Abstract The roots of cassava (Manihot esculenta Crantz) are an excellent source of dietary starch for millions of people and also serve as raw material for several industrial products. Cassava root production, however, is limited by insect, mite and disease pests. Tetranychid mites (Acari; Tetranychidae), until recently considered a minor pest of cassava, have assumed major pest status contributing up to 50 to 80% reduction in root yields, causing severe economic losses. Globally, numerous species of tetranychids have been reported causing damage to cassava. These include Tetranychus urticae Koch (syn = T. cinnabarinus [Poisd.]), T. truncatus Ehara, T. neocaledonicus André, T. kanzawai Kishida, Mononychellus tanajoa (Bondar) (syn = M. progresivus Doreste), M. caribbeanae McGregor, Oligonychus biharensis (Hirst), O. gossypii (Zacher), and Eutetranychus orientalis (Klein). Various studies have been undertaken and reported to explore methods (e.g., cultural methods, biological control, botanicals, host plant resistance, conventional chemical insecticides) to mitigate mite damage to cassava and manage their populations. This present work is a review of the pertinent scientific literature on the cassava mite complex, its economic impact, and potential management strategies for the pests.

The production of berries in Mexico predominantly focuses on the cultivation of blueberries (Vaccinium spp.), strawberries (Fragaria x ananassa Duch), raspberries (Rubus idaeus L.), and blackberries (Rubus ulmifolius Schott) (Servicio de Informacin Agroalimentaria y Pesquera [SIAP] 2022, https://nube.siap.gob.mx/gobmx_ publicaciones_siap/). The cultivation of these crops has experienced steady growth over the past 10 years, with annual increases ranging from 4.7% in blackberries to as much as 28% in blueberries (SIAP 2022). However, the increased production of these crops comes with an elevated risk of the emergence of previously unreported pests.

Abstract The sweetpotato whitefly, Bemisia tabaci (Gennadius) MEAM1 (Hemiptera: Aleyrodidae), continues to be a major pest of vegetable cultivation in Georgia, USA. Field-by-field surveying is an effective approach to determining the susceptibility status of a B. tabaci population to an insecticide. During 2020–2022, a modified maximum dose bioassay method was tested to characterize the insecticide response of B. tabaci field populations to several commonly used insecticides for whitefly management in Tift Co., GA, and the surrounding areas. A rapid bioassay was used for these evaluations that allowed for field assessments before spray applications to reduce the adult life stage of this species. The results of the evaluations were produced within 24-h following a 24-h root drench period. Our survey suggests that the neonicotinoids dinotefuran and flupyradifurone were the most effective insecticides from the Insecticide Resistance Action Committee (IRAC) group 4A. Cyantraniliprole was also effective, with 88 and 86% adult mortality following exposure to the high (maximum) and low doses, respectively. Conversely, the levels of control using another diamide, cyclaniliprole, were notably lower. Adding a low dose to the high dose provided an early indication of inefficient control with a product potentially indicating an increase in resistance. Specifically, a significant difference between the high and low doses suggests that the dose–response curve had shifted toward resistance development in each B. tabaci field population. The proposed bioassay method is meant for systemic insecticides that offer quick responses on adults. The use of this efficient method will improve evaluations prioritizing insecticides for use or rotation in an insecticide resistance management program.

Abstract Rice–crab cocropping refers to a new type of ecological aquaculture technology that involves raising crabs (Eriocheir sinensis H. Milne Edwards) in rice fields. To investigate whether crabs affect the community of spiders in the rice fields, we surveyed the species composition of spiders in two types of rice production fields—a rice–crab cocropping paddy and a conventional paddy—over two growing seasons. The fields were representative of the rice fields in Panjin City, Liaoning Province, China. We collected a total of 3,406 spiders representing 27 genera and 10 families over the duration of the study. The number of spiders in rice–crab cocropping paddy fields was significantly higher than in conventional paddy fields, but there was no significant difference in the types of spiders in the two types of paddy fields. An analysis of spider community diversity using Simpson's index, Shannon–Wiener diversity index, Pielou's index, and Margalef's index revealed no significant differences between the rice–crab cocropping paddy and the conventional paddy throughout the survey period. The evenness index and the richness index exhibited a positive relationship, whereas the dominance index showed a negative relationship. The dominant species in the two cropping systems was Pirata subpiraticus Boes. et Str. (Araneae, Lycosidae). Overall, we found no impact of cocropping with crabs on the composition and characteristics of the spider community.

Abstract Systena frontalis (F.) (Coleoptera: Chrysomelidae) is an insect pest of nursery production systems throughout the Midwest, Southeast, and Northeast regions of the United States. The original scientific name was Galleruca frontalis F. before reclassification of the genus to Systena. There is minimal information in the scientific literature providing evidence that S. frontalis is native or an introduced species. In addition, the overwintering life stage is unknown. However, records indicate that S. frontalis is native to North America based on reports of this beetle being found in 5 provinces of Canada and 31 states in the United States. Records also indicate that the adult may be the overwintering life stage. Current management strategies implemented to reduce feeding damage caused by S. frontalis adults to container-grown nursery plants are associated with foliar spray applications of contact insecticides. However, applying contact insecticides to plant material in nursery production systems is labor intensive and not cost efficient. Application of systemic insecticides to the growing medium is a management strategy that nursery producers can use to reduce feeding damage caused by S. frontalis adults. Research demonstrates that the systemic insecticides dinotefuran and thiamethoxam protect container-grown nursery plants 45 d after application. Therefore, based on empirical, scientific-based research, applying systemic insecticides before S. frontalis adults are active provides practical and cost-effective plant protection from adult feeding damage during the growing season, thereby allowing nursery producers to grow, market, and sell container-grown nursery plants.

Abstract Rosemary essential oil (EO), from Rosmarinus officinalis L. (Lamiales: Lamiaceae), has potent properties against stored insect pests. This study aimed to evaluate the efficacy of EOs from both manually extracted and commercially produced R. officinalis, as well as the main compound 1,8-cineole, against adults of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Chemical analysis of the R. officinalis EOs was conducted using a gas chromatograph–mass spectrometer. Toxicity and repellent effects were assessed through contact and fumigation bioassays in a factorial experimental design with five replicates. Each R. officinalis EO type showed nine major compounds (>90%), with 1,8-cineol as the predominant component (>52%). Contact toxicity bioassays showed 1,8-cineole had a median lethal concentration of 1.12% at 48 h, 1.54% for manually extracted EOs, and 1.64% for commercially produced R. officinalis EOs. Furthermore, 0.5% of 1,8-cineole displayed strong contact efficacy against T. castaneum. Fumigant toxicity was observed at 140.07, 127.28, and 121.52 μl/L air, respectively. Manually extracted EO at 160 μl/L air demonstrated strong fumigant efficacy against T. castaneum, acting as a contact (66–94%) and fumigant (82–69%) repellent within 8 h, outperforming commercially produced EO and 1,8-cineole. These findings highlight the potential of manually extracted EO from R. officinalis as a natural insecticide, effective in both contact and fumigation against T. castaneum. This offers a promising avenue for using plant extracts in storage pest prevention, potentially leading to the development of insecticide products.

Abstract Cassia fistula L., known as the golden rain tree, is a flowering tree that is native to Asia but is used as an ornamental plant in public and private gardens in many areas of Mexico. It is also important for its antifungal, antibacterial, antioxidant, phytochemical, and medicinal properties. In this study, floral visitors of C. fistula were identified in the urban area of Escarcega, Campeche, Mexico in three public gardens during the month of May using entomologic nets. The insects were preserved with 70% alcohol, transported to the laboratory, and identified to species level using taxonomic keys. In total, 124 insects were collected representing 8 species belonging to 7 genera. Of those insects collected, Trigona fulviventris Guérin-Méneville and Trigona silvestriana Vachal (Hymenoptera: Apidae) were the most abundant, accounting for almost 50% of the total specimens collected. Previous reports list 32 species of insects as floral visitors of C. fistula in Mexico. Our study adds six species to that list that had not been previously recorded: Epicharis elegans Smith, Eulaema polychroma (Mocsáry), Melipona sp., T. silvestriana, and Xylocopa latipes (Drury), which are all members of the family Apidae (order Hymenoptera), and Parachartergus apicalis (F.), a vespid (Hymenoptera: Vespidae).

Abstract Evidence is accumulating that insect epsilon class glutathione S-transferases (GSTs) play an important role in the resistance to xenobiotics such as insecticides. A Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) epsilon class GST gene, TcGSTe17, was previously found to be significantly induced following exposure to the plant derivative eucalyptol. However, whether TcGSTe17 is involved in resistance to eucalyptol remains unclear. In this study, TcGSTe17 was cloned from the T. castaneum. Development stage expression profiling revealed that TcGSTe17 was expressed at all development stages of T. castaneum but was highly expressed in late-stage larvae. Subsequent expression profiling of tissues showed that TcGSTe17 was highly expressed in the gut of larvae and the fat body of adults, and also revealed gender-specific expression patterns. In addition, the transcripts of TcGSTe17 were significantly increased following exposure to eucalyptol, and RNAi increased the susceptibility of the beetles to eucalyptol. Collectively, these results suggest that TcGSTe17 contributes to the susceptibility of T. castaneum to eucalyptol. These findings provide new data for the prevention of pest resistance.

Abstract The maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), is a major pest of stored grains that feeds on and develops inside the grain. The trehalose analog validamycin has a strong inhibitory effect on insect trehalase. Studies have found that validamycin affects several insects; however, no information is available on its inhibitory and physiological effects on these insects. In this study, validamycin’s inhibitory effect on trehalase was examined by incorporating it into artificial seeds and feeding them to S. zeamais. Trehalase activity was recorded throughout the developmental stages of the exposed weevils and was highest in the larval followed by adult, pupal, and egg stages. We found that feeding adult S. zeamais artificial seeds containing validamycin resulted in a significant reduction of trehalase activity in both males and females, although the primary source of trehalase was in the intestinal tract rather than in the reproductive organs. The validamycin treatment also had a concentration-dependent lethal effect, resulting in approximately 90% mortality, with females being more susceptible than males. In addition, the validamycin treatment caused a significant reduction in the number of first-generation progeny and S. zeamais demonstrated delayed development in a concentration-dependent manner. These data show that validamycin influences trehalase enzyme activity, reproductive success, and development of S. zeamais. The results obtained from this research will be valuable tools for designing a control strategy.

Abstract Based on transcriptome data of adults and pupae, 3 Minus-C OBPs (odorant binding proteins) genes were cloned and analyzed in various tissues (including head, thorax, abdomen, legs of female and male adults, and wings of males) of Apocheima cinerarius Erschoff (Lepidoptera: Geometridae). Expression patterns were examined across the developmental stages of egg, larva (1st–5th instars), pupa (non-diapause and diapause), and adults. The qRT-PCR results revealed a significant up-regulation of OBP8 in 3rd and 4th larval instars, with the highest expression level observed in 4th-instar larvae. OBP14 exhibited higher expression levels in diapausing pupal and adult stages, with highest levels in the female adult. Conversely, OBP18 displayed highest expression in the non-diapausing pupae, while exhibiting extremely low expression levels among other stages. The tissue expression profile revealed a gradual increase in the expression of OBP14, with highest levels in the male legs, whereas the expression pattern of OBP18 exhibited an inverse trend with maximum expression observed in the male head (including antennae). OBP8 exhibited high expression levels in the abdomen of the female adult, while OBP14 showed high expression in the legs of the male adult. Additionally, OBP18 displayed high expression in the female head. These findings suggest the crucial role played by OBP genes in both olfactory and non-olfactory tissues of A. cinerarius. The results provide a fundamental basis for further investigation into the recognition of odorant binding in A. cinerarius.