纵卷叶螟绒茧蜂在不同类型田的发生规律

Occurrence regularity of Apanteles cypris in different paddy fields

为掌握纵卷叶螟绒茧蜂的发生特点,对纵卷叶螟绒茧蜂在单作稻田和水稻-玉米邻作类型田的发生规律进行了调查。结果显示:水稻-玉米模式中纵卷叶螟绒茧蜂的数量在玉米的扬花期明显高于单作稻田,最高值为单作稻田模式的3.36倍,但是田间纵卷叶螟绒茧蜂的寄生率并不高于单作稻田模式。在单作稻田未施药系统田,纵卷叶螟绒茧蜂的数量显著高于施药系统田;并且与稻纵卷叶螟幼虫的数量密切相关。不论在何种种植模式下,纵卷叶螟绒茧蜂的雌性比一直处于低水平,在单作稻田下,雌性比为0.2～0.3,在水稻-玉米邻作田,其雌性比为0.25左右。

Occurrence regularity of Apanteles cypris was surveyed in different paddy plant fields. The maximum number of A. cypris in the rice paddy neighboring to corn field was 3.36 times than that in the monocultural paddy field, and the peak was in corn＇s flowering stage. The parasitism rate of A. cypris in the paddy filed neighboring to corn was not higher than that in monocultural paddy field. In the field of monocultural paddy field, the number of A. cypris in non-spraying paddy field was significantly higher than that in spraying pesticide paddy field, and it is relative to the number of the Cnaphalocrocis medinalis larva. The number of A. cypris and the larva of C. me- dinalis dropped rapidly after the pesticides were sprayed. The female sex ratio of A. cypris kept low in the two paddy habitat, the female sex ratio in monocultural paddy field was 0.20 to 0.30, about 0.25 in the paddy neigh- boring to corn field.