关键词: 异色瓢虫, 高空诱虫灯, 地面测报灯, 种群动态, 迁飞状态

Abstract:

【Objective】The objective of this study is to clarify the population dynamics and migration patterns of Harmonia axyridis under light traps in Luohe City, Henan Province, analyze their changing trends, and to provide data support for the effective protection and utilization of H. axyridis for biological control. 【Method】From 2015 to 2024, systematic monitoring of H. axyridis was conducted in Luohe City, Henan Province, using searchlight traps and ground light traps. From March 1 to November 30 each year, the number of H. axyridis under the two types of traps was sorted and counted daily. Based on the annual and monthly trapping amounts, as well as the first and last capture dates under the two traps, the patterns and trends of H. axyridis phototaxis were analyzed. The population dynamics of H. axyridis were examined based on the daily trapping percentage relative to the annual total and the distribution of peak occurrence days across different seasons. Additionally, the migration patterns of H. axyridis were analyzed using the optimized ratio of trapping amounts between searchlight traps and ground light traps. 【Result】Over the 10-year period, the searchlight traps accumulated a total of 19 771 H. axyridis individuals, while the ground light traps accumulated 11 061 individuals. The number of insects caught by the searchlight traps showed a significant decreasing trend, whereas the number caught by the ground light traps showed a significant increasing trend. The annual catches of the two types of traps exhibited a significant negative correlation (P<0.05). Except for the years 2021-2023, when the ground light traps captured more individuals than the searchlight traps, the searchlight traps captured more individuals in all other years. H. axyridis was detected over a longer period under the searchlight traps, with the first occurrence date approximately 20 days earlier and the last occurrence date about 19.5 days later compared to the ground light traps. There were exceptionally high peak capture days under the searchlight traps, while no such phenomenon was observed under the ground light traps. Under the searchlight traps, H. axyridis exhibited three peak periods: late May to mid-June, mid- to late July, and late September to mid-October, with the highest capture occurring from late May to mid-June. The peak capture days for the ground light traps were concentrated from early June to mid-August, with no distinct peak periods, though the highest capture occurred from late July to mid-August. The air-to-ground ratio indicated three migration peaks for H. axyridis: late May to early June, early to mid-July, and mid-September to late October, with the highest migration intensity observed in October. Over the past decade, the southward migration of H. axyridis has significantly decreased, and the annual migration days have shown a significant declining trend (P<0.01). 【Conclusion】There are notable differences in the annual capture numbers and population dynamics of H. axyridis between searchlight traps and ground light traps. The peak periods under searchlight traps are more distinct and exhibit sharper increases and decreases. The earlier first occurrence and later last occurrence dates under searchlight traps make them more advantageous for monitoring H. axyridis migration. Influenced by global warming, the occurrence of H. axyridis in Luohe is increasing, while its migration is decreasing. The combined use of searchlight traps and ground light traps allows for a more precise analysis of migration behavior and quantification of migration intensity.

Key words: Harmonia axyridis, searchlight trap, ground light trap, population dynamics, migration status