Search Results (1,122)

Sorghum (Sorghum bicolor L. Moench) is one of the most important cereal crops in Mexico due to its extensive cultivation and use in human nutrition, livestock production, and the biofuel industry. However, its productivity is severely affected by the sorghum aphid, Melanaphis sorghi Theobald, 1904 (Hemiptera: Aphididae), a major pest of this crop. Its control relies primarily on synthetic chemical insecticides, whose intensive use has led to environmental impacts and health risks, prompting the search for more sustainable alternatives. In this study, the insecticidal activity of root extracts from Bessera elegans was evaluated against apterous adults of M. sorghi using artificial diet bioassays at different concentrations and exposure times. Chemical characterization of the extracts and the active fraction was carried out using high-performance liquid chromatography (HPLC) and gas chromatography coupled to mass spectrometry (GC–MS). The methanolic extract exhibited the lowest LC₅₀ value (2562 ppm), indicating the highest insecticidal potency, while the acetone extract achieved the highest maximum mortality (98%) at the highest tested concentration. Fractionation of the methanolic extract allowed the identification of fraction BeF1 as the most active, with 94% mortality at 1000 ppm. Chemical characterization indicated a predominance of polyphenolic secondary metabolites, mainly flavonoids and lignans. These results highlight the potential of B. elegans as a natural alternative for the integrated management of the sorghum aphid. Full article

Insects underpin key ecosystem services. Yet tree-associated insect communities remain comparatively poorly documented, particularly in temperate forests. This study aimed to characterize the diversity and abundance of insect assemblages associated with the predominantly insect-pollinated forest tree Tilia cordata Mill. in protected areas in Lithuania, and to assess the occurrence of known and putative pollinator groups within these assemblages. We quantified insect assemblages associated with Tilia cordata using two sampling methods but did not directly measure pollination effectiveness (e.g., pollen loads, visitation rates to flowers, or fruit/seed set). Consequently, our inferences refer to the presence and composition of potential pollinators rather than demonstrated pollination function or realized pollination services. Fieldwork was conducted over two years in six protected T. cordata sites in Lithuania using two complementary sampling methods: net sampling and sticky traps. Sampling was structured into three observation periods corresponding to T. cordata phenology: pre-flowering (I), flowering (II) and post-flowering (III). In total, 207 insect taxa from 15 orders were recorded by net sampling and 86 taxa from 11 orders by sticky traps. Net sampling showed significantly higher diversity (Shannon H = 3.81) than sticky traps (H = 2.10). Hemiptera, Coleoptera and Diptera were the most common groups, and most taxa occurred at low to moderate abundances, with only a few species showing local dominance in specific periods or sites. Taxa documented in the literature as significant pollinators were consistently present but at low relative abundances (about 5–10% in total). Insect assemblage composition and species proportions varied among phenological periods and between years, with no clear, consistent peak in overall insect abundance or diversity associated specifically with the T. cordata flowering phase. These findings indicate that T. cordata stands in protected areas harbor diverse insect assemblages typical of temperate deciduous and mixed forest habitats and include a broad spectrum of non-bees and other potential pollinators. Therefore, we did not detect a distinct peak in insect abundance or species richness during the T. cordata flowering period, indicating that flowering did not coincide with a pronounced maximum in pollinator-related insect activity. However, the quantitative patterns observed suggest that, in this context, T. cordata provides only modest support for pollinator guilds, and its role is better interpreted as one component of wider forest insect diversity rather than as a primary driver of pollination services. Full article

The two-spot cotton leafhopper (TSCL), Amrasca biguttula (Hemiptera: Cicadellidae), is an emerging invasive pest in the southeastern United States. Although TSCL has historically been associated with cotton and vegetable crops, recent detections on ornamental hibiscus have raised regulatory concern, including “Stop Sale and Hold” orders and an emergency quarantine in Texas. Despite increasing pressure on hibiscus, no insecticide efficacy data exist for ornamental systems. We evaluated the acute (0–24 h) and residual (24–96 h) toxicity of bifenthrin, flupyradifurone, and tolfenpyrad against adult and immature TSCL using a sequential-cohort leaf-disc bioassay. New insects were introduced at 24 h and 72 h to isolate residue-based mortality from prolonged exposure effects. Bifenthrin caused the highest acute mortality at 24 h, whereas flupyradifurone and tolfenpyrad exhibited slower initial activity but strong residual performance. Immatures were more susceptible than adults across all doses. By 72 h, all three insecticides produced near-complete mortality, with significant treatment and dose effects confirmed by ANOVA and binomial GLM analyses. Dose–response curves showed steep concentration-dependent mortality for bifenthrin and tolfenpyrad and a time-dependent response for flupyradifurone. These results provide the first insecticide efficacy data for TSCL on ornamental hibiscus and offer immediate guidance for nursery producers and regulatory agencies. The findings establish a foundation for whole-plant and greenhouse evaluations to support integrated management and interstate plant-movement compliance. Full article

The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the vector of the devastating citrus disease Huanglongbing, posing a significant threat to the global citrus industry and necessitating environmentally sound management strategies. This study aimed to evaluate Australian tea tree oil (TTO) and its primary constituents as potential botanical insecticides. Gas chromatography-mass spectrometry (GC-MS) was performed to analyze the chemical profile of commercial TTO, and behavioral effects on D. citri adults were assessed using a Y-tube olfactometer. Direct spray bioassays were conducted to determine contact toxicity. A total of 12 compounds were identified, with TTO being a Terpinen-4-ol chemotype, dominated by Terpinen-4-ol (40.62%), γ-Terpinene (21.46%), and α-Terpinene (10.45%). TTO demonstrated potent, concentration-dependent repellency, achieving 100% repellency at 10 g/L. In contrast, Terpinen-4-ol alone was attractive to psyllids at low concentrations, suggesting synergistic or masking effects within the complex oil blend. TTO and its major constituents also exhibited significant dose- and time-dependent contact toxicity. Although the 72 h LC₅₀ of TTO (19.18 g/L) indicates lower potency compared to conventional insecticides (0.59–1.23 g/L), its combined repellent and toxic properties make it a promising candidate for integrated pest management (IPM) programs aimed at controlling D. citri and mitigating insecticide resistance. Full article

The compatibility of insecticides with biological control agents is a critical component of integrated pest management (IPM). In this study, the lethal and sublethal effects of acrinactrin, chlorantraniliprole, flupyradifurone, pyriproxyfen, spinosad, and spiromesifen on the egg stage of Orius niger (Wollf) (Hemiptera: Anthocoridae) were evaluated under laboratory conditions. Egg hatchability, immature survival, reproductive performance, and population parameters were analyzed using the age-stage, two-sex life table. Egg hatchability was lowest in the acrinactrin treatment (51%) and highest in the pyriproxyfen treatment (93%). Nymphal survival varied from 0% to 80%, with acrinactrin causing complete mortality and a significant reduction in spinosad, while the highest nymphal survival and population growth was recorded in spiromesifen treatment. The intrinsic rate of increase (r, day⁻¹) was 0.00, 0.05, 0.05, 0.08, 0.004, and 0.06 for acrinactrin, chlorantraniliprole, flupyradifurone, pyriproxyfen, spinosad, and spiromesifen, respectively, while fecundity (F, eggs female⁻¹) values were 0, 15.20, 15.83, 42.32, 10.37, and 21.85, respectively. According to the International Organization for Biological Control (IOBC) classification, acrinactrin was harmful, spinosad moderately harmful, and the remaining insecticides slightly harmful to O. niger eggs. Pyriproxyfen and spiromesifen were the most compatible with IPM programs. Caution is warranted for chlorantraniliprole due to its effects on reproductive parameters, whereas spinosad and acrinactrin should be avoided on O. niger eggs. Full article

The predatory bug Arma custos (Hemiptera: Pentatomidae) is a natural enemy insect capable of preying on over 40 types of agricultural and forestry pests. Here, we describe the characteristics of the morphology and ultrastructure of its venom apparatus visualized using light and electron microscopy. Light microscopy revealed that the venom apparatus of A. custos consists of a pair of main gland and tubular accessory gland. The main gland consist of two lobes, the anterior main gland (AMG) and posterior main gland (PMG). Between the two lobes of the main gland, there is a strong constriction, characterizing a hilum (Hi) where two separate ducts, the venom duct of the main gland (VD) and the duct connecting the accessory gland to the main gland (AMD), are inserted. The VD extends toward the head and connects to the venom pump (VP), while the AMD extends toward the thorax and connects to the accessory gland (AG). Ultrastructural examination of the venom glands reveals that the AMG and PMG consist of a layer of cubic or spherical glandular cells forming a large circular lumen, while the AG exhibits two narrow lumens. The secretory cytoplasm of AMG, PMG, and AG contains a well-developed rough endoplasmic reticulum, along with mitochondria, nuclei, secretory vesicles, autophagosomes, and secretory granules. However, significant differences exist in the ultrastructural characteristics among the three glands. Unlike glandular secretory cells in the venom glands, the ultrastructure of VD, and AMD reveals only well-developed nuclei, mitochondria, and elaborate plasma membrane folds. These results indicate that venom proteins are synthesized and stored by the AMG, PMG, and AG, while the VD and AMD ducts are responsible for transporting the venom. Full article

Riptortus pedestris (Hemiptera, Alydidae) is widely distributed across East Asia, where significant genetic differentiation may occur among geographic populations. To understand the genetic structure, historical dynamics, and formation of geographic distribution patterns in China, we conducted a phylogeographic analysis using three mitochondrial genes (COI, COII, Cytb) from 35 populations. After PCR amplification, we performed genetic diversity analysis, Fst/Nm estimation, phylogenetic reconstruction (ML, BI, NJ), haplotype network, AMOVA, neutrality tests, mismatch distribution, and molecular dating. Results revealed high genetic diversity (Hd > 0.81, π > 0.011), an AT-rich base composition, and faster evolution at the first codon position. Genetic and geographic distances were significantly correlated, with high Fst values indicating strong differentiation, especially between southwestern/southern and other populations. Two main clades were identified: Clade 1 (mainly southern and southwestern China) and Clade 2 (central, northern, northwestern, and northeastern China). A star-like haplotype network and neutrality tests suggested a rapid expansion around 0.019–0.022 Ma (Last Glacial Maximum), and molecular dating estimated the main split at ~0.029 Ma. AMOVA and Gst/Nst confirmed significant phylogeographic structure with most variation among populations. This study provides initial evidence for the genetic differentiation and evolutionary history of R. pedestris in China, demonstrating that its population structure was shaped by climatic changes and geographical isolation, providing key insights into its adaptive evolution and dispersal. Full article

Psocids are difficult to manage using insecticides, hence the need for alternatives including biological control. Evaluation of data from two separate studies was conducted. One study investigated the potential of Cheyletus eruditus (Shrank) (Trombidiformes: Cheyletidae) and Cheyletus malaccensis Oudemans to manage Liposcelis decolor (Pearman) (Psocodea: Liposcelididae), whereas the other investigated the potential of Xylocoris flavipes (Reuter) (Hemiptera: Anthocoridae) to do the same. Temperature and relative humidity conditions were similar in both studies. However, the five predator–prey (P-P) ratios for the mites (0:20, 1:20, 2:20, 4:20 and 10:20) were different from those of X. flavipes (0:240, 1:240, 2:240, 3:240 and 5:240). The three predators demonstrated significant prey suppression; however, the level of control by X. flavipes was higher compared to the mites. At optimal prey conditions of 32 °C and 75% RH, all predators maintained high suppression. Temperature significantly influenced progeny production, with high reproduction observed at 20 and 24 °C for the Cheyletus spp. and at 28 and 32 °C for X. flavipes. Relative humidity of 63% was detrimental to Cheyletus spp. progeny production. While the results from this evaluation for the purpose of comparison should be interpreted cautiously, the different performances of the predators provide valuable insights for biological control of stored-product psocids. Full article

Parasitoids use different signals to locate their hosts, and these signals can modulate their behavioral decisions. Thus, patch selection and foraging in patches with different characteristics depend on their ability to gather and use such information efficiently. In this study, we evaluated whether the parasitoid Eretmocerus eremicus (Hymenoptera: Aphelinidae), a natural enemy of Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) on tomato plants (Solanum lycopersicum), uses scent cues to select and forage in patches that differ in host density and predation risk. Using choice bioassays in a wind tunnel under a continuous airflow, we recorded selection patch and selection time, as well as foraging parameters, including residence time, oviposition events, and attacks. Our results show that E. eremicus discriminated between sites with and without hosts using scent cues, but discrimination between patches with different host numbers was not detected under our assay conditions. It also distinguished between patches with maximum risk and those without risk, but not between subtle differences in risk. These findings suggest that E. eremicus, responded mainly to contrasting olfactory cues rather than to subtle odor differences. From an applied standpoint, our results motivate deeper investigation into how host- and predator-associated olfactory cues could fine-tune parasitoid deployment in biological control. Full article

Aphids are among the most significant agricultural pests worldwide. Artificial diets are a critical foundation for aphid physiological and biochemical research and the development of pest control technology. However, their phloem sap-feeding habits, extraoral digestion characteristics, and host specificities pose numerous challenges to the development of artificial diets for aphids, including population degradation, reduced fecundity during long-term rearing, and a lack of methodological diversity in dietary formulation research. In this review, we summarize the research on artificial diets for aphids, encompassing the history of artificial rearing, rearing methods, and nutritional composition analysis of these diets. Furthermore, we discuss the optimization of diet formulations based on aphid digestive enzymes and symbiotic bacteria. We aim to synthesize successful developments of artificial diets for aphids and extend their application to diverse aphid species. Future development of artificial aphid diets should focus on matching the types and contents of nutritional elements with the digestive enzymes and gut microbes of aphids. It is necessary to develop specific artificial diets for targeted aphid populations rather than merely adopting successful formulations and experience with Myzus persicae or Acyrthosiphon pisum. In addition, automated and large-scale aphid rearing devices should be developed, and further research on population degradation during long-term aphid rearing is required to explore multifaceted solutions involving nutritional and environmental aspects. Full article

This report contains the first molecular record of the two-spot cotton leafhopper, Amrasca biguttula (Ishida) (Hemiptera: Cicadellidae), in the United States. Nymphs of multiple instars and adult specimens were collected from a cotton (Gossypium hirsutum) field in Macon County, Alabama, in August 2025. While distinct paired dark spots were observed on the forewings of adult specimens, this trait was inconsistently present on nymphal wing pads. Cytochrome oxidase I (COI) DNA barcoding confirmed the specimen identity. The United States sequence shared > 99% identity with Asian A. biguttula references, and phylogenetic analysis placed it within the A. biguttula clade with 100% posterior probability support. Although this pest was previously reported in 2023 from Puerto Rico based solely on morphological traits, our findings provide the first DNA-confirmed evidence of its presence in the United States. Given its well-documented role in damaging cotton across Asia and Africa, this report underscores the urgent need for monitoring and development of management strategies in United States cotton-growing regions. Full article

The compound eye of the family Psyllidae (Hemiptera: Sternorrhyncha) remains one of the least studied among hemipteran insects. Among the approximately 4000 psyllid species worldwide, the pear psyllid Cacopsylla chinensis (Yang et Li) is a major pest of pear trees in China. The ultrastructure of the compound eye of adult C. chinensis was investigated using a transmission electron microscope (n = 12 adult). The eyes are of the apposition type, lacking a clear zone. Each ommatidium features a laminated corneal lens (about 16.9 ± 1.7 μm in diameter and 7.6 ± 1.7 μm in thickness), a eucone crystalline cone, a centrally fused rhabdom formed by eight retinula cells (R1–R8), and both primary and secondary pigment cells. The 57.0 ± 3.6 μm long rhabdom exhibits a two-tiered structure: a distal region comprising R1-R7 and a proximal region composed of R1-R6 and R8, with R7 withdrawing. Throughout this structure, the rhabdomeres of R1-R6 contribute continuously along the entire length, while R7 and R8 are restricted to the distal and proximal regions, respectively. The microvilli of the rhabdom are arranged in two orthogonal directions. Based on the similarity between the compound eye of C. chinensis and those of other diurnal hemipterans, the evolution and function of eyes are briefly discussed. Full article

Empoasca onukii severely damages tea plants as a major sap-sucking pest, leading to the increasing adoption of biopesticides as a sustainable alternative to chemical control. However, existing research has largely focused on the final lethal effects of these agents, while their short-term interference patterns on pest feeding behavior remain unclear. In this study, six biopesticides—azadirachtin, matrine, Beauveria bassiana, Metarhizium anisopliae CQMa421, Mamestra brassicae nucleopolyhedrovirus (MbNPV), and Bacillus thuringiensis (Bt)—were evaluated using the electrical penetration graph (EPG) technique to precisely analyze their interference on the short-term (6 h) feeding behavior of E. onukii, alongside field trials to validate control efficacy. EPG analysis revealed that different types of biopesticides significantly disrupted feeding in distinct ways. The two botanical pesticides and CQMa421 mainly prolonged the non-probing phase (waveform Np) and reduced active non-phloem feeding (C waveform) (p < 0.05); Bt and B. bassiana significantly extended the resting phase (waveform R) and decreased the frequency of passive phloem feeding (waveform E) (p < 0.05), whereas MbNPV exhibited a combined effect, simultaneously prolonging both Np and R waveforms while reducing waveform C (p < 0.05). Field trials showed that all tested treatments achieved complete control (100%) at 21 days post-application. Moreover, across a wide range of concentrations, they all demonstrated excellent and stable control performance. These findings provide diverse agent options for the green control of E. onukii in tea plantations and lay a foundation for constructing a green integrated pest management system centered on biological control for tea plant pests. Full article

The two-spot cotton leafhopper, Amrasca biguttula (Ishida) (Hemiptera: Cicadellidae), was recently detected in Florida and other southeastern states, USA. This is a quarantine pest of regulatory significance, since it can infest staple crops, such as okra, cotton, eggplant, and tropical hibiscus. While collecting infested okra plants in Homestead, Florida, five female Anagrus (Hymenoptera: Mymaridae) parasitoids emerged from eggs of Am. biguttula. The specimens were identified morphologically and molecularly by sequencing the cytochrome c oxidase subunit I (COI) gene and internal transcribed spacer 2 (ITS2) region of nuclear ribosomal RNA. Two Anagrus species were identified: Anagrus vulneratus and Anagrus sp. near vulneratus. These parasitoids are not known to occur in the Old World, the origin of Am. biguttula. Rather, they are native to North America. The available evidence suggests that the collected specimens switched from unknown local hosts in southern Florida to parasitize eggs of the invasive Am. biguttula. Future research to ascertain the identity of A. sp. near vulneratus and evaluate the efficiency of both parasitoids as natural enemies of Am. biguttula is warranted. Full article

The soybean aphid, Aphis glycines Matsumura, is an important pest in soybean, Glycine max (L.) Merrill. To investigate the adaptability of various A. glycines generations to high temperatures, this study assessed various life parameters of A. glycines exposed to a diurnal temperature of 33 °C and a nocturnal temperature of 20 °C (33 °C/20 °C) over three generations, compared to a diurnal temperature of 25 °C and a nocturnal temperature of 20 °C (25 °C/20 °C), by life table approach. The adult survival rates of A. glycines in the first (G₁), second (G₂), and third generations (G₃) at 33 °C/20 °C were found to be lower than those at 25 °C/20 °C. Additionally, exposure to 33 °C/20 °C reduced aphid total longevity, oviposition day, and fecundity for G₁, G₂, and G₃ compared to 25 °C/20 °C. These findings indicate that A. glycines can develop and reproduce at a diurnal temperature of 33 °C across the three tested generations, albeit with variations in certain life parameters compared to 25 °C. The results are important for understanding the adaptability of A. glycines to temperature fluctuations and for predicting the population dynamics of this pest in soybeans in Heilongjiang, China, which is currently experiencing rising environmental temperatures. Full article