Search Results (61)

A comprehensive annotated checklist of the members of the phytophagous ladybird beetle tribe Epilachnini (Coccinellinae) in China is compiled based on existing published sources and incorporates the latest taxonomic and nomenclatural updates. The checklist documents 176 extant species across 10 genera and provides analyses of regional species richness, distribution, and host plant associations. Regarding regional species richness, Yunnan Province is home to the highest number of species (76), followed by Taiwan (50), Sichuan (48), Guizhou (48), Guangxi (43), Tibet (43), Guangdong (25), Hainan (17), Hubei (17), Hunan (13), Shaanxi (13), Fujian (12), Henan (10), Jiangsu (10), Anhui (7), Shandong (7), Zhejiang (7), Jiangxi (5), Hong Kong (5), Gansu (5), Beijing (4), Hebei (4), Liaoning (3), Shanxi (2), and Chongqing, Jilin, Heilongjiang, Ningxia, and Xinjiang (each with one species). Among the recognized genera, Epilachna Chevrolat, 1837, is currently the most species-rich genera, with 59 species, followed by Afissa Dieke, 1947 (34), Uniparodentata Wang & Cao, 1993 (28), Henosepilachna Li, 1961 (29), Afidentula Kapur, 1958 (10), Diekeana Tomaszewska & Szawaryn, 2015 (9), and Epiverta Dieke, 1947 (4). Additionally, Afidenta Dieke, 1947, Cynegetis Chevrolat, 1837, and Subcoccinella Agassiz & Erichson, 1845 are each represented by a single species. Host plant data are currently available for only 72 species (approximately 41% of the species recorded in China), which are associated with 177 plant species across 34 families. The most frequently recorded host plant families are Solanaceae (43 species), Cucurbitaceae (32), Urticaceae (15), Fabaceae (14), Asteraceae (14), and Poaceae (10), whereas each of the remaining 28 families comprises fewer than 10 host species. For 104 species (59% of the Chinese members of the tribe), host plant associations remain unknown, highlighting a substantial gap in our understanding of their feeding habits. Full article

Delphastus Casey (Coleoptera: Coccinellidae: Serangiini) comprises small predatory ladybird beetles that feed on immature whiteflies. Several Delphastus species are utilized as biological control agents. However, Delphastus pallidus (LeConte) has been understudied for the past several decades. Recent landscape surveys in South Florida revealed a marked increase in D. pallidus populations associated with multiple whitefly species. We evaluated whitefly species preferences of D. pallidus using choice and no-choice assays conducted in incubators and insectaries. Seven whitefly species were confirmed as prey and ranked in order of preference: Bemisia tabaci Gennadius > Aleurothrixus trachoides (=Aleurotrachelus trachoides) (Back) > Singhiella simplex (Singh) > Paraleyrodes bondari Peracchi > Aleurodicus rugioperculatus Martin > Asiothrixus antidesmae (Takahashi) > Aleurodicus dugesii Cockerell. Findings indicate that D. pallidus feeds on a taxonomically and morphologically diverse set of whiteflies, including both waxy and non-waxy species, which likely facilitates establishment and dispersal in ornamental and agricultural landscapes. This study is the first to document D. pallidus as a potentially native U.S. predatory beetle that attacks at least seven whitefly species. Knowledge of its prey preferences will inform mass-rearing strategies and potential deployment for whitefly biocontrol. Full article

Ladybird beetle, Serangium japonicum (Coleoptera: Coccinellidae), is an important predatory natural enemy of whiteflies, and its mass rearing is crucial for biological control. This study evaluated the suitability of Corcyra cephalonica (Lepidoptera: Pyralidae) eggs as an alternative diet for adult S. japonicum by directly comparing it to the natural prey, Bemisia tabaci (Hemiptera: Aleyrodidae) nymphs. Results showed that, compared to a B. tabaci diet, feeding on C. cephalonica eggs supported normal development and significantly extended the lifespan of adult S. japonicum, without compromising offspring quality (hatching rate, development, survival, or predatory capacity). However, the moth egg diet significantly impaired reproduction, causing delayed ovarian development, reduced vitellogenesis, and altered gene expression: downregulation of methoprene-tolerant, Juvenile hormone acid O-methyltransferase, Vitellogenin, and Vitellogenin receptor, and upregulation of Juvenile hormone esterase and Copper/zinc superoxide dismutase. Practically, this work defines C. cephalonica eggs as a suboptimal but viable supplementary diet for colony maintenance, but unsuitable as a sole diet for mass-rearing reproductively robust populations. Our findings explain the physiological and molecular mechanisms underlying the “reproduction–lifespan trade-off” in S. japonicum induced by feeding on C. cephalonica eggs, providing a mechanistic basis for its rational application in the mass production of natural enemies. Full article

Light is a fundamental ecological cue for insects, influencing physiological rhythms and behavior. We investigated how varying light intensities affect locomotion and foraging in H. axyridis color morphs, and examined the role of visual opsins. Three adult female morphs were assayed under white light at 1000, 5000, and 10,000 lx. Higher light intensity significantly elevated body temperature and locomotor activity across morphs, with the inherently dark f. conspicua morph exhibiting the greatest increases. Predation rates on pea aphids trended upward with intensity but differed significantly by morph: f. conspicua beetles consistently consumed more prey than f. succinea. RNAi knockdown of the UV-sensitive opsin HaUVSop-2 significantly reduced the crawling distance of satiated beetles under 5000 lux white light. Correspondingly, supplementation of white light with blue light (short wave) enhanced movement, whereas red supplementation increased aphid consumption. These results suggest that Short-wavelength light has the potential to stimulate the dispersal of ladybirds, whereas long-wavelength light may enhance predation on prey by increasing microenvironment temperature or improving prey recognition. We conclude that light intensity and spectrum jointly modulate H. axyridis behavior in a morph-dependent manner, mediated in part by visual opsins. Melanic morphs leverage thermal melanism to gain higher activity under bright light, implying an evolved trade-off between dispersal and stress tolerance. Our findings have practical implications: tailored lighting (e.g., blue-enhanced illumination to stimulate predation and dispersal of H. axyridis) could improve biological control efficacy in agroecosystems. Full article

Paracoccus marginatus (Hemiptera: Pseudococcidae) poses a significant threat to over 200 plant species, severely impacting agricultural productivity. Diomus guilavoguii (Coleoptera: Coccinellidae) is a natural predator of P. marginatus. To develop an effective and environmentally friendly management strategy against P. marginatus, this study investigates the predation relationship between D. guilavoguii and P. marginatus by focusing on functional response and mutual interference under controlled laboratory conditions (Petri dishes). The results indicated that D. guilavoguii exhibits a type II functional response toward P. marginatus, with adults of D. guilavoguii demonstrating superior efficiency in preying upon P. marginatus (the theoretical daily maximum predation rate for female adults of D. guilavoguii on young mealybugs is 416.667). However, a decrease in the predators’ search effect was observed with increasing prey density. Additionally, interspecific interference competition intensified as the number of predators increased, resulting in reduced predation efficiency. Consequently, D. guilavoguii shows promise biological control agent for the management of P. marginatus under laboratory conditions, although further studies in greenhouse and field environments are required to validate its potential in practical pest management. Full article

Five beetle species can occur in potato fields simultaneously, including one quarantine pest (the Colorado potato beetle (CPB)), one phytophagous pest (the 28-spotted potato ladybird beetle), and three predatory ladybird beetles (the 7-spotted lady beetle, the tortoise beetle, and the harlequin ladybird beetle). The timely detection and accurate identification of CPB and other phytophagous or predatory beetles are critical for the effective implementation of monitoring and control strategies. However, morphological identification requires specialized expertise, is time-consuming, and is particularly challenging due to the dark brown body color of these beetles when in the young larval stages. This study provides an effective solution to distinguish between phytophagous and/or quarantine and predatory beetles. This solution is in the form of a new convolutional neural network architecture, known as MSAC-ResNet. Specifically, it comprises several multiscale asymmetric convolution blocks, which are designed to extract features at multiple scales, mainly by integrating different-sized asymmetric convolution kernels in parallel. We evaluated the MSAC-ResNet through comprehensive model training and testing on a beetle image dataset of 11,325 images across 20 beetle categories. The proposed recognition model achieved accuracy, precision, and recall rates of 99.11%, 99.18%, and 99.11%, respectively, outperforming another five existing models, namely, AlexNet, MobileNet-v3, EfficientNet-b0, DenseNet, and ResNet-101. Notably, the developed field investigation mini-program can identify all the developmental stages of these five beetle species, from young larvae to adults, and provide timely management (or protection) suggestions to farmers. Our findings could be significant for future research related to precise pest control and the conservation of natural enemies. Full article

The ladybird beetle, Henosepilachna vigintioctopunctata, is an oligophagous pest with significant economic impact. This pest causes considerable economic damage on numerous Solanaceae crops. Neuropeptides, along with their designated receptors, play a pivotal role in regulating diverse biological processes in insects, presenting a promising avenue for innovative pest management strategies. Herein, the transcriptome of the central nervous system (CNS) of H. vigintioctopunctata was sequenced. Overall, our analysis identified 58 neuropeptide precursor genes, from which 98 diverse mature peptides were predicted. Furthermore, 31 neuropeptide receptor genes belonging to three distinct classes were discovered, along with predictions for their potential ligands. Moreover, the expression patterns of these 58 neuropeptide genes across larval brain tissue, ventral nerve cord, and gut were evaluated using quantitative real-time PCR. Collectively, these findings will significantly contribute to future research focused on understanding the physiological functions and pharmacological characteristics of neuropeptides and their receptors in H. vigintioctopunctata. Ultimately, these insights may facilitate the development of targeted neuropeptide-based solutions for managing this pest affecting solanaceous plants. Full article

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