Abstract:

To provide a basis for quarantine and control of Lissorkoptrus oryzophilus in Leshan rice area, the population dynamics and occurrence regularity were studied by a field investigation, and the correlation between the damage degree of adults and the number of larvae was analyzed by linear regression. The results showed that L. oryzophilus had one generation a year in Leshan. The migration period of overwintering adults to rice field was not consistent, and its spawning period was long. The larva development, pupation and eclosion period were very irregular, and the cross phenomenon of each insect state was obvious. The overwintering adults of L. oryzophilus were mainly distributed in 0-5 cm shallow soil of slopes and shade within 10 m from the rice field, and the amount of overwintering adults under the shade were the largest. In early spring, the average temperature was over 12℃, and the overwintering adults gradually recovered and fed on surrounding host plants. The survey showed that the epidemic regions covered 5 counties, 73 towns in Leshan, and the infested area was more than 8 thousand hm².

Key words: Leshan rice area, Lissorkoptrus oryzophilus, population dynamics, occurrence regularity