The number, shape and distribution of sensilla trichodea on the antennae of male silkworm moths Antheraea polyphemus and A. pernyi were observed and their quantitative difference was measured. The specificities of response to the components of sex pheromones of olfactory cells were investigated by single cell recording. The result indicated that there were1to 3 receptor cells in each olfactory sensillum on the antennae of male moths and they could be nominated as the AC₁-cell, AC₂-celland Alcell respectively. It was shown that each type of the receptor cells was highly specialized to one kind of the the components of the sex pheromones and there was certain difference in the response specific to the insect species.

Experiments were performed to study the incorporation of yolk protein labelled with FITC into housefly follicles in vitro. It was revealed that the rate of yolk protein incorporation depended on the concentration of yolk protein in the culture medium and temperature. The optimal condifion for yolk protein.lncorporation in this Grate's medium was 2 mg yolk protein per ml culture medium at 27℃ for twohours. The capacity of follicles in yolk protein uptake reached summit when housefly ovaries developed to the stage 6-8 about 48 hours after adult emergence.JH III, if added to the culture medium at oncentration of 5.9 to 117.3 ng/μl, could increase the amount of yolk protein incorporated into ovarian follicles. The yolk protein uptake by follicles in vitro was inhibited by ouabain, BSA or NAN₃.

Genetic studies were carried out on susceptible laboratory strains and field resistant strains of Rhyzopertha dominica and Sitophilus oryzae. Dose-mortality characteristics of susceptible and resistants parents and their F_l hybrids, F₂-backcross progeny and Fa mass cross progeny were assessed in order to determine inheritance character. Results indicated that the reaction of F₁ hybrid to phosphine was closer to its susceptible parent strain; x² analysis of the responses observed of F₁-backcross and F₂ progeny rejected the null hypothesis of monogenic inheritance for resistance. The inheritance of phosphine resistance in the two species was more complex and the resistance appears to be controlled by one or more autosomal factors but the major gene involved are incompletely recessive. Degrees of dominate (D) are-0.768 for R.Dorninica and-0.348 for S. aryzae.

An investigation was made on the aldrin epoxidationase activity and cytochrome P-450 level in the larvae of the diamond-back moth Plutella xylostella which were collected from different regions and distinguished as strains susceptible and resistant to DDVP and pyrethroids. The results of our further study indicated that there existed significant difference in quality and quantity of aldrin epoxidationase and cytochrome P-450 between the resistant and susceptible diamond-back moth larvae. The K _m,and V_max, values of aldrin epoxidationase from the resistant strain were 6.5 and 5.4 times higher when compared with that from the susceptible strain. Based on this finding, we presume that the difference of aldrin epoxidationase in quaility and quantity as well as the increase in cytochrome P-450 level are important factors for the development of insecticide resistance in the diamondback moth larvae and the qua litative difference in the enzyme systems may be more important.

Tests of the toxicity of several chitin synthesis inhibitors to the fourth instar larvae of diamondback moth, Plutella xylostella, were carried out in the laboratory. The results indicated that toxicities of XRD-473, CME-134, Cascade and IKI-7899were markedly higher than those of Dimilin and Alsystin, and toxicities of all these chitin synthesis inhibitors were significantly higher than those of the conventional insecticides DDVP, Cypermethrin and Dimehypo. Stomach poisoning was found to be the main mode of action, and contact poisoning was also important for IKI-7899 to the larvae. When adults were fed with the solutions of IKI-7899 or Cascade at 50 ppm, life spans of the female and male moths were shortened by 1 and 4 days respec- tively, number of eggs laid was only about 1/3 that of the untreated moth and the rates of egg hatching were reduced to 5.35% and 0, respectively. Temperature showed significant effect on the action of IKI-7899 in the speed of causing larval mortality, and the higher the temperature, the higher the mortality rate within the same period.

The influence of temperature on wing dimorphism in the virginoparae of Myzuspersicae and Lipaphis erysimi was examined by experiments under constant and natural temperature regimes supplemented by systematic sampling of field populations.The results demonstrate that low temperature promotes, while high temperature tends to suppress, the development of wings, and this promotive effect of low temperature is much stronger in M. persicae than that in L. erysimi. Observations with M. persicae on development stages sensitive to temperature showed that temperatures experienced by both the mothers and the young nymphs influence wing development, I.E., the control is both prenatal and postnatal. According to the results from this study and other relevant reports in the literature, we propose that temperature is animportant factor that should not be neglected in expounding the relationships between environmental factors and wing dimorphism in the aphid species studied.

The incidence of predation and parasitism on egg masses of the yellow stemborer Scirpophaga ineertulas (Walker) and related natural enemy populations were monitored under four rice planting densities (900000, 660000, 550000, and 160000 hills/ha) and growth stages (20,40,60 and 80 days after transplanting [DAT]) for two seasons. Egg predation was significantly higher at 20 and 40 DAT but not at the later stages although the predator populations increased as the planting density increased and season progressed. Conversely, egg parasitism declined as the plantingdensity increased and season progressed. At the higher planting density and later in the season parasitism declined along with number of species per egg mass. In general, egg mortality caused by predators and parasites declined significantly as the plantingdensity increased and the season progressed even though the enemy population increased. The significance of conservation and utilization of natural enemies of rice pests by manipulation of the planting density is discussed.

Through systematical investigation on the population dynamics and analysis of natural population life tables of the cotton bollworm Heliothis arrnigera in both corn and cotton fields in North China, it is concluded that corn fields could serve as themportant habitat of the third generation cotton bollworms and the mortality rate of immature cotton bollworms in corn fields exceeded that in cotton fields. Effect indices of the third generation cotton bollworms in cotton fields were manipulated and analyzed. Among the 7 variables the ratio of corn cultivation area to cotton cultivation area was found to be the active factor and the numbers of eggs laid by the second generation in the cotton fields was ascertained as the key /actor. These conclusions are tested with local data from 1973 to 1991 with satisfactory results.

In Kunming, Tomicus piniperda (L.) during the period of shoot feeding distributed mainly around the host trees in which the trunks had been used as the reproduction site. Around all these trees the population density decreased exponentially from the centre to the periphery. The diameter of dispersion area was about 30m.During shoot feeding, the beetle population dispersed into the new area around progressively. In the crown of host tree, the bark beetles distributed principally to 4th-10th whorls. The percentage of the bark beetles in the crown reached the largest in the 7th whorl. The rate of shoot damaged was the largest in the 6th—7thwhorls, followed in the second place in 2th-5th whorls, and decreased progressively from the 7th to the lowest whorl. At the levels in the crown, the bark beetles concentrated relatively in the outer portion of the crown, which was about the sum of the numbers in the middle and inner portions of the crown. In the early period of shoot feeding, the population distributed mainly in the outer portion of the crown, and then progressively dispersed to the middle and the inner portions of the crowns. In the late period of shoot feeding, most of population aggregated in the crowns of the trees which whould be attacked on the trunks, and distributedmainly in the outer portions of these crowns. On the basis of comprehensive analysis,the spatial distribution of the bark population in the crown is thought to be the result from the influence of the shoot diameter, the population density, tranferring damage, landing behavior, and sunlight on the bark beetle behavior.

Strepsiptera are very specialized insects which carry out a unique type of viviparity with egg formation and embryonic development taking place within haemocoel of the female. Elenchinus japonicus belongs to Elenchidae, Strepsiptera, and parasitizes the planthoppers Sogatella furcifera, Nilaparvata lugens and Laodelphax striatellus. In this work the stages of egg formation and embryonic development in S.Furcifera were carefully observed microscopically. The female insect lacks typicalovaries; the eggs develop and mature synchronically within the adipose tissue near the body wall. At the beginning, the primary oocytes are derived from the cystoblasts each of which consists of 256 sibling cells. One of these cells differentiates into the oocyte and the rest become the nurse cells. The mature egg is ellipticaland measures 75-100×40-50μm. It undergoes cleavage, blastoderm formation,segmentation of germ band, formation of appendages and dorsal enclosure to form the mature embryo monoembryonically.

This paper deals with the results of a comparative study on the male genitalia of 20 species of Meloidae from Xinjiang Uygur Automous Region. They may be summarized as follows: (1) The main components of the male genitalia are a phallobase and a median aedeagus, and the structures belong to the more variable, trilobatus type. (2) The morphlogical differences in genera, subgenera and species arenot only reflected in the characteristics of tergum IX and spiculum gastrale, which are associated with the genital musculature. (3) The characteristics of the male genitalia, like other external characters, can be used in identification and classification of the species.