Search Results (53)

The ladybird beetle, Propylea japonica Thunberg (Coleoptera: Coccinellidae), is a widely distributed natural predator that is crucial in controlling various agricultural pests in China. Despite frequent references to its remarkable thermotolerance, the molecular mechanisms underlying its thermotolerance remain poorly understood. Here, we investigated metabolomic changes in P. japonica following exposure to acute heat stress (AHS) lasting 1 h at 39 °C and 43 °C in populations from Zhengzhou (ZZ, warm temperate climate zone) and Shenzhen (SZ, subtropical climate zone), representing distinct northern and southern Chinese ecosystems. A total of 4165 and 4151 metabolites were detected in positive and negative ion modes, respectively. The high proportion of lipid and lipid-like metabolites (35.5%) and the top 20 pathways containing the highest number of metabolites, implying membrane fluidity modulation and energy metabolism restructuring, served as the core adaptive mechanism in P. japonica populations confronting thermal stress. The SZ25 vs. SZ39 exhibited a significantly higher number of differentially expressed metabolites (DEMs), which were predominantly enriched in the purine and tryptophan metabolism pathways. This indicated that these pathways orchestrate thermal adaptation in the SZ population by coordinating energy metabolism reprogramming, orchestrating antioxidant defense mechanisms, and modulating neuroendocrine homeostasis dysregulation. Additionally, the starch and sucrose, arachidonic acid, and fructose and mannose metabolism pathways were also implicated. This study enhances our understanding of P. japonica thermotolerance and provides a valuable reference for thermotolerance mechanisms in other insects. Full article

The endemic African genus Epipleuria Fürsch is re-described, diagnosed and confronted with African species of the closely related genus Rhyzobius Stephens. The validity of the genus Epipleuria is confirmed. Two new species, Epipleuria capensis sp. nov. and Epipleuria tsitsikamma sp. nov., from the Republic of South Africa are described. Additionally, the male genitalia of Epipleuria natalensis Fürsch, 2001, are described and illustrated for the first time. Epipleuria endroedyi Fürsch, 2001; Epipleuria mahnerti Fürsch, 2001; and Rhyzobius stillatus Fürsch, 1992, are transferred to the newly established genus Pseudoepipleuria gen. nov. Full article

The cotton–melon aphid (Aphis gossypii Glover), a globally distributed polyphagous pest, primarily infests cucurbit crops and leads to significant reductions in both crop yield and quality. Overreliance on chemical insecticides has resulted in widespread resistance development, highlighting the urgent requirement for alternative control strategies. This study evaluates the potential of topical RNA interference (RNAi) for managing cotton–melon aphids. We first analyzed instar-specific expression profiles of four candidate RNAi target genes (ATPE, IAP, Cat, and ilvE), employed topical dsRNA delivery to silence these genes, and subsequently evaluated their effects on aphid mortality, growth rates, and reproductive capacity. Furthermore, we investigated the non-target effects of RNAi-treated aphids on the predator ladybird beetles Propylea japonica. The results indicate that topical dsRNA delivery successfully silenced the target genes, significantly impairing aphid development and fecundity while inducing mortality, with no adverse effects on the beneficial predator. This method provides a powerful tool for insect gene functional studies and a promising solution for RNAi-based pest management. Full article

The Asian citrus psyllid, Diaphorina citri, serves as the primary vector for Huanglongbing (HLB) by transmitting Candidatus Liberibacter asiaticus. Lambda-cyhalothrin and thiamethoxam are commonly employed for the control of D. citri. The multicolored Asian lady beetle, or harlequin ladybird, Harmonia axyridis, is an important predator of D. citri in both greenhouse and field settings. The effectiveness of integrated pest management (IPM) relies on the judicious use of selective insecticides that minimize harm to natural enemies. However, the effects of these insecticides on H. axyridis’ predation of D. citri remain thoroughly unexplored. In this study, we assessed the toxicity of lambda-cyhalothrin and thiamethoxam to H. axyridis and examined their impact on the functional response of this predator to D. citri using direct contact exposure methods. We also evaluated the indirect effects on predator voracity through ingestion exposure. Our results demonstrated that exposure to both insecticides at LC₅₀ concentrations significantly prolonged the developmental durations of H. axyridis larval stages. The type-II functional response model effectively described the prey consumption patterns of H. axyridis, revealing a significant reduction in predation capacity across all life stages, particularly among second instar larvae, which experienced reductions of 85.30% and 88.58% following lambda-cyhalothrin and thiamethoxam treatments, respectively. Furthermore, H. axyridis’ predation significantly declined when feeding on D. citri contaminated at LC₅₀ concentrations. These findings indicate that lambda-cyhalothrin and thiamethoxam adversely affect the predation of H. axyridis, both via direct contact and ingestion. Evaluating the potential impacts of these insecticides on H. axyridis is critical for the development of effective IPM strategies targeting D. citri. Full article

The conservation of the predatory ladybird beetle, Eriopis connexa (Germar) after its release also relies on its resistance and the performance of its progenies. When resistant individuals are released or evolve in the field through mating with susceptible pairs, we anticipate that they will generate a resistant progeny, inheriting the resistance to lambda-cyhalothrin through an autosomal mechanism. The susceptibility of a field-collected population (EcGA) was characterized and determined by the performance of their progenies generated through mating with a resistant parent (EcViR). We paired virgin adults from the EcGA and EcViR populations, observing how their progenies developed, reproduced, and survived when exposed to dried lambda-cyhalothrin residues applied at field rates. Adults from the EcGA population were ~200-fold more susceptible than those of the EcViR population. Developmental times from larva to adult emergence for EcGA individuals were delayed by approximately 6 days and generated smaller adults compared to EcViR and their progenies. The egg production did not differ across parents and progenies, but females from EcGA and EcGA × EcViR progenies produced 130 more eggs in comparison to EcViR females during the 35-day evaluation period. Exposure to lambda-cyhalothrin resulted in 77.4 to 100% survival for adults from EcViR × EcGA progenies and EcViR parents, while EcGA and the population standard for susceptibility maintained in the laboratory (EcFM) did not survive the insecticide exposure. These findings indicate that field crosses between EcViR and EcGA will improve their progenies’ biological performance compared to the EcViR parents and will maintain a high lambda-cyhalothrin survival rate. Full article

Physalis floridana Rydb., a member of the Solanaceae family, is renowned for its diverse secondary metabolites, including physalins and withanolides. The 28-spotted ladybird beetle (Henosepilachna vigintioctopunctata) is a notorious pest severely damaging Solanaceous crops. This study demonstrates that P. floridana Rydb. significantly impacts on the development and reproductive suppression of H. vigintioctopunctata. A comparative transcriptome analysis was performed by feeding H. vigintioctopunctata larvae on P. floridana Rydb., Solanum nigrum L., Solanum tuberosum L., and Solanum lycopersicum L. The results reveal that larvae fed on P. floridana Rydb. exhibit numerous differentially expressed genes, which are notably enriched in pathways related to energy metabolism, immunity, and detoxification. These functions and pathways are less enriched in larvae fed by other hosts. Weighted Gene Co-expression Network Analysis (WGCNA) indicates that feeding on P. floridana Rydb. influences the expression of specific genes involved in the Toll and IMD signaling pathways, impacting the immune system of H. vigintioctopunctata larvae. This study provides transcriptomic insights into larval responses to different diets and suggests that the effect of P. floridana Rydb. on the immune system of H. vigintioctopunctata is a key defense mechanism against herbivores. Full article

This study investigates the species richness and distribution of ladybird beetles (Coccinellidae) across various habitats on San Cristóbal Island in the Galápagos Archipelago, Ecuador. Through extensive field surveys, we catalogued nineteen species, including four previously known species (two endemics, Psyllobora bisigma and Scymnobius scalesius, and two natives, Cycloneda sanguinea and Tenuisvalvae bromelicola). We also identified nine possibly native species reported for the first time in the Galapagos islands in this study or correspond to the first voucher specimens for the island. We collected three previously reported non-native species: Cheilomenes sexmaculata, Novius cardinalis, and Paraneda guticollis. Three species belonging to the genera Stethorus, Calloeneis, and Delphastus remain undetermined, pending further taxonomic analyses. Our findings reveal a rich and complex community with notable differences in species abundance and habitat preference. Endemic species were found to be particularly scarce and restricted mainly to crops undergoing forest regeneration and deciduous forests, emphasising their vulnerability and specialised habitat requirements. The native Cycloneda sanguinea emerged as the most prevalent species, exhibiting broad ecological adaptability. Non-native species, like Cheilomenes sexmaculata, were predominantly found in disturbed habitats, with some showing early signs of spreading into more natural environments, raising concerns about their potential impact on local biodiversity. These findings contribute valuable knowledge to understanding Coccinellidae diversity on San Cristóbal Island and highlight the importance of continued monitoring, particularly in the face of ongoing environmental change and the introduction of non-native species. This study underscores the need for targeted conservation efforts to protect the unique and fragile ecosystems of the Galápagos Archipelago. Full article

Eukaryotic genomes exhibit a dynamic interplay between single-copy sequences and repetitive DNA elements, with satellite DNA (satDNA) representing a substantial portion, mainly situated at telomeric and centromeric chromosomal regions. We utilized Illumina next-generation sequencing data from Adalia bipunctata to investigate its satellitome. Cytogenetic mapping via fluorescence in situ hybridization was performed for the most abundant satDNA families. In silico localization of satDNAs was carried out using the CHRISMAPP (Chromosome In Silico Mapping) pipeline on the high-fidelity chromosome-level assembly already available for this species, enabling a meticulous characterization and localization of multiple satDNA families. Additionally, we analyzed the conservation of the satellitome at an interspecific scale. Specifically, we employed the CHRISMAPP pipeline to map the satDNAs of A. bipunctata onto the genome of Adalia decempunctata, which has also been sequenced and assembled at the chromosome level. This analysis, along with the creation of a synteny map between the two species, suggests a rapid turnover of centromeric satDNA between these species and the potential occurrence of chromosomal rearrangements, despite the considerable conservation of their satellitomes. Specific satDNA families in the sex chromosomes of both species suggest a role in sex chromosome differentiation. Our interspecific comparative study can provide a significant advance in the understanding of the repeat genome organization and evolution in beetles. Full article

This paper provides new data on the ladybird beetles (Coccinellidae) from two islands in the Canary archipelago: Tenerife, the largest island, and La Gomera, the second smallest. As they clearly differ in size but are similar in location and geological age, they are a suitable model for testing the species–area relationship. Our study shows that, in line with this main assumption of the theory of island biogeography, clearly more species occur on a large island (Tenerife) than on a small one (La Gomera). The field surveys documented the occurrence of 35 ladybird species on Tenerife (including 5 not previously reported from this island) and of 20 species on La Gomera (2 species new to the island). Coelopterus sp. collected on Tenerife (a single female that could not be identified to species) is the first record of this genus for the whole Canary Islands. Taking our data and previously published records into account, 47 species of Coccinellidae are known to occur on Tenerife and 26 species on La Gomera. Tenerife has by far the richest ladybird fauna of all the Canary Islands (the next in line, Gran Canaria, has 41 recorded species), but it also has the highest number of non-native ladybird species. All of the ten non-native species recorded in the Canary Islands are found on Tenerife, and for most of them, Tenerife was the island of their first appearance in the archipelago. This island, much more distant from the mainland than the other relatively large islands (Fuerteventura, Lanzarote), appears to be the main recipient of ladybirds immigrating to the Canary Islands. Tenerife can play this role probably because of its great habitat diversity and altitude variation, as well as intensive tourism and trade-related transport. Full article

Botanical insecticides and soaps are frequently proposed as environmentally safer alternatives to synthetic insecticides. However, the efficacy and selectivity of these products are often only partially supported by empirical evidence. Here, we tested the effectiveness of five botanical insecticides, belonging to different categories, on the green peach aphid Myzus persicae (Sulzer) and their selectivity towards two natural enemies, the ladybird beetle Propylea quatuordecimpunctata (L.) and the parasitoid Aphidius colemani (Dalman). White thyme essential oil (EO), sweet orange EO, crude garlic extract and Marseille soap were tested and compared with a pyrethrin-based commercial product. Both direct spray assays and residual contact assays on treated cabbage leaf disks were carried out. The tested products had low efficacy against aphids when compared to pyrethrins but were in general less detrimental to ladybird beetle larvae, meaning that if applied against other pests, they have a lower chance of harming this agent of aphid biocontrol. Some of the products (soap, orange EO) did, however, show direct exposure toxicity toward ladybird larvae, and thyme EO had extensive phytotoxic effects on cabbage leaves, possibly indirectly leading to higher mortality in ladybird adults. These results underline the necessity for case-by-case evaluations of botanical insecticides. Full article

The beetle, of the order Coleoptera, possesses outstanding flight capabilities. After completing flight, they can fold their hindwings under the elytra and swiftly unfold them again when they take off. This sophisticated hindwing structure is a result of biological evolution, showcasing the strong environmental adaptability of this species. The beetle’s hindwings can provide biomimetic inspiration for the design of flapping-wing micro air vehicles (FWMAVs). In this study, the Asian ladybird (Harmonia axyridis Pallas) was chosen as the bionic research object. Various kinematic parameters of its flapping flight were analyzed, including the flight characteristics of the hindwings, wing tip motion trajectories, and aerodynamic characteristics. Based on these results, a flapping kinematic model of the Asian ladybird was established. Then, three bionic deployable wing models were designed and their structural mechanical properties were analyzed. The results show that the structure of wing vein bars determined the mechanical properties of the bionic wing. This study can provide a theoretical basis and technical reference for further bionic wing design. Full article

The eggs of the Mediterranean flour moth, Ephestia kuehniella, are frequently utilized as alternative diets and have demonstrated promising outcomes when consumed by various insects. Nonetheless, the specific reasons for their effectiveness remain unclear. In our study, we assessed the developmental performance of the ladybird Propylea japonica when fed E. kuehniella eggs, alongside 12 factitious prey or artificial diets. Our findings revealed that ladybirds fed E. kuehniella eggs displayed a performance comparable to those fed the natural prey Megoura crassicauda. Transcriptome profiling of larvae raised on E. kuehniella eggs and M. crassicauda revealed that genes upregulated in the former group were enriched in metabolic pathways associated with carbohydrates, lipids, and other essential nutrients. This suggests that E. kuehniella eggs may have a higher nutrient content compared to natural prey. Furthermore, a notable downregulation in the expression of immune effector genes, such as Attacin and Coleoptericin, was observed, which might be attributed to the lower microbial content in E. kuehniella eggs compared to M. crassicauda. We suggest that the difference between E. kuehniella eggs and M. crassicauda as food sources for P. japonica lies in their nutrient and microbial contents. These findings provide valuable insights for the advancement of innovative artificial breeding systems for natural enemies. Full article

Many insects are able to walk vertically or upside down on both hard and soft surfaces. In beetles such as the ladybird (Coccinella septempunctata), intermolecular forces between tarsal setae on the footpads of the insects make this movement possible. In prior work, adhesion structures made from polydimethylsiloxane (PDMS) that mimic the action of the tarsal setae have been developed. It is proposed that these adhesion structures could be attached to a simplified version of the leg of a ladybird and used in practical applications. For example, the leg structures could potentially be employed in small surveillance drones to enable attachment to surfaces during flights, in order to preserve battery power. Alternatively, the structures could be used in small robotic devices to enable walking on steeply inclined surfaces. In this program of work, the morphology and movement of the leg of a ladybird were closely studied using a 3D X-ray microscope and a high-speed microscope. The positions of the tendons that facilitated movement were identified. From this knowledge, a simplified leg structure using pin-joints was designed and then fabricated using 3-D printing. The PDMS adhesion structures were then attached to the leg structure. The tendons in the actual insect leg were replicated using thread. Typical detachment forces of about 4 N indicated that the simplified leg structure was, in principle, more than capable of supporting the weight of a small device and then detach successfully. Attachment/detachment movement operations were performed using a linear actuator and controlled remotely. Therefore, proof of concept has been demonstrated for the use of such a simplified ladybird leg structure for the attachment/detachment of small robotic devices to horizontal, inclined, or vertical surfaces. Full article

The morphological diversity of insect mouthparts is closely related to changes in food sources and diets. Research into the structures of insect mouthparts may help to establish a fundamental basis for a better understanding of insect feeding mechanisms. In this study, we examined the fine morphology of the mouthparts of Illeis chinensis using scanning electron microscopy. We paid particular attention to the types, quantities, and distribution of sensilla on the mouthparts. Our results showed that the basic components of the mouthparts of I. chinensis are the same as those in other lady beetles, i.e., the labrum, mandible, maxillae, labium, and hypopharynx. We also found structural specialization indicating adaptation to fungal feeding. On the mouthparts, there are eight kinds of sensilla and two kinds of glandular structures, including sensilla chaetica, sensilla basiconica, sensilla styloconica, sensilla coeloconica, sensilla campaniformia, sensilla placodea, sensilla digitiformia, Böhm bristles, perforated plates, and cuticular pores. This is the first time that sensilla digitiformia has been reported in ladybirds. Finally, variations in mouthparts among ladybirds with differing diets, as well as the putative functions of each of the mouthparts and sensilla, were discussed. This research can provide a reference for understanding the functions of the mouthparts in ladybird feeding behavior and thereby contribute to the development of precise insect behavior regulation and management strategies. Full article