温度对四川省甘孜州西藏飞蝗分布的影响

Influence of temperature on distribution of Locusta migratoria tibetensis Chen

温度是西藏飞蝗分布的主要限制性因子，作者通过试验测定了四川省甘孜州西藏飞蝗各种虫态的过冷却点、发育起点温度及有效积温。该虫初产卵的过冷却点为-24．4℃，孵化前为-20．7℃，是耐寒性最强的虫态，1～5龄蝻、雌、雄成虫过冷却点分别为-9．28、-8．51、-7．18、～6．64、-8．07、-7．86、-7．96℃。卵、1～5龄蝻、全世代的发育起点温度分别为14．17、15．84、16．64、16．80、16．35、15．00、14．61℃，有效积温分别为179．14、67．53、61．07、62．09、71．16、91．20、787．78日度，卵到蝗蝻的有效积温为540．2日度。统计气象资料表明，夏季高温不是西藏飞蝗限制因素，甘孜州石渠、色达、理塘的冬季低温影响西藏飞蝗的安全越冬，在甘孜州其他县可以越冬，并可发生1代。作者在乡城县观测圃饲养西藏飞蝗能成功越冬，年发生1代，其发育进度与有效积温分析一致。

Temperature is the major limiting factor for Locusta migratoria tibetensis development. The super-cooling points, developmental thresholds and effective accumulative temperatures of Locusta migratoria tibetensis at different developmental stages under constant temperature were measured in the laboratory. The super-cooling points of newly oviposited eggs, pre-hatching eggs, 1st -5th instar nymphs and female and male adults were -24.4 ℃, -20.7 ℃, -9.28 ℃,-8.51 ℃,-7.18 ℃,-6.64 ℃,-8.07 ℃,-7.86 ℃ and- 7. 96 ℃, respectively. It is clear that the egg was the stage of cold-hardiness. The developmental threshold temperatures of the eggs, 1st -5th instar nymphs and the whole generation were 14. 17 ℃ ,15.84 ℃ ,16.64 ℃ ,16.80 ℃ ,16.35 ℃ ,15.00 ℃ and 14.61 ℃, respectively. Their effective accumulative temperatures were 179. 14,67.53,61.07,62.09,71. 16,91.20 and 787.78 degreedays, respectively. The effective accumulative temperature from the egg stage to the nymph stage was 540.2 degreedays. The occurrence of L. migratoria tibetensis in Ganzi prefecture of Sichuan Province was analyzed. The statistic analyses based on local meteorological data indicated that the extreme temperature in summer was not the limiting factor to Locusta migratoria tibetensis, but the extreme temperature in Shiqu, Seda and Litang in winter was the limiting factor for its over-wintering. In most other areas, L. migratoria tibetensis could over-winter and finish 1- 2 generations based on the yearly effective accumulative temperature in Ganzi. Meanwhile, L. migratoria tibetensis could over-winter and finish one generation annually in garden near Xiangcheng City, with the same growth rate as expected by the model of effective accumulate temperature.