Analysis of Population Dynamics and Migration Status of Ostrinia furnacalis Under Searchlight Trap and Ground Light-Trap

Ostrinia furnacalis is one of the most destructive migratory Lepidopteran pests, which seriously threatens the safety of maize production in China. The population dynamics and migration status monitored by ground light-trap and searchlight trap were compared and evaluated to provide a scientific basis for migration monitoring and early warning and control of O. furnacalis.

Ground light-trap and searchlight trap were used to monitor the population of O. furnacalis in Yantai, Shandong from 2019 to 2023. Daily collection and statistics were carried out on the number of O. furnacalis from April 1 to October 31 each year. The population dynamics of O. furnacalis were analyzed by drawing monitoring curves. The up-lighting pattern of O. furnacalis was analyzed based on the percentage of daily trapped number to annual trapped number by ground light-trap and searchlight trap. The migration status of O. furnacalis was analyzed based on the phenomenon of “sudden increase and decrease” of migration insect populations and the ratio of the number of insects trapped by searchlight trap and ground light-trap.

The number of O. furnacalis varied in different years and months, and the number trapped by searchlight trap was higher than that of ground light-trap. Pearson correlation analysis showed that there was no correlation between the annual total number of O. furnacalis trapped by ground light-trap and searchlight trap. The population dynamics of O. furnacalis monitored by ground light-trap and searchlight trap were basically consistent, but the peak of O. furnacalis trapped by searchlight trap was obvious, the start time was earlier than that by ground light-trap, and ended later. The up-lighting pattern of O. furnacalis was consistent between ground light-trap and searchlight trap, containing only three types: peak days, general occurrence days and non-occurrence days, and the peak day showed two peak stages with mid-July as the dividing point. O. furnacalis had two migration stages, with a low population and short duration from late May to late June, and a high population and long duration from late July to mid-September.

The population dynamics of O. furnacalis under ground light-trap and searchlight trap are consistent, indicating both methods are reliable for monitoring the dynamics of O. furnacalis. However, searchlight trap has more advantages in monitoring the early migration status of O. furnacalis because of its large number of insects, obvious peak of insects, early first peak appearance and long peak period. Searchlight trap can be used for timely monitoring the occurrence of O. furnacalis to prevent pest. The up-lighting pattern of O. furnacalis trapped by ground light-trap and searchlight trap is consistent with two peaks, so both traps can be used for monitoring. O. furnacalis migrates northward from late May to late June, and southward from late July to mid-September in Yantai. Therefore, monitoring and early warning and prevention can be strengthened in advance in the migration path to govern the migratory population of O. furnacalis.