ABSTRACT Aster yellows phytoplasma (AYp) is a mollicute that infects numerous crops, including canola ( Brassica napus L.), in which it is pathogenic, and is transmitted by the aster leafhopper ( Macrosteles quadrilineatus Forbes). Understanding how AYp infection alters vector behavior and development is critical for predicting disease dynamics in agricultural systems. We used two‐choice and no‐choice bioassays to assess settling preferences and developmental performance of AYp‐infected and uninfected leafhoppers on AYp‐infected and uninfected B. napus . Arabidopsis thaliana L. was included as a reference host for developmental comparisons. At 2 weeks post‐infection, leafhoppers showed a significant preference for AYp‐infected plants; by 4 weeks, this preference disappeared. Uninfected leafhoppers produced significantly more nymphs on AYp‐uninfected plants than on AYp‐infected plants, although survival on B. napus was poor, and no individuals completed development. Phytoplasma titers in plants increased over time and corresponded with symptom severity. These results show that while AYp infection briefly influences vector settling behavior, B. napus is a marginal host that does not support full development, providing insight into vector–pathogen interactions and disease epidemiology in canola systems.

ABSTRACT Biopesticides based on entomopathogenic fungi are considered a potential alternative for controlling stink bug populations in soybean and maize crops. We investigated the susceptibility of immature stages of Euschistus heros (Fabricius, 1974) and Diceraeus melacanthus (Dallas, 1851) (Pentatomidae, Carpocorini) to infections by 30 strains of Beauveria bassiana and Metarhizium spp. In general, Metarhizium spp. strains exhibited a greater capacity to reduce egg hatching and infect nymphs of both E. heros and D. melacanthus compared to B. bassiana . Bioassays with two selected strains, one of each fungal species ( M . anisopliae CG1127 and B. bassiana CG1105), demonstrated a 10%–30% reduction in egg hatching compared to untreated eggs of both stink bugs, regardless of egg age (1, 2, or 3 days old). Second‐instar E. heros nymphs demonstrated higher susceptibility to M. anisopliae CG1127 infections than fourth‐instar nymphs, with ST 50 of 5.1 and 5.7, respectively. Furthermore, co‐infection assays showed that M . anisopliae CG1127 was more prevalent than B. bassiana CG1105, and no synergistic effect was observed against either E. heros or D. melacanthus nymphs. Adult survival of both E. heros and D. melacanthus after treatment with both strains consistently remained > 80%. Additionally, the number of eggs produced by E. heros females treated with fungal conidia did not differ significantly from the control. Our findings suggest that applications of selected fungal strains should primarily target the immature stages of both stink bug species to optimize biopesticide performance in field conditions.

ABSTRACT The boll weevil, Anthonomus grandis grandis Boh., presents significant management challenges due to its persistent presence and prolonged cropping season. One hypothesis posits that favorable factors, such as host availability and climatic suitability, contribute to the ongoing reproductive populations throughout the agricultural year. This research assessed the reproductive status of weevils during both the cotton‐growing and off‐seasons, with a focus on adult populations and the reproductive condition of females. Monitoring occurred over two agricultural years in commercial fields. We performed weekly recordings, identifying weevils based on sex and evaluating the reproductive status of females, particularly concerning mating status, sperm viability, and egg development. A total of 94 180 weevils were collected, and the average weekly capture per trap during the cropping season was comparable to that of the off‐season. The percentage of females collected during the growing season was approximately 20% higher than that in the off‐season; however, the percentage of copulated females collected off‐season exceeded that of females collected during the growing season in both years. The spermatozoa in these females demonstrated comparable viability across both periods, with values ranging from 72.6% to 95.9% annually. The presence of different stages of egg development in the reproductive system suggests that females could be engaged in oviposition activities during both the growing and off‐season periods. The findings suggest that a substantial percentage of females continue to be active during the off‐season in the Cerrado from the last generation growing season or emerging in the off‐season from spontaneous cotton plants. The findings indicate that females detect cotton plants for oviposition during this timeframe. Contrary to expectations, the fallow period does not significantly affect the suppression of the weevil population.

ABSTRACT Insects are emerging as valuable biomedical agents due to their unique biological properties, offering novel approaches for pathogen detection, drug development, and wound management. This review examines recent advancements in insect‐based medical applications, particularly in the context of antimicrobial resistance (AMR). A comprehensive analysis of studies on insect‐derived bioactive compounds, insect biosensors, larval therapy, and insect microbiota was conducted to evaluate their efficacy and clinical potential. Findings indicate that insect‐based biosensors, leveraging insect olfactory systems, enable non‐invasive detection of diseases, such as cancer and tuberculosis. Bioactive compounds, including melittin and anophelin, demonstrate potent antimicrobial activity, presenting promising alternatives to conventional antibiotics. Maggot debridement therapy effectively promotes chronic wound healing, whereas insect microbiota offers new antimicrobial agents to combat resistant pathogens. Despite these advancements, challenges related to standardization, scalability, and patient acceptance remain. Future research should focus on genetic engineering, optimized drug delivery systems, and regulatory frameworks to facilitate clinical translation. Insect‐based medical applications represent a promising frontier in biomedicine, necessitating interdisciplinary collaboration for their successful integration into healthcare.

ABSTRACT Paranthrene diaphana Dalla Torre and Strand (Lepidoptera: Sesiidae) is a diurnal clearwing moth that has become a notable pest in various regions of Iran, particularly in Tehran. This species poses significant threats to trees in Salicaceae , including weeping willow, Salix babylonica L., and the genus poplar, Populus . This study investigates the behaviors of P. diaphana , specifically its attraction to phenylacetaldehyde, acetic acid, and inflorescence essential oils of Rosa damascena Mill ( Rosaceae ). The assessment was conducted using a wind tunnel and a Y‐glass tube olfactometer to observe the insect's reactions. Additionally, the attraction of P. diaphana to flowers of R. damascena was evaluated in controlled cage experiments. Essential oil compounds from R. damascena were also identified during this research. The findings revealed that both virgin and mated females, as well as virgin males, exhibited attraction to the essential oils of R. damascena and phenylacetaldehyde. Notably, mated individuals were significantly more drawn to these substances compared with virgin ones. Furthermore, the attraction to R. damascena essential oils and phenylacetaldehyde was notably enhanced under light conditions. Compounds identified within the essential oils of R. damascena include phenylethyl alcohol (a precursor of phenylacetaldehyde), beta‐citronellol, benzene, 1,2‐dimethoxy‐4‐(2‐propenyl), hexadecanoic acid, 6‐octadecenoic acid, 9,12‐octadecadienoic acid (Z, Z), 8‐octadecenoic acid, and 1,2‐benzenedicarboxylic acid. The presence of phenylacetaldehyde is likely a significant factor contributing to the attraction of P. diaphana to R. damascena essential oils. Lastly, further research is warranted to explore the potential of using phenylacetaldehyde and R. damascena as bait and trap plants for monitoring and managing the population of P. diaphana in field conditions.

ABSTRACT Plant‐infesting insects require specific environmental conditions to ensure successful development and survival. Rhagoletis suavis (Loew) (Diptera: Tephritidae) develops within and around their walnut host as larvae and pupae, despite the allelopathic qualities of juglone in walnut fruit. We investigated whether components of the walnut fruit affected fly survival by subjecting larvae to four developmental substrate treatments: vermiculite and water, vermiculite combined with ground dry walnut husk and water, vermiculite and walnut husk‐soaked water, and vermiculite combined with ground dry walnut husk plus walnut husk‐soaked water. We measured survival across three life stage transitions: from larval emergence to pupation, from pupation to post‐overwintering, and from post‐overwintering to adult eclosion. We showed that the use of ground walnut husk with water in the substrate environment yielded a higher rate of survival compared with control conditions. We also found that ground dry walnut husk had higher moisture retention and a lower pH, which may aid survival compared with the other substrate conditions that contained walnut. The results of this study give insight into our understanding of how the environmental conditions experienced by plant‐infesting insects during development, including host plant chemicals, moisture, and pH, can affect survival.

ABSTRACT Various mechanisms have been proposed to play a role in host selection by bark beetles. Monoterpenes released by conifer trees may constitute a common attractive habitat cue for coniferous bark beetles, whereas monoterpenes are the principal components of tree resin and are toxic to bark beetles colonizing trees. Therefore, bark beetles infesting stressed and/or dead trees may avoid materials containing high amounts of host volatile compounds, such as host tree essential oils. Bark beetles also exhibit preferences for trunk diameters of host trees. Additionally, some bark beetles create species‐specific shaped galleries, requiring certain lengths of host materials. However, although host selection linked to trunk diameter (horizontal width) is well documented, there is limited understanding of whether bark beetles recognize vertical length of host materials. We conducted field experiments in Hokkaido, Japan, and determined the effects of host essential oils, and log length on host selection by Polygraphus proximus Blandford (Coleoptera: Scolytinae), which prefers trees with small trunk diameter, and creates horizontal egg laying galleries and vertical larval galleries. Host essential oil significantly reduced P. proximus attack density, and the attack density did not differ significantly among logs of various lengths (10 cm–80 cm) of A. sachalinensis (Fr. Schmidt) Masters (Pinaceae). Our study suggests that essential oils of a host tree can perform as repellents against conifer‐infesting bark beetles, and can be useful to reduce P. proximus attacks as a pest control strategy. Our study also suggests that P. proximus does not use vertical log length as a primary cue for host selection and may attack even on the shorter logs, which are insufficient for larval development and uncommon in natural settings.