土壤湿度对大豆食心虫幼虫越冬行为的影响

Effect of Soil Humidity on Overwintering Behavior of Soybean Pod Borer(Leguminivora glycinivorella) Larvae

为了明确土壤湿度对大豆食心虫（Leguminivora glycinivorella Matsumura）脱荚幼虫越冬行为的影响,在室内条件下,设置土壤湿度为0、7.5%、15.0%、22.5%、30.0%、37.5%6个不同梯度,利用圆盘等距随机排列等方法,测定了脱荚幼虫对不同土壤湿度的选择性以及脱荚幼虫在不同湿度土壤条件下入土爬寻时间、入土率、结茧历期和结茧率。结果表明：在土壤极端干燥（含水量0）或水淹（含水量37.5%）条件下,大豆食心虫脱荚幼虫不入土;土壤含水量7.5%~30.0%则均可正常入土,且随土壤湿度增大幼虫入土前爬寻时间缩短;在土壤含水量为15.0%时结茧历期最短;土壤湿度过高或过低均可显著影响大豆食心虫脱荚幼虫的入土率和结茧率。可见,土壤湿度对大豆食心虫幼虫越冬行为存在显著影响,土壤含水量15.0%左右是大豆食心虫脱荚幼虫入土越冬较适宜的土壤湿度。

The effect of soil humidity on overwintering behavior of soybean pod borer Leguminivora glycinivorella Matsumura（ SPB） was researched. Soil humidity was set to six different gradients： 0,7. 5%,15. 0%,22. 5%,30. 0% and 37. 5% under laboratory conditions. The overwintering behavior including the selectivity of SPB larvae to different soil humidities and the seeking and climbing time before drilling,rate of drill and cocoon in different soil humidities were measured using the method of random disk equidistant arrangement. The results showed that within the range of 7. 5% to 30. 0%,SPB larvae crawled into the soil. In addition,with the increase of soil humidity,the seeking and climbing time before drilling of full-grown larvae significantly shorted. However,the cocooning duration of full-grown larvae was the least at 15. 0%. But in the extreme dry soil（ 0） or flooded lower（ 37. 5%） conditions,SPB larvae did not crawled into the soil. Visibly,rate of drill and cocoon was significantly affected by soil humidity. In conclusion,15. 0% soil humidity was fit for SPB full-grown larva for overwintering.