Abstract:

Latoia lepida is one of the main defoliators for the mangrove forest. The survey in the forest revealed that L.lepida principally distributed on the middle and upper parts of crown, the position soaked by seawater for short time gradually decreased from the internal beach to the external beach, the average injured percentage was 46.3% on the internal beach (high tide position), and the average injured percentage was only 13.8% on the external beach (middle tide position). The seawater soak-resistant experiment indicated that the influence of different soak times existed the extremely marked different on L.lepida survival rate, the population mortality rate increased with the increase of soaking time after soaking for more than 4 h, the population mortality reached the peak at the time of soaking for 8 h, and then the population survival rate stabilized to a certain level. The difference was not obvious among various-generation larval adversity resistance, the difference was evident among various-instars larval adversity resistance, the adversity resistance of larvae on seawater soaking was the main reason for the larval population distribution law and the large outbreak of L.lepida in the forest.

Key words: Latoia lepida, Adversity resistance, Mangrove forest