The effectiveness of bio‐bait for managing Cnaphalocrocis medinalis (Guenée) in rice fields

BACKGROUND: Rice is one of the most important food crops for humanity and plays a crucial role in ensuring global food security. The rice leaf folder, Cnaphalocrocis medinalis (Guenée) presents a serious threat to rice production as a major migratory pest. With the increasing resistance to chemical pesticides, there is an urgent demand for innovative biological technologies in pest control. From 2020 to 2023, we evaluated the effectiveness of bio-bait against C. medinalis in Guangxi, Hunan and Jiangsu -key rice-producing regions in southern China. RESULT: The bio-bait showed a strong attraction to C. medinalis adults with high selectivity. Notably, 98.67% of the total insect adults trapped by the bio-bait were technically identified as C. medinalis, with a male-to-female ratio of 1.0552 ± 0.0070. The trapping efficiency of the bio-bait for male C. medinalis adults was significantly superior than that of sex pheromone lures, reaching a trapping amount that was 1.2073-fold greater. In the bio-bait treatment fields, the decline rate of moth catching of C. medinalis adults was 80.70%. And the decline rate of leaf-rolled plants (61.03 ± 2.16%) observed in the bio-bait fields was significantly higher than that recorded in fields treated with biotic pesticide (55.89 ± 2.10%). When compared to control groups, the bio-bait treatment and biotic pesticide treatment showed increases of average yield at 50.88 ± 6.48% and 43.04 ± 3.51%, respectively; correspondingly, this resulted in increases of average income at US$1737.07 ± 160.16 and 1587.83 ± 94.24 per ha. CONCLUSION: Applying the bio-bait can significantly reduce the population of C. medinalis adults, thereby enhancing rice yield. The efficacy of the bio-bait in both controlling the C. medinalis adult population and increasing yield is comparable to that of a biotic pesticide such as Bacillus thuringiensis. The bio-bait demonstrates substantial potential in the integrated pest management of C. medinalis in rice fields. © 2026 Society of Chemical Industry.