天幕毛虫抱寄蝇的初步研究

天幕毛虫抱寄蝇是柞蚕放养场内大害虫——天幕毛虫(Malacosoma neustria testaceaMots.)的重要天敌。在辽宁省各蚕区普遍发生。据作者在复县调查,其寄生率为93.6％,在新金县调查,寄生率为86.3％,对天幕毛虫的发生发展具有很大的抑制作用,很有利用前途。 又据作者了解,辽南部分蚕民认为,天幕毛虫抱寄蝇与柞蚕饰腹寄蝇一样也是柞蚕的     

利用自然寄主玉米螟人工大量繁殖玉米螟厉寄蝇的研究

本文报道1983—1984年我国利用自然寄主亚洲玉米螟(Ostrinia furnacalis)幼虫人工大星繁殖玉米螟厉寄蝇(Lydella grisescens)的技术和方法。研究结果表明:在正常的玉米螟人工饲料配方中添加0.05克维生素E后,饲养和累代繁殖的供试玉米螟幼虫对提高寄蝇的生活和生殖力效果显著;温湿度、光照和风是影响寄蝇交尾的三因素,温度28～30℃,相对湿度70—80％,日光光照和微风吹拂为寄蝇交尾的适宜条件;掌握羽化1天以上的雄蝇与当天羽化的雌蝇这一有利时机,交尾率可达80—90％;受精雌蝇以5％稀蜂蜜液和牛奶喂饲后,寿命延长,胚胎发育良好;在温度25—30℃及相对湿度80—90％的条件下,子宫内的卵经9—11天全部成熟,采用人工剖腹取蛆,以蛆与寄主幼虫的密度比为3:1或4:1,使其充分接触的接蝇蛆方法,寄生率一般为80—90％,最高可达98％;根据同一寄主幼虫体内寄生1—4个蝇蛆的不同营养和发育情况,测定其蛹重,观察和比较成虫抱卵量、寿命和生殖力的强弱,证明1头玉米螟幼虫体内寄生1—2厉蝇蛆较为有利。 玉米螟厉寄蝇人工大量繁殖研究的成功,不仅有利于我国玉米螟防治工作,而且将为我国生防领域开辟出一条利用寄蝇的有效途径。     

THE EFFECT OF TEMPERATURE ON EGGS AND IMMATURE STAGES OF CULEX ANNULIROSTRIS SKUSE (DIPTERA: CULICIDAE)

Abstract
No immature stages of Culex annulirostris were found during field sampling in 1979–1980 when the average water temperature was < 17 °C; they reappeared when the average water temperature was 19 °C and reached the peak density (mean 107 immatures/cylinder) at 26.5 °C.
The effect of 6 temperatures (15–40°C) on egg hatching, development and survival of the immature stages of Cx annulirostris in the laboratory showed that at 15 and 40°C, eggs failed to hatch and larvae died in the first instars. The optimum temperatures for egg hatching and the survival of immature stages were 25 and 30°C. At these temperatures, 85 and 82% respectively of egg rafts hatched, the mean number of larvae per raft was 258 ± 9.8 and 260 ± 11.4 with immature survival of 83.5 and 79.0% respectively. Mean time to hatch at 20–35°C ranged from 1.2 d (35°C) to 2.9 d (20 °C). Developmental times from first instar to adult ranged from 7.1 d (35 °C) to 25.2 d (20 °C). The threshold for development of the immatures was 15.6 ± 2.5°C and the thermal constant was 142.9 ± 26.5 day—degrees (incubation temperatures 20–35°C). At less suitable temperatures of 20 and 35 °C, hatching (57.5 and 45%), number larvae per raft (mean 139.8 ± 9.8 and 102.6 ± 14.2) and survival were low.