内蒙古荒漠草原亚洲小车蝗的种群动态

2010—2011年于内蒙古乌兰察布市四子王旗格根塔拉草原对亚洲小车蝗Oedaleus asiaticus(B.-Bienko)种群动态进行了研究。结果表明,亚洲小车蝗种群空间格局为随机分布;亚洲小车蝗于6月中旬开始孵化出土,1～3龄蝗蝻高峰期在6月中下旬至7月初,终见期在7月下旬;4～5龄蝗蝻于6月下旬始见,高峰期在7月上中旬,终见期在7月末;成虫于7月上旬始见,高峰期在7月中旬至8月下旬,终见期在9月上旬。应用最优分割法将亚洲小车蝗种群动态划分为3个阶段:(1)6月中旬,为蝗蝻开始出土期,数量稀少,空间格局为聚集分布或随机分布;(2)6月下旬至7月上中旬,为蝗蝻发生盛期,密度低时为随机分布,密度高时为聚集分布;(3)7月中下旬至9月上旬,为成虫发生期,空间格局为随机分布。

Population dynamics of Oedaleus asiaticus on desert grasslands in Inner Mongolia

The population dynamics of Oedaleus asiaticus （B.-Bienko） was investigated on the Gegentala grasslands of Siziwangqi county, Wulanchabu city, Inner Mongolia from 2010 to 2011. The spatial distribution of the grasshoppers was random. Nymphs began to occur in mid-June. The first to third instars peaked in density from mid to late June to early July and were gone by late July. The fourth to fifth instars began to appear in late June and peaked in early-mid July before disappearing at the end of July. The adults began to appear in early July, peaked in mid-July to late August, and disappeared in early September. The population dynamics of O. asiaticus was divided into three periods using the optimal dividing method： （ 1 ） Nymphs began to emerge in mid-June, population density is low and individuals are randomly dispersed or aggregated. （2） The nymphs occur mostly during late June and early-middle July and are either randomly dispersed at low density or aggregated at high density. （3） Adults occur from mid to late July to early September and are randomly distributed.