黑侧沟姬蜂的生物学及种群消长规律研究

BIOLOGY AND POPULATION FLUCTUATION OF CASINARIA NIGRIPES GRAVENHORST

黑侧沟姬蜂(Casinaria nigripes Gravenhorst)是马尾松毛虫(Dendrolimus punctotus Walker)的主要寄生天敌,它主要寄生1—4龄松毛虫幼虫,其最高寄生率达66.64％。 黑侧沟姬蜂的全世代发育起点温度为9.0±0.6℃,有效积温446.9日度,在湖南浏阳县每年发生6—7代,以幼虫在松毛虫幼虫体内越冬。幼虫老熟时钻出寄主,爬至松针或松枝上结茧化蛹。在不同的生境中,该蜂对松毛虫的寄生率有明显差异,以在松阔混交林中寄生率最高,对各代松毛虫的年平均寄生率可达36.58％,而在植被稀少的疏残松林中寄生率最低,仅11.66％。其寄生率还随寄主世代不同而异,一般以对第3代松毛虫的寄生率最高,第1代次之,第2代最低。该蜂种群数量逐年波动与全年霜冻日数成负相关,与当年7、8月份降雨量和10月份平均气温成正相关。

Casinaria nigripes Gravenhorst is the primarily parasitoids of pine caterpillar, Dendrolimus punctams.They attack 1st to 4th instar larva resulting in,some times, the total parasitization up to 66.64%.Casinaria nigripes completes 6 - 7 generations a year with overwintering as larva in its hosts. The development threshold for whole generation is 9.0±0.6℃ with effective temperature summation to be 446.9 day-degrees. Mature larva emerges through host skin and pupates on some needdles and twins. Eight hosts and four Hyperparasites have been found in the field in Hunan province.Rates of parasitization in forests are influenced by types and growth codi-tion of forests with the highest in the mixed stand followed by the closed pure pine stand then the sparse stand.Parsitoid population sizes of Casiniria nigripes are related directly to the precipitations in July-Angust, and inversely to the numbers of frosty days in a year.