Search Results (111)

Apolygus lucorum (Meyer-Dür) is a phytozoophagous crop pest. While the effects of plant-based diets on its development and reproduction have been extensively studied, the combined effects of plant- and prey-based diets on these traits remain poorly understood. This study systematically evaluated the effects of plant-only, prey-only, and mixed plant–prey diets on A. lucorum nymphal survival and development, as well as adult longevity and fecundity, under controlled laboratory conditions. The results demonstrate that diet composition significantly affected nymphal survival and developmental progression. Nymphs fed exclusively on prey (Aphis gossypii Glover or Bemisia tabaci (Gennadius) nymphs) failed to complete juvenile development. Although a diet of Helicoverpa armigera (Hübner) eggs alone enabled some individuals to reach adulthood, survival rates were significantly lower than those in mixed-diet treatments. Mixed feeding markedly improved nymphal survival, with the highest rates observed in groups fed green beans + H. armigera eggs and cotton leaves + B. tabaci nymph combinations (both 64.45%). The developmental duration was also influenced. Mixed diets, particularly green beans + H. armigera eggs, significantly shortened each instar and the total developmental time (11.04 ± 0.17 d), whereas a diet of cotton leaves alone prolonged development (19.45 ± 0.24 d). Adult longevity and reproductive output were likewise diet-dependent. The longest lifespans were recorded in adults fed green beans alone or green beans + H. armigera eggs, while the shortest lifespan was observed for those fed only cotton leaves. Successful oviposition was only achieved following four dietary treatments: green beans alone, green beans + H. armigera eggs, H. armigera eggs alone, and cotton leaves + H. armigera eggs. Among these, the green bean + H. armigera egg diet yielded the best reproductive performance, featuring the shortest pre-oviposition period (5.82 ± 0.60 d), the longest oviposition period (19.41 ± 1.68 d), and the highest mean fecundity per female (238.35 ± 25.51 eggs). This underscores the reproductive advantage of a mixed plant–prey diet. This study clarifies how dietary conditions shape the survival, development, and reproduction of A. lucorum, highlighting its strong reliance on nutritional quality for key life-history traits. These findings offer valuable insights into the ecological adaptations underlying the feeding behavior of this insect. Full article

Apolygus lucorum, a phytozoophagous mirid bug, plays an important role in the species interactions within fruit tree and cotton ecosystems. Previous research has mainly focused on the phytophagous damage that it causes to crops, while its role as a predator of arthropods remains poorly understood. In this study, we systematically investigated the functional responses of A. lucorum to three crop pests: eggs of Helicoverpa armigera, nymphs of Aphis gossypii, and nymphs of Bemisia tabaci. The results show that the predatory behavior of A. lucorum towards all three prey species followed a Holling type II functional response model. Predatory performance varied significantly depending on prey species, developmental stage, and sex of the mirid. The theoretical maximum predation rate was highest for A. gossypii (833.33 individuals/day) and lowest for B. tabaci nymphs. Adult mirids and older nymphs (4th instar) exhibited higher predation rates than younger nymphs. Field-collected A. lucorum from Bt cotton fields were analyzed using molecular diagnostics, and the result confirmed natural predation on A. gossypii, which was consistent with observed pest occurrence patterns in the field. Overall, this study clarifies the prey selectivity and stage-dependent predatory strategies of A. lucorum, providing insights into its trophic flexibility as a facultative predator. These findings contribute to a more comprehensive understanding of its ecological role in agricultural ecosystems, but do not support its use as a biological control agent given its predominantly phytophagous nature and documented pest status. Full article

In 2024 and 2025, field populations of Aphis gossypii were collected from eight regions in Xinjiang to monitor their resistance levels to five commonly used insecticides: sulfoxaflor, acetamiprid, imidacloprid, abamectin, and chlorpyrifos. The mutation frequencies of five sites in the acetylcholinesterase (AChE) gene (S431F, V332A, A302S, G221A, F139L) and three sites in the β1 subunit of the nicotinic acetylcholine receptor (nAChR) (R81T, V62I, K264E) were also analyzed. The results showed that from 2024 to 2025, the eight A. gossypii field populations exhibited the highest resistance to imidacloprid (primarily moderate to high resistance), followed by acetamiprid (all moderate resistance). Resistance to abamectin and sulfoxaflor was relatively low, but sulfoxaflor resistance increased rapidly (from low resistance in 2024 to moderate resistance in 2025). All populations remained consistently susceptible to chlorpyrifos. Gene analysis revealed that the mutation rate of S431F in the AChE gene was nearly 100%, while that of V332A remained stable at approximately 30%. The mutation rates of A302S and G221A showed a slight increase, whereas the F139L mutation rate was extremely low (<1.00%). In the β1 subunit of nAChR, the mutation rates of R81T and V62I remained stable at around 50%, and the K264E mutation rate was extremely low (<1.00%). This study clarifies the resistance evolution patterns of A. gossypii to different insecticides and the variation characteristics of key resistance genes in Xinjiang, providing a scientific basis for the integrated resistance management of A. gossypii and the rational selection of effective insecticides. Full article

Chrysopa pallens Stephens (Neuroptera: Chrysopidae) is a key predatory species in cotton agroecosystems. This study investigated the prey-mediated sublethal effects of imidacloprid and nitenpyram at low concentrations (LC₂₀), on C. pallens when exposed via consumption of contaminated prey, assessing impacts on its development and predatory function. C. pallens is a key predatory species in cotton agroecosystems. This study investigated the prey-mediated sublethal effects of imidacloprid and nitenpyram (LC₂₀) on the developmental performance and predatory capacity of C. pallens. Leaf-dipping bioassays were used to assess the toxicity of imidacloprid and nitenpyram to Aphis gossypii Glover (Hemiptera: Aphididae). Age-stage, two-sex life table analysis was conducted to evaluate their subsequent effects on the life history traits and predation performance of C. pallens. Imidacloprid was more toxic to A. gossypii than nitenpyram. Sublethal exposure marginally prolonged larval development, but the effect was not statistically significant. Both insecticides significantly extended the pupal stage, with nitenpyram inducing a greater delay. Imidacloprid markedly increased adult longevity, and both compounds significantly reduced female fecundity. Imidacloprid also suppress predatory behavior more potently, decreasing daily adult consumption and reducing first-instar attack rates by approximately 30%. Although all treatments followed a Holling type II functional response, both insecticides increased handling time and reduced searching efficiency. Overall, imidacloprid primarily inhibited predatory performance, whereas nitenpyram more strongly prolonged development and reduced critical population growth parameters. These findings provide essential evidence for ecological risk assessment and for refining the incorporation of natural enemies into cotton integrated pest management (IPM) strategies. Full article

Aphis gossypii (Glover) (Hemiptera: Aphididae) is a significant pest in cotton fields, and the use of both chemical insecticides and natural enemies is a crucial strategy for its management. Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), a predominant predatory natural enemy in cotton fields, plays a vital role in controlling A. gossypii populations. In this study, we investigated the toxicity of four insecticides to both A. gossypii and H. variegata larvae, assessed their field efficacy against A. gossypii, and evaluated their effects on the predatory function of H. variegata larvae. The results revealed that afidopyropen and spirotetramat exhibited relatively high toxicity against A. gossypii, with LC₅₀ values of 13.18 mg/L and 22.17 mg/L, respectively. Flonicamid demonstrated the least toxicity to H. variegata larvae, with an LC₅₀ of 512.66 mg/L. The selectivity toxicity ratios for afidopyropen and flonicamid were 5.05 and 4.73, respectively, indicating strong, favourable selectivity towards H. variegata. The maximum field control efficacy against A. gossypii was 96.76% for afidopyropen and 96.92% for flonicamid. The reduction rates of H. variegata larvae in the afidopyropen treatment plots were relatively low. Among the four treatments, the theoretical predation of third-instar H. variegata larvae against A. gossypii was highest with flonicamid, reaching 215.67. Overall, the four insecticides differed substantially in their combined effects on aphid suppression and predator performance. In particular, afidopyropen and flonicamid provided excellent control of A. gossypii while showing comparatively lower toxicity to H. variegata and causing less impairment of its predatory capacity, indicating a more favourable biological trade-off between pest control and natural enemy conservation. However, laboratory toxicity and functional response assays may not fully capture predator–prey dynamics under complex field conditions; therefore, afidopyropen and flonicamid may be considered suitable candidate insecticides for inclusion in integrated pest management (IPM) programs in cotton systems. Full article

Chinese wolfberry (Lycium barbarum L.), a specialty crop with ecological, medical, and economic value in Ningxia province of China, is subject to severe damage from Aphis gossypii Glover. Currently, A. gossypii populations show extremely high-level resistance to beta-cypermethrin in the major wolfberry planting areas in Ningxia. The specific resistance mechanisms, however, are still not known. In this work, we collected a field A. gossypii strain (HSP) from a wolfberry orchard in Ningxia in 2021 using a single-time sampling method, and its resistance to beta-cypermethrin was determined to be extremely high (994.74-fold) as compared with that of a susceptible strain (SS). Then we explored the potential resistance mechanisms from two aspects, namely, metabolic detoxification and target-site alterations. Bioassays of beta-cypermethrin with or without a synergist showed that piperonyl butoxide (PBO) significantly increased the toxicity of beta-cypermethrin (4.72-fold) to the HSP strain, while triphenyl phosphate (TPP) and diethyl maleate (DEM) exhibited no significant synergistic effects. Correspondingly, the O-demethylase activity of cytochrome P450s in the HSP strain was 1.68-fold higher than that in the susceptive strain (SS), whereas changes in carboxylesterases and glutathione S-transferases activities were unremarkable. Also, fifteen upregulated P450 genes were identified by both RNA-Seq and qRT-PCR technologies, containing eleven CYP6 genes, three CYP4 genes, and one CYP380 gene. Especially, five CYP6 genes with high relative expression levels (>3.00-fold) were intensively expressed by beta-cypermethrin induction in the HSP aphids. These metabolism-related results indicate the key role of P450-mediated metabolic detoxification in HSP resistance to beta-cypermethrin. Sequencing of voltage-gated sodium channel (VGSC) genes identified a prevalent M918L mutation and a new G1012D mutation in HSP A. gossypii. Moreover, heterozygous 918 M/L and 918 M/L + G1012D mutations were the dominant genotypes with frequencies of 60.00% and 36.67% in the HSP population, respectively. Overall, VGSC mutations along with P450-mediated metabolic resistance contributed to the extremely high resistance of the HSP wolfberry aphids to beta-cypermethrin, providing support for A. gossypii control and resistance management in the wolfberry planting areas of Ningxia using insecticides with different modes of action. Full article

Nuclear receptors are a family of ligand-dependent transcription factors that regulate the development, reproduction, survival, and immune responses in insects. However, the structural, biological, and molecular functions of hepatocyte nuclear factor 4 (HNF4) in aphids remain unknown. Aphids are small agricultural pests that directly affect crops due to their rapid reproductive ability, which is influenced by environmental conditions such as temperature, humidity, and photoperiod. In this study, we cloned full-length cDNA encoding HNF4 from the cotton aphid Aphis gossypii (A. gossypii, Hemiptera: Aphididae) (AgHNF4) and investigated its role in regulating lipid metabolic gene expression, aphid survival, and reproduction. Phylogenetic analysis revealed that AgHNF4 shares an evolutionary lineage with other hemipteran insects. The ligand binding domain region of AgHNF4 showed significance in nuclear localization and transcriptional activity. The expression pattern of AgHNF4 was detected in the stages of the aphid life cycle, with notable expression during the 2nd instar, 4th instar, and adult stages. Furthermore, to understand the role of HNF4 in regulating lipid metabolic genes involved in fatty acid synthesis and transport, HNF4-silenced A. gossypii individuals were analyzed. The results showed downregulation of lipid metabolic genes and reduced offspring production and survival rates. Therefore, A. gossypii HNF4 serves as a potential target for regulating lipid metabolism, and targeting HNF4 expression could offer a promising approach to aphid pest control. Full article

Symbiotic bacteria in insects are known to play crucial roles in detoxification metabolism and adaptation to host plant secondary metabolites. In the cotton-growing region of Xinjiang, China, the Ap. gossypii and the Ac. gossypii exhibit significant differences in sensitivity or resistance to pesticides. However, whether their detoxification-related symbiotic bacteria change under insecticide stress remains unclear. This study assessed the toxicity of nitenpyram to both aphid species and the effects of LC₂₀ treatment on their growth, development, and reproduction. Bacterial community dynamics across generations (G0–G2) were analyzed by 16S rRNA gene amplicon sequencing. The LC₂₀ of nitenpyram reduced the longevity and fecundity of the parent generation in both species. In Ap. gossypii, the intrinsic rate of increase (r_m), net reproductive rate (R₀), and finite rate of increase (λ) increased in the G1–G2 generations, whereas these parameters significantly decreased in Ac. gossypii. By the G3 generation, biological parameters in both species showed no significant differences compared to the control. Nitenpyram disrupted the stability of symbiotic bacterial communities in both aphids. In Ac. gossypii, Sphingomonas, a genus with detoxification potential, was consistently suppressed in G1–G2, while the abundance of the primary symbiont Buchnera initially decreased sharply and subsequently recovered. In contrast, the bacterial community in Ap. gossypii remained largely stable. These findings indicate that sublethal concentrations of nitenpyram exert distinct transgenerational effects on the two aphid species and disrupt the stability of their symbiotic bacterial communities. Full article

(1) Objective: To investigate the chemical defense response mechanisms of two cotton (Gossypium hirsutum L., Malvaceae) varieties, Xinlu Zhong 57 and Xinlu Zhong 78, in response to feeding by the cotton aphid (Aphis gossypii Glover, 1877) (Hemiptera: Aphididae) in the Kashi region. (2) Methods: The artificial infestation method was adopted to determine the dynamic changes in the contents of secondary metabolites (tannins, total phenols), activities of protective enzymes (SOD, POD, PPO), and contents of nutrients (soluble sugars, amino acids) in cotton leaves at 0, 24, 48, 72, and 96 h after infestation with cotton aphids. (3) Results: The contents of secondary metabolites and the activities of protective enzymes in both varieties showed an initial increase followed by a decrease. The response of Xinlu Zhong 57 was earlier and stronger. Its tannin and total phenol contents reached a peak at 48 h, with values of 264.2 nmol/g and 5.973 mg/g, respectively, which were significantly higher than those of Xinlu Zhong 78 (p < 0.05). The activities of SOD, POD, and PPO were consistently higher in Xinlu Zhong 57. At 48 h post-inoculation, SOD activity in Xinlu Zhong 57 was 238.1 U/g, significantly higher than in Xinlu Zhong 78 (p < 0.05). POD activity was 49.0 U/g, and PPO activity was 94.5 U/g, both significantly higher than those of Xinlu Zhong 78 (p < 0.05). This suggests that Xinlu Zhong 57 has a stronger ability to scavenge reactive oxygen species. Regarding nutrients, soluble sugar content in Xinlu Zhong 57 was 6.99 mg/g at 96 h, significantly higher than that in Xinlu Zhong 78 (p < 0.05). The amino acid content at 96 h was 224.4 μg/g, also significantly higher than in Xinlu Zhong 78 (p < 0.05). (4) Conclusions: Xinlu Zhong 57 forms a more effective chemical defense system by rapidly activating the defense enzyme system, efficiently accumulating secondary metabolites, and optimizing nutrient allocation. This study provides a theoretical basis for elucidating the physiological mechanisms of cotton resistance induced by cotton aphids by analyzing the effects of cotton aphid stress on the contents of secondary metabolites, protective enzyme activities, and nutrient contents in cotton leaves. Full article

A total of 304 bacterial strains were isolated from the Taklamakan Desert. Through screening, strain TRM82367 exhibited potent insecticidal activity against cotton aphids (Aphis gossypii) and was identified as Bacillus velezensis. To explore the primary insecticidal active components of this strain, lipopeptide substances in the fermentation broth were extracted via hydrochloric acid precipitation. The main active components were analyzed using activity-guided fractionation combined with liquid chromatography–mass spectrometry (LC-MS). Our results demonstrated that Bacillus velezensis TRM82367 possessed strong lethal activity against cotton aphids. The crude extract obtained by means of hydrochloric acid precipitation and methanol dissolution showed high insecticidal efficacy. At concentrations of 100, 150, 200, 250, 300, 400, and 500 mg/L, the 48 h corrected mortality rates of cotton aphids were 25.14%, 38.05%, 50.09%, 53.03%, 57.96%, 74.68%, and 88.67%, respectively. The toxicity regression equation was Y = 2.47X − 5.72, with a median lethal concentration (LC₅₀) of 207.616 mg/L and a 95% lethal concentration (LC₉₅) of 1004.673 mg/L. After separation by an ODS chromatographic column and identification by means of mass spectrometry, the main active components were confirmed to be C₁₂–C₁₆ surfactin homologs. Full article

The cotton aphid Aphis gossypii is a globally significant agricultural pest that threatens crop production through its prolific reproduction. While the parasitoid wasp Binodoxys communis offers promising potential for biological control, the molecular mechanisms underlying its reproductive manipulation of aphid hosts remain poorly understood. Here, we investigated the stage-specific parasitism strategies of B. communis on A. gossypii using integrated biological observations and transcriptomic analysis. Parasitism significantly prolonged aphid development and suppressed reproduction across all host stages, with severity inversely correlated with host age at parasitism. Transcriptomic analysis of ovaries of parasitized aphids revealed 1168 differentially expressed genes, with temporal progression from minimal changes in nymphs (7 DEGs at day 1) to extensive disruption in adults (549 DEGs at day 3). Notably, juvenile hormone acid methyltransferase (JHAMT), the rate-limiting enzyme in juvenile hormone biosynthesis, emerged as a master regulator that is differentially targeted across host stages. In 3rd instar nymphs, single-gene suppression of JHAMT (−3.23-fold change) achieved effective reproductive control, whereas adult parasitism required progressive manipulation of multiple genes including JHAMT, FOHSDR, ALDH, and JHEH. The vitellogenin-vitellogenin receptor system only showed coordinated downregulation in adults, whereas nymphs exhibited preemptive receptor suppression before vitellogenesis onset. These findings demonstrate that B. communis has evolved to exploit a developmental window where host manipulation is most efficient—3rd instar nymphs, which possess sufficient resources for parasitoid development and lack the complex compensatory mechanisms found in adults. This “low-cost, high-reward” strategy based on precision targeting of master regulators in nymphs compared to multi-gene assault in adults, revealing the evolutionary optimization of parasitoid manipulation strategies. Our results provide molecular insights into parasitoid-host coevolution and identified key regulatory targets for developing innovative biological control strategies against this important agricultural pest. Full article

Aphis gossypii is a major pest that harms crops like industrial tomatoes in Panama. Recent resistance to synthetic insecticides has prompted interest in using plant secondary metabolites as eco-friendly alternatives. While some plants with insecticidal properties are well-known, others remain unexplored but could offer effective solutions. This study aimed to evaluate the insecticidal activity of ethanolic extracts from the stems and leaves of Eschweilera jefensis against nymphs and adults of Aphis gossypii. Extracts were tested at three concentrations (25, 50, and 100 µg/L), with mortality assessed at 24, 48, and 72 h post-application. The LC₅₀ values for the stem extract were 66.5, 36.8, and 31.0 μg/L, and for the leaf extract, they were 37.3, 28.4, and <25 μg/L at 24, 48, and 72 h, respectively. An advanced metabolomic analysis was conducted to identify the active compounds in each extract. This analysis uncovered several pentacyclic triterpenes, which, known for their insecticidal properties, are likely the key bioactive components responsible for the observed effects. Advanced metabolic analyses also revealed that the leaf extract, displaying the strongest insecticidal activity, is primarily composed of friedelin, while the stem extract contains betulin as their key active compounds. Furthermore, 29 known compounds were identified across both extracts, representing the first comprehensive report on the metabolic composition of E. jefensis, which underscores the significance of these findings. Together, these results suggest that E. jefensis extracts could serve as a promising natural alternative to synthetic insecticides for the management and control of A. gossypii. Full article

The aphid, Aphis gossypii Glover, and the leaf beetle, Lema decempunctata Gebler, are two catastrophic pests affecting the production of the organic goji berry, Lycium barbarum L. Our previous studies have demonstrated that the defense responses of goji berry induced by aphid infestations can facilitate the growth and development of beetles. However, the reciprocal effects of these two insect infestations on aphids remained unclear. In this study, the impacts of these two pest infestations on the development, survival, and reproduction of aphids were examined. Additionally, the levels of plant defense-related hormones, salicylic acid (SA) and jasmonic acid (JA), were measured. Subsequently, host plants were treated with two hormone analogues, 2, 1, 3-benzothiadiazole (BTH) and methyl jasmonate (Me-JA), to identify their effects on aphid development, survival, and reproduction. The results showed that the total developmental duration was accelerated by 33.60%, and the total reproduction of aphids was increased by 82.98% compared to the control after aphid infestation, without influencing survival. In contrast, the beetle infestation did not significantly influence any aspect of the aphid population. The content of SA in plants after the aphid infestation and JA after the beetle infestation increased 19.42 times and 400.50 times, respectively, compared with the control. The total developmental duration of aphids treated with BTH was reduced by 13.44%, while their reproduction increased by 60.52% compared with the control. The total developmental duration of aphids treated with Me-JA was prolonged by 23.51% compared to the control, while survival rates and reproduction were unchanged. Our research elucidates the intricate interspecific relationship between A. gossypii and L. decempunctata, providing valuable insights into the complex interspecific relationship between the two pests and informing effective strategies for their scientific prevention and control. Full article

The cotton aphid, Aphis gossypii Glover, is among the most economically significant sap-sucking insect pests, inflicting substantial economic losses worldwide. Insecticides such as thiamethoxam, bifenthrin, and flonicamid are commonly used to manage this pest, despite the inherent risk of developing resistance. In this study, we investigated the evolution of insecticide resistance in A. gossypii after continuous selection with thiamethoxam, bifenthrin, and flonicamid over more than ten generations in a controlled laboratory environment. We assessed the fitness of resistant strains using an age-stage, two-sex life table approach, comparing them to a susceptible population. The results indicated that A. gossypii achieved resistance levels of 158.60-fold against thiamethoxam, 129.18-fold against bifenthrin, and 104.75-fold against flonicamid. Furthermore, life table analyses revealed that the developmental stages were significantly extended, while longevity decreased in all resistant strains compared to the susceptible population. Additionally, the net reproductive rate (R₀), fecundity, and reproductive days were notably reduced in the resistant cohorts when compared to the susceptible strain. Overall, these findings provide valuable insights into the laboratory-induced evolution of insecticide resistance and the associated fitness costs in A. gossypii when feeding on cotton plants. This information could be instrumental in formulating effective resistance management strategies to control this significant pest. Full article

Aphis gossypii is a significant global pest that impacts numerous agricultural crops and vegetables, causing direct damage to food plants and indirect damage through the transmission of phytopathogenic viruses, primarily begomoviruses. In Panama, particularly in the Azuero region, viral infections transmitted by this aphid can affect a substantial share of tomato crops cultivated for industrial use. A traditional alternative to synthetic pesticides involves exploring plant extracts with insecticidal properties derived from wild plants found in our tropical forests, which can be easily prepared and applied by farmers. In this context, the present research aimed to evaluate the insecticidal activity of ethanolic extracts from the stems and leaves of Sphagneticola trilobata on both nymphs and adults of A. gossypii. Mortality was assessed at 24, 48, and 72 h after applying three doses of each extract (25, 50, and 100 µg/L). A standard phytochemical analysis to determine insecticidal activity revealed that both extracts exhibited significant efficacy at the highest concentration tested; however, the leaf extract demonstrated greater effectiveness at lower concentrations. A comprehensive metabolomic study indicated that the active compounds are diterpenes derived from the pimarenyl cation. These compounds have been extensively documented for their insecticidal potential against various insect species, suggesting that ethanolic extracts from this plant could serve as viable candidates for agricultural insecticides to combat aphid infestations. Full article