Molecular Entomology, 2025, Vol.16, No.1, 19-27 http://emtoscipublisher.com/index.php/me 20 However, agar increases feed costs and is prone to breeding bacteria. In recent years, studies have improved the formula of semi-artificial feeds without agar, such as replacing coagulants with corn stalk powder and soluble starch, which not only reduces costs but also is suitable for the growth and reproduction of corn borers, and realizes long-term succession rearing of corn borers (Chen et al., 2018). Countries such as the Philippines and Vietnam have also developed artificial feeds based on raw materials such as red beans and rice bran for large-scale rearing of Asian corn borers, which have been used in pest monitoring since 2009 (Rahayu and Trisyono, 2018). Compared with artificial feeds, direct feeding on host plants often achieves higher feeding rates and survival rates (Da Silva Ramos et al., 2022). This study was based on the rearing of Asian corn borer on corn ears under laboratory conditions, systematically observing its life history and biological characteristics, analyzing and evaluating the feeding behavior and Bt toxin sensitivity of larvae of different ages, and screening the insect age suitable for Bt toxin bioassay, providing a reference for the standardization of artificial rearing technology of Asian corn borer, standardization of Bt toxin bioassay methods and resistance monitoring. 2 Materials and Methods 2.1 Insect source acquisition The initial insect source of Asian corn borer was collected from the corn fields in Sanya City, Hainan Province. During the period from tasseling to grain filling, corn plants with borer symptoms were randomly selected in the field, and the corn husks were peeled to check for borers in the corn cobs and stalks. The corn borer larvae found were gently brushed into a clean glass bottle with a clean brush and collected. For individuals that had pupated at the base of the corn cob, the corn borer pupae were carefully removed with tweezers. The collected larvae and pupae were brought back to the laboratory breeding room for separate feeding and management (Figure 1). The field collection time was the autumn corn growing season, and the initial insect source included several larvae and dozens of pupae from multiple natural populations in the field to ensure genetic background diversity (Fang et al., 2021). Figure 1 Acquisition of Asian corn borer larvae from corn ears 2.2 Rearing equipment and feed 2.2.1 Rearing container Larvae were cultured in wide-mouth glass bottles (volume 500 mL) with gauze covers or transparent plastic boxes to ensure good ventilation and facilitate observation. Adults were reared in a 40 cm × 40 cm × 40 cm gauze cage with a corn seedling with heart leaves placed inside as an egg-laying substrate (Figure 2). 2.2.2 Feed source Larvae feed is young corn ears with husks (with milky kernels) freshly picked from the field. Select fresh corn ears that are not infected by borers, remove the outer husks and keep the tender husks and filaments. Provide sufficient fresh corn ears for larvae to feed on every day according to the number of larvae consumed, and replace corn ears that have finished feeding or become dry and deteriorated in time. For adults, prepare 10% honey water solution to soak cotton balls and place them in the cage for adults to feed (Figure 3).
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