温度对草地螟成虫产卵和寿命的影响

EFFECTS OF TEMPERATURE ON OVIPOSITION AND LONGEVITY OF ADULT MEADOW MOTH (LOXOSTEGE STICTICAL1S L.)

在16℃、19℃、22℃、25℃、28℃、31℃和34℃的范围内,草地螟(Loxostege sticticalis L. )成虫的产卵前期与温度的关系呈逻辑斯谛曲线,产卵雌蛾数、产卵历期和产卵量均以22℃为最高。初步确定19—25℃为草地螟蛾产卵的适温范围,22℃为最适产卵温度,16℃和34℃分别为产卵温度的下限和上限。成虫寿命与温度的关系为负相关(r=-0.91,P<0.01)。表明在试验温度范围内,温度越高,成虫寿命越短。但温度对雌雄成虫寿命的影响不一致,在28℃以下的温度内,雄蛾寿命比雌蛾长:在31—34℃的范围内,雄蛾寿命比雌蛾短。根据以上研究结果,对我国草地螟发生为害区的种群动态规律进行了讨论。

Adults of the meadow moth, Loxostege sricticalis L., transferred directly after emergence to the constant temperature of 16℃?4℃ were monitored for preovipo sition period, oviposition rate and period, fecundity and longevity. The relationship between temperature and preoviposition period fell into a logistic curve. All females observed at 22℃ oviposited, but the number of ovipositing females decreased above this temperature. Oviposition period and fecundity at 22℃ were the longest and highest and significantly differed from those in other treatments except those at 19℃ and 25℃. According to the results obtained, 22℃ was considered as the optimum temperature for oviposition, and 16℃ and 34℃ as the lower and upper limits, respectively.Longevity of the adults was also affected by temperature. The longest longevity was at 16℃ (36.3 days) and shortest at 34℃ (8.6 days). The relationship between temperature and adult longevity was significantly and negatively correlated, regardless of males or females. However, males were more sensitive than females to the change of temperature by checking the correlation coefficients (for males r=-0.91, P<0.01 and females r=-0.76, P < 0.05). In addition, males lived longer than females at 16℃-28℃ and significantly differed at 16℃-22℃ (P < 0.05), but shor-ter than females at 31℃-34℃ and significantly differed at 34℃. Based on above results, patterns of population dynamics of the meadow moth in the major damage areas of China and principles of its forecast are discussed.