulation on egg development and viability. Thus, the successful breeding and rearing of Cyclocephala spp. is correlated with egg integrity and the targeted species. Our analyses present a quantitative understanding of the egg phase and can assist in refining strategies for ovicidal activity and pest management of Cyclocephala spp. in agriculture systems. Moreover, they can provide a basis for new studies related to captivity breeding, pollinator management, and developmental biology for biodiversity conservation.

Coleoborers in Bambusa sp. in the Southern Amazon / Coleobrocas em Bambusa sp. na Amazonia Meridional

Bamboo (Bambusa sp.) is a grass species with high potential for exploitation, however, this raw material is easily attacked by xylophagous agents such as Coleoptera. The objective of this study is thus to analyse the presence of wood-boring beetles associated with Bambusa sp. in Alta Floresta, Mato Grosso, Brazil. The study was carried out in a bamboo plantation, from August 2016 to July 2017. Two models of ethanolic traps were used, PET Santa Maria and ESALQ-84. Three families of wood-boring beetles were observed in this study: Bostrichidae, Cerambycidae and Curculionidae. 2,144 individuals were identified, belonging to 19 species, in four subfamilies and 11 tribes, and the species Xyleborus affinis was the most frequently collected. Thus, this study constitutes an important contribution to the knowledge of coleoborers associated with bamboo plantations, with the registration of the occurrence of species, as well as contributing to the knowledge of the entomofauna associated with species cultivated in the Southern Amazon.

O bambu (Bambusa sp.) é uma espécie de gramínea com alto potencial de exploração de fibras, no entanto, essa matéria-prima é facilmente atacada por agentes xilófagos, como os coleópteros. O objetivo deste estudo foi analisar a presença de besouros associados a Bambusa sp. em Alta Floresta, Mato Grosso, Brasil. O estudo foi realizado em um plantio de bambu, no período de agosto de 2016 a julho de 2017. Foram utilizados dois modelos de armadilhas etanólicas, o PET Santa Maria e ESALQ-84. Três famílias de coleobrocas foram observadas neste estudo: Bostrichidae, Cerambycidae e Curculionidae. Foram identificados 2,144 indivíduos, pertencentes a 19 espécies, em quatro subfamílias e 11 tribos, e Xyleborus affinis foi a espécie com maior número de indivíduos coletados. Assim, este estudo constitui-se em uma importante contribuição para o conhecimento de coleobrocas associadas a plantios de bamboo, com o registro de ocorrência de espécies, bem como contribui para o conhecimento da entomofauna associada a espécies cultivadas na Amazônia Meridional.

Chewing insects, pollinators, and predators on Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae) plants fertilized with dehydrated sewage sludge / Insetos mastigadores, polinizadores e predadores em plantas de Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae) fertilizada com lodo de esgoto desidratado

Fertilization with dehydrated sewage sludge can speed up the recovery process of degraded areas due to nutrients concentration, favoring the development of pioneer plants such as Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae) and the emergence of insects. This study aimed the evaluation of chewing, pollinating insects, predators, their ecological indices and relationships on A. auriculiformis plants fertilized with dehydrated sewage sludge. The experimental design was completely randomized with two treatments (with and without dehydrated sewage sludge) and 24 repetitions. The prevalence of chewing insects Parasyphraea sp. (Coleoptera: Chrysomelidae), Nasutitermes sp. (Blattodea: Termitidae), and Tropidacris collaris (Stoll, 1813) (Orthoptera: Romaleidae), defoliation, and ecological indices of abundance of Coleoptera and Orthoptera were observed on fertilized A. auriculiformis. Acacia auriculiformis plants, with a superior number of branches/tree, revealed greater abundance of Coleoptera and Orthoptera, species richness of pollinating insects, defoliation, numbers of Parasyphraea sp. and T. collaris. The ones with larger leaves/branches displayed greater abundance of species richness of Coleoptera and Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae). Therefore, the use of A. auriculiformis plants, fertilized with dehydrated sewage sludge, is promising in the recovery of degraded areas due to the ecological indices increase of chewing and pollinators insects and spiders in the analyzed area.

A fertilização com lodo de esgoto desidratado pode acelerar o processo de recuperação de áreas degradadas devido à concentração de nutrientes, favorecendo o desenvolvimento de plantas pioneiras tais como Acacia auriculiformis A. Cunn. ex Beth (Fabales: Fabaceae) e de seus insetos. O objetivo deste trabalho foi avaliar os insetos mastigadores, polinizadores e predadores e seus índices e relações ecológicas em plantas de A. auriculiformis fertilizadas com lodo de esgoto desidratado, em área degradada, durante 24 meses. O delineamento foi inteiramente casualizados com dois tratamentos (com e sem adubação com lodo de esgoto desidratado) e 24 repetições (uma repetição = uma planta). O maior número de insetos mastigadores Parasyphraea sp. (Coleoptera: Chrysomelidae), Nasutitermes sp. (Blattodea: Termitidae) e Tropidacris collaris (Stoll, 1813) (Orthoptera: Romaleidae), de desfolha, e do índice ecológico abundância de Coleoptera e de Orthoptera foram maiores em plantas de A. auriculiformis fertilizadas do que nas não fertilizadas com lodo de esgoto desidratado. Plantas de A. auriculiformis, com maior quantidade de galhos/árvore, apresentaram maiores abundâncias de Coleoptera e Orthoptera, riqueza de espécies de insetos polinizadores, desfolha e números de Parasyphraea sp. e T. collaris, e as com maior folhas/galho os de riqueza de espécies de Coleoptera e Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae). Por tanto, a utilização de A. auriculiformis, adubada com lodo de esgoto desidratado, é promissora na recuperação de áreas degradadas devido ao aumento dos índices ecológicos de insetos mastigadores, polinizadores e aranhas na área.

Depredación, reproducción y desarrollo de la catarina Hippodamia convergens (Coleoptera: Coccinellidae) / Predation, reproduction, and development of the lady beetle Hippodamia convergens (Coleoptera: Coccinellidae)

Introducción: Mantener poblaciones de insectos depredadores en el agroecosistema ofreciéndoles presas y recursos alimenticios provenientes de las plantas es importante para mejorar el control biológico y contribuir con la conservación. Objetivo: Determinar si el consumo de presas y recursos alimenticios florales potencia los atributos biológicos del depredado Hippodamia convergens. Métodos: Las larvas de Hippodamia convergens fueron alimentadas con dos especies de áfidos, mientras que los adultos fueron alimentados con áfidos, espigas de maíz y dos especies de plantas no cultivadas. La presencia de azúcar en el intestino del depredador se comprobó mediante la prueba de antronas frías, y la presencia de polen mediante el método de acetólisis. Los experimentos demográficos se realizaron durante los primeros 40 días después de la emergencia de la hembra bajo condiciones controladas (25 °C ± 0.5; 75 % ± 1.75 HR; L12:D12). Resultados: H. convergens no consumió fructosa de Sorghum halepense, Parthenium hysterophorus o Zea mays, sino únicamente polen. En condiciones controladas (25 °C ± 0.5, 75 % ± 1.75 HR), el tiempo de desarrollo (huevo-adulto) del depredador fue más corto (21.36 días) cuando consumió Rhopalosiphum maidis en lugar de Uroleucon nigrotibium (24.6 días), mientras que la supervivencia (L1- adulto) y la proporción sexual no cambió. La fecundidad promedio fue mayor (55.5 huevos / 40 días) al consumir U. nigrotibium con polen de P. hysterophorus, que solo U. nigrotibium (22.5 huevos / 40 días), o R. maidis con polen de Zea mays (11 huevos / 40 días). La tasa intrínseca de crecimiento natural fue mayor al consumir U. nigrotibium con polen de P. hysterophorus (0.055), que U. nigrotibium (0.034) o R. maidis con polen de Z. mays (0.019). La tasa de depredación (L1-L5) fue mayor al consumir R. maidis (0.65) que U. nigrotibium (0.51). Conclusiones: Las especies de áfidos y su combinación con polen de plantas no cultivadas afectan de manera diferente el tiempo de desarrollo, reproducción y tasa de depredación de H. convergens.

Introduction: Keeping populations of predatory insects in the agroecosystem by offering them prey, as well as food resources from plants, is important for enhancing conservation biological control. Objective: To determine if the consumption of prey and floral food resources enhances the biological attributes of the predator Hippodamia convergens. Methods: We fed the beetle larvae two species of aphids; and the adults were fed aphids, maize tassels, and two non-cultivated plant species. We checked gut sugar in the predator by the cold anthrone test and pollen presence by the acetolysis method. Demographic experiments were done in the first 40 days after female emergence, under controlled conditions (25 °C ± 0.5; 75 % ± 1.75 Relative Humidity; Light 12 h: Darkness 12 h). Results: H. convergens did not consume fructose, but only pollen from Sorghum halepense, Parthenium hysterophorus or Zea mays. Developmental time (egg-adult) of the predator was shorter (21.4 days) when it consumed Rhopalosiphum maidis than Uroleucon nigrotibium (24.6 days); survival (L1-adult) and sex ratio did not change. Average fecundity was higher (55.5 eggs / 40 days) when consuming U. nigrotibium with pollen from P. hysterophorus, than U. nigrotibium (22.5 eggs / 40 days) or R. maidis with pollen from Zea mays (11 eggs / 40 days). The intrinsic rate of natural growth was higher when consuming U. nigrotibium with pollen from P. hysterophorus (0.055), than U. nigrotibium (0.034) or R. maidis with pollen from Z. mays (0.019). Predation rate (L1-L5) was higher when consuming R. maidis (0.65) than U. nigrotibium (0.51). Conclusions: Aphid prey species and its combination with pollen from maize and non-cultivated plants affected development time, reproduction, and predation rate of H. convergens.

Larval morphology of the Neotropical diving beetle genus Hemibidessus Zimmermann, 1921 (Coleoptera: Dytiscidae: Bidessini).

We describe for the first time the larva of the diving-beetle genus Hemibidessus Zimmermann, 1921, based on instars II and III of H. conicus (Zimmermann, 1921). We include detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi in order to discover useful characters for distinguishing Hemibidessus larvae from those of other known Bidessini. Hemibidessus larvae characteristically have elongate legs armed with natatory setae and elongate urogomphi that bear numerous secondary setae, features commonly associated with an increased swimming ability. These characters are shared with Brachyvatus Zimmermann, 1921, suggesting a close phylogenetic relationship between these two genera. The primary seta UR8 is inserted apically on urogomphomere 2 in Hemibidessus larvae, a feature so far only shared with the mature larva of Yola Gozis, 1886. Other characters that combined with those previously mentioned are useful to distinguish Hemibidessus from other bidessines are the absence of a ventroapical spinula on antennomere 3 and the presence of secondary dorsal setae on protarsus.

Modelling the emergence dynamics of the western corn rootworm beetle (Diabrotica virgifera virgifera).

The western corn rootworm is an invasive species to Europe and is a major agricultural pest that causes widespread economic and yield losses to maize producers. The Gompertz curve was originally used to model human population mortality. It is a sigmoidal curve where the beginning and end of a period shows the slowest time for growth, and adequately describes observed dynamics of many phenomena. We propose the use of the Gompertz function in a Bayesian Hierarchical framework to model the emergence dynamics of the western corn rootworm beetle. The proposed model includes the use of climatic variables to assess how weather can influence the observed dynamics. We apply the model to Austrian monitoring data collected in 2004-2015.