发菜类囊体膜色素蛋白复合物分离及其谱性质的研究

Nostoc flagelliforme Born. et Flah is highly adapted to drought stress, cold and light stresses, and suitable for growing in the unfavorable areas. This paper presents the results of the analysis of the membrane (mainly thylakoid membrane) lipids from N. flagelliforme in order to investigate the relationship between membrane lipid composition and stress resistance to this cyanobacteria. The membrane lipids are composed of monogalactosyl diacylglycerol (MGDG), digalactosyl diacylglycerol (DGDG), sulfoquinovosyl diacylglycerol (SQDG) and phosphatidylglycerol (PG). The major fatty acids in these lipids are palmitic (16∶0), palmitoleic (16∶1), stearic (18∶0), oleic (18∶1), linoleic (18∶2) and linolenic (18∶3) acids. In N. flagelliforme, polyunsaturated fatty acids account for 73% of the total fatty acids, much higher than that of the other cyanobacteria reported so far. Among which 16∶1 and 18∶3 are as high as 28.9% and 34.3% respectively. The high resistance of N. flagelliforme to abnormal conditions may be associated with the extent of unsaturation of fatty acids. In addition, the wild N. flagelliforme treated with water for 30 min and cultured for 24 h and the lipid and fatty acid composition were found to be not affected by water-absorption.     

Flight activity of three Spodoptera spp., Spodoptera litura, S. exigua and S. depravata, measured by flight actograph

Flight activities of three Spodoptera species were measured by the aid of flight actograph: S. litura and S. exuiga being regarded as long‐distance migratory insects, and S. depravata being non‐migratory and diapause‐inducible species. In all species tested, flight activities were observed only in scotophase, males showed far higher activities than females, being several times higher at the time of maximum flight activity, which was observed within 2 days after adult eclosion. Total flight activity in males was highest in S. litura, some being flyable even 12 days after eclosion, followed by S. exigua being one‐third compared to the former species, while in S. depravata flight activity was nearly half of that of the second species and most ceased to fly within a week after eclosion. There occurred species‐specific daily rhythms in flight activity during respective scotophase. In S. litura, both females and males exhibited a peak of flight activity shortly after light‐off and exhibited the second flight activity in late scotophase, the females slightly but the males more actively compared to early scotophase. In S. exigua, both sexes did not respond to light‐off, did not show a peak of flight activity in early scotophase, whereas males, but not females prominently increased activity toward the end of scotophase. In S. depravata, both sexes exhibited a peak of flight activity in early scotophase, and the males revived flight activity, being maximum shortly before light‐on, but the females did not show a clear rhythm in flight activity. These features observed in flight activity were discussed in relation with migratory capability.     

Effects of sublethal dose of chlorfluazuron on testicular development and spermatogenesis in the common cutworm, Spodoptera litura

This paper describes the physiological mechanism of action of chlorfluazuron on testicular development and spermatogenesis when sublethal doses (LD₁₀: 1.00 ng/larva or LD₃₀: 3.75 ng/larva) are applied topically to the cuticle of newly moulted fifth instars of the common cutworm Spodoptera litura (F.) (Lepidoptera, Noctuidae). These doses disrupt the growth and development of testes by decreasing the volume and weight of testes and thickness of testes sheath as compared with that of the controls. Sublethal doses of chlorfluazuron also significantly reduce the protein content of the testis, but do not affect the carbohydrate and lipid contents in newly emerged treated males when measured in μg/mg of testis as compared with that of the controls. Additionally, such doses disrupt spermatogenesis by reducing the number and size of eupyrene and apyrene sperm bundles in the testis. Very few or no eupyrene sperm bundles are observed in vas deferens of pre‐ and newly moulted adults compared with controls. This result shows that the transfer of sperm bundles from testes to vas deferens is delayed in treated males. The effects of chlorfluazuron on testicular development and spermatogenesis is thought to be one of the factors responsible for the reduction in fecundity, fertility and hatchability caused by sublethal doses of chlorfluazuron.     

Comparing the preferences of three herbivore species with resistance traits of 15 perennial dicots: the effects of phylogenetic constraints

Differences in palatability between 15 perennial dicotyledonous herbaceous plant species were investigated in a multiple choice test, involving three generalist herbivores. Palatability was compared with two categories of plant traits: defence characteristics and growth properties. On theoretical grounds, we expected a positive relationship between growth rate and palatability, and a negative relationship between palatability and defence traits. The possible effect of phylogeny on the outcome of the comparisons was investigated by analysing the data using phylogenetically independent contrasts. The three herbivores showed remarkably similar preferences, which indicates that the results of the choice experiment are a good representation of leaf palatability. The significant negative correlations found in a direct comparison between herbivore preference and relative growth rate, and between herbivore preference and lignin and dry matter content, did not hold after phylogenetic correction. On the other hand, one relationship emerged only when comparing phylogenetically independent contrasts: contrary to expectation, a negative relation was noted between juvenile growth rate and plant palatability. A possible explanation for the contradictory nature of this result is the uniformly ready availability of resources in our experiment.     

Further evidence for windborne movement of armyworm moths, Spodoptera exempta, in East Africa

Abstract. 1. Comparison of dominant wind directions with seasonal redistribution of Spodoptera exempta caterpillar outbreaks in East Africa provides further circumstantial evidence to support the hypothesis of downwind migration by adult moths.
2. Calculated backward and forward tracks for sixty-nine nights during the 1973–74 and 1974–75 seasons, when there were sudden increases in numbers of moths caught at six light traps, illustrate the variability of downwind movement due to the effects of temporary atmospheric disturbances.
3. Comparison of calculated tracks with known outbreaks before and after the nights of increased moth catch suggests that some outbreaks are derived from unreported sources, especially eariy in the season, and it is therefore unwise to link new outbreaks only with known earlier ones.     

Sub-lethal effects of SpltMNPV infection on developmental stages of Spodoptera litura (Lepidoptera: Noctuidae)

Application of different doses of SpltMNPV on final instars of Spodoptera litura showed dose-related mortality. A significant increase in the time for pupation and progeny mortality as well as reduced fecundity was observed in surviving larvae. Impact of sublethal doses on subsequent generation needs attention in designing baculovirus-based pest management.     

草地贪夜蛾成虫复眼明暗适应及黄光照射下明适应状态转化率

【目的】蛾类昆虫的趋光性与复眼明暗适应状态的转化有着直接的关系，本研究旨在阐明光照与草地贪夜蛾Spodotera frugiperda复眼明暗适应状态转化的关系。【方法】在光、暗适应条件和不同光照强度黄光照射下，在不同时间段，用相机迅速拍照，观察统计草地贪夜蛾成虫复眼的明暗适应状态及明、暗适应状态转化率。【结果】在明适应状态下，草地贪夜蛾成虫经黄光照射1 h后，随光照强度的增加，复眼明适应状态保持率逐步升高：雄成虫复眼在0.1~0.5 lx时明适应状态保持率为67.77%(有32.23%的转化为暗适应状态与中间状态)，4~6 lx时明适应状态保持率达到100%；雌成虫复眼在7~10 lx时，明适应状态保持率达98.90%。在明适应状态下，经黄光照射3 h后，草地贪夜蛾成虫复眼明适应状态保持率亦随着光照强度的增加逐步升高，在0.1~0.5 lx时雄成虫复眼明适应状态保持率为50.00%,雌成虫为32.23%；在光照强度7~10 lx时，雌雄成虫复眼明适应状态保持率分别为90.00%和100%。在暗适应状态下，草地贪夜蛾成虫经不同光照强度的黄光照射30 min后，成虫复眼向明适应状态逐渐转化：在0.1~0.5 lx光照强度时雌、雄成虫复眼明适应状态转化率均为93.33%；当光照强度达到0.6~0.9 lx时雌成虫复眼的明适应状态转化率达到100%，雄成虫复眼则在1~2 lx时达到100%。【结论】结果说明，草地贪夜蛾成虫有较强的光敏感性，且雌虫对黄光的光敏感性略强于雄虫。