Abstract: 【Aim】 To clarify the life cycle, overwintering habitats, occurrence regularity, host plant species and natural enemy species of the rice water weevil (Lissorhoptrus orvzophitus) in Guangdong province, South China, so as to provide scientific guidance for the prevention and control of this insect pest.【Methods】 We investigated the life cycle and overwintering habitats of L. orvzophitus in Guangdong through field surveys, cage observation experiments and ovary dissection from March, 2019 to April, 2021, identified its overwintering transitional host plants through molecular detection of the midgut contents in adults, and detected its main natural enemies using sequence characterized amplified region (SCAR) marker technology.【Results】 L. orvzophitus had two generations a year in the double cropping rice area of Guangdong province, and had overwintering and oversummering habits during March, 2019 and April, 2021. A complete generation of L. orvzophitus needed (140.86±1.05) d, and the larval duration was about 20 d in Guangdong. L. orvzophitus overwintered as adult in Guangdong province. The overwintering habitat pattern was paddy field, transitional zone (grassland), and swamp (abundant water grass). It was found that the ovary of L. orvzophitus adults during the overwintering period underwent diapause, and the ovarian grade was level Ⅰ. Through molecular detection of the midgut contents in L. orvzophitus adults, it was found that during the overwintering period, the main transitional host plants of L. orvzophitus were regenerated rice (Oryza sativa) and Leersia hexandra, and the main natural enemy was Pardosa laura, a nomadic spider, as revealed by the result of SCAR-based PCR.【Conclusion】 L. orvzophitus has two generations a year in Guangdong, and mainly overwinters in the swamp. The main transitional hosts during the overwintering period are Leersia hexandra and regenerated rice, and the main natural enemy in overwintering habits is P. laura. These findings have theoretical guiding significance for the accurate prevention and control of L. orvzophitus epidemic in Guangdong.

Key words: Lissorhoptrus oryzophilus, life cycle, overwintering, intestinal content, host plant