生态因子对赣南桉树枝瘿姬小蜂雄成虫比率的影响

桉树枝瘿姬小蜂Leptocybe invasa具有偏雌性的特点,了解桉树枝瘿姬小蜂的性比规律,有利于监测和掌控该蜂的种群动态,便于及时有效防控该蜂.2017年至2019年,采用在桉树Eucalyptus林中悬挂黄色粘虫板的方法,监测、观察桉树枝瘿姬小蜂成虫的发生动态,通过分析该蜂雄成虫比率及其影响因子,以弄清生态因子对该蜂雄成虫比率的影响.结果表明,赣南桉树枝瘿姬小蜂雄成虫平均比率为2.44％ ～34.05％,呈现季节波动性,在4-8月期间,雄成虫比率随时间推移逐渐上升,至7-8月时达到高峰,之后(9-11月)呈波浪式缓慢下降趋势.该蜂雄成虫比率与温度密切相关,在4-8月期间,雄成虫比率与月平均温度呈极显著正相关关系(r=0.87,P<0.01),而在9-11月期间,则随温度下降而缓慢下降;另外,由于2019年的夏秋温度比其它年份更高,导致2019年的雄成虫比率显著高于2017年和2018年.桉树品种也影响着该蜂性比,窿缘桉E.exserta上的该蜂雄成虫比率显著地高于DH201-2(E.grandis×E.tereticornis)和大叶桉E.robusta上的雄成虫比率(P<0.01).桉树枝瘿姬小蜂雄成虫比率与其种群动态存在一定关系,雄成虫比率与其成虫数量呈弱负相关关系.

Effect of ecological factors on male adult ratio of Leptocybe invasa in Southern Jiangxi Province

Leptocybe invasa has the characteristics of female preference. By mastering the sex ratio of the wasp, it is helpful to monitor and control the population dynamics, and control the wasp in time and effectively. Using the method of hanging yellow sticky board in Eucalyptus forest to monitor and observe the occurrence trends of adult wasps from 2017 to 2019. By analyzing the male adult ratio and its influencing factors, we could find out the influence of ecological factors on the male adult ratio of L. invasa . The results showed that the male adult ratio of L. invasa showed seasonal fluctuation, with an average ratio of 2.44%~34.05%. From April to August, the ratio of male adults gradually increased with time, and reached the peak from July to August. However, from September to November, the ratio of male adults decreased slowly in a wave pattern.The male adult ratio of the wasp was closely related to temperature. There was a significant positive correlation between male adult ratio and monthly average the temperature (r=0.87, P <0.01)from April to August, while it decreased slowly with the temperature drop from September to November. In addition, as the temperature in summer and autumn in 2019 was higher than that in other years, the male adult ratio in 2019 was significantly higher than that in 2017 and 2018. Eucalyptus varieties also affected the male adult ratio of the wasp, the male adult ratio on E. exserta was significantly higher than that on DH201-2 and E. robusta ( P<0. 01). There was a certain relationship between male adult ratio and population dynamics, and the male adult ratio had a weak negative correlation with the number of adults.