Abstract: 【Aim】 Beauveria bassiana can indirectly affect phytophagous insect pests by colonizing plants. This study aims to determine the responses of feeding preference and olfactory response of the neonate and 3rd instar larvae of Ostrinia furnacalis to symbionts of aerial conidia (AC) and blastospore (BS) B. bassiana-corn. 【Methods】 Each corn plant was inoculated with 20 mL B. bassiana spore suspension (1.0×10⁸ spore/mL), soil drench inoculation was used to establish the B. bassiana-corn symbionts, including the B. bassiana AC treatment group and the B. bassiana BS treatment group. The feeding selection rates by the neonate larvae and 3rd instar larvae of O. furnacalis to the corn leaves of the B. bassiana-corn symbionts of AC and BS treatment groups under the choice and non-choice conditions were tested by a dish leaf disc method. The olfactory selection coefficient and olfactory selection response rate of the neonate and 3rd instar larvae of O. furnacalis to the corn leaves of the B. bassiana-corn symbionts of AC and BS treatment groups were detected by Y-type olfactometer. 【Results】 The test results of the dish leaf disc method showed that the feeding selection rate of both the neonate and 3rd instar larvae of O. furnacalis to the corn leaves of the B. bassiana-corn symbionts of AC and BS treatment groups were lower than that of the control group under the choice and non-choice conditions. The neonate larvae of O. furnacalis had the lowest feeding selection rate to the corn leaves of the B. bassiana-corn symbionts of BS treatment group under the choice condition, while the neonate larvae of O. furnacalis had no significant difference in the feeding selection rate to the corn leaves of the B. bassiana-corn symbionts of AC and BS treatment groups under the non-choice condition. The results of Y-type olfactometer test showed that the olfactory selection response rate of both the neonate and 3rd instar larvae of O. furnacalis to the corn leaves of the B. bassiana-corn symbionts in AC and BS treatment groups (olfactory selection coefficient<0) were significantly lower than that in the control group (olfactory selection coefficient>0), suggesting that the two types of B. bassiana spore colonized corn leaves have negative chemotaxis to O. furnacalis larvae. 【Conclusion】 This study confirms that there is an obvious avoidance effect of the corn leaves colonized by aerial conidia and blastospores of B. bassiana on the feeding behavior and olfactory behavior of O. furnacalis, which could provide a theoretical basis to utilize the endophytic colonization of B. bassiana for ecological control of insect pests.

Key words: Ostrinia furnacalis, entomopathogenic fungi, plant endogeneity, behavioral response, leaf disc method, Y-type olfactometer