【摘要】 <正> 认识昆虫保幼激素对昆虫生长发育所起的调节作用已有较长时期,而探索用人工合成昆虫保幼激素类似物防治害虫还是近一、二十年的事。近年来,一些试验结果证明ZR-777等对蚜虫有很高的生理活性;Nassar(1973),Tamaki(1973),Benskin(1973),Kubr(1973)及广东农林学院(1976)等都有报道,但对不育类型,不育个体的不育程度与寿命,尤其是对胚胎发育影响,尚未见系统报道。本文比较系统地讨论这一问题。在室内和田间试验基础上,还初步提出该类化合物对蚜虫活性测定程序和鉴定指标。更多还原

【Abstract】 This is the second report on the effects of juvenoids on insects carried out jointly by the South-China Agricultural College and the Shantung College of Agriculture. The first report was published in Acta Entomologica Sinica 19 (3) : 263-81, 1976.1. Prom 1975-1977 we have tested 21 compounds of juvenoids against the cotton aphid. Among them, it was found that kinoprene (ZR-777) and a compound "SA-20" synthesized by the Shanghai Institute of Pesticides (trans, trans-11-chloro-3, 7,11- trimethyl 2, 4- dodecadienoic acid ethyl ester) were most effective against the cotton aphid. Their toxic effect to the aphid is about equal to that of Dimethoate. Preliminary field experiments showed that there is a possibility of the practical use of these juveniles for the control of the aphid.2. When the apterous or winged forme of the third to fourth instar nymphs of the cotton aphid were treated with a concentration of 0.087% or 0.029% of ZR-777, the population of the aphid slowly declined Among the survivors, a certain proportion could not develop to adults and became supernumerary nymphs or intermediate forms with low reproductive capacity. Some, however, develop to adults, but their life was shortened and the reproductive capacity was decreased. The winged supernumerary nymphs or intermediate forms could not fly, because their wings were degenerated; thus the migration in the field would be greatly reduced.When the apterous or winged adults were treated with the above concentrations of ZR-777, besides causing slow mortality and decreasing reproductive capacity, the majority of their progeny produced two days after treatment became supernumerary nymphs, thus giving rise to indirect sterility. The order of susceptibility to ZR-777 was determined to be 1st instar > 2nd instar > 3rd instar > apterous adult > winged adult > 4th instar apterous nymph > 4th instar winged nymph > fundatrigeniae on the primary host plant. After treatment with the juvenoid, intermediates between alate and apterous forms were also observed.3. It was found that ZR-777 interfered with the embryonic development of the aphid egg. With high doses (0.087%), at early stages, the embryonic development was inhibited, but at later stages, the development was accelerated. Lower doses right from the beginning accelerated the embryonic development. The acceleration on embryonic development does not mean that the reproductive capacity of the aphid could be increased, because the individuals died either during the embryonic stage or just before the 2nd instar. In fact, many fully-developed embryos found in the abdomen could not be deposited and the female finally died out. Thus the juvenilizing effect gave rise to indirect sterility.4. Juvenoids can produce sterility in the F1 progeny of the aphid. The effectiveness of sterility could be examined on the basis of the presence or absence of the genital plate or the degree of hardening of the plate. For the winged forms, the degree of the development of the wing pads may also serve as an index of sterility. Three different types of sterile individuals have been found by the authors: supernumerary nymphs, nymphal-adult intermediates and apterous-winged intermediates. The supernumerary nymphs have completely lost their power of reproduction and are usually short-lived.5. The evaluation of the effectiveness of Juvenoids is different from that of the conventional insecticides. It is not based on direct toxicity, but based on a complex of integrated physiological effects on the whole population. The evaluation of Juvenoids should be based on the decrease of the reproductive capacity of the population and the formation of sterile individuals in the present as well as in the succeeding generation (F1). For biological assay in the laboratory, we propose that preliminary experiments should be better if tests were carried out at first with the 1st- 2nd instar nymphs and then later with the winged 4th instar nymphs. It was found that the former is very susceptible, whereas the latter very resistant to the action of Juvenoids.6. Insect juv更多还原