南方小花蝽液体人工饲料的饲养效果评价

为评价一种液体人工饲料的饲养效果,以棉蚜饲养南方小花蝽作对照,用液体人工饲料连续两代饲养南方小花蝽若虫和成虫,对南方小花蝽各生长阶段的生长和发育指标进行调查。结果显示:用人工饲料饲养的南方小花蝽若虫历期(22～23天)与对照组(21天)之间不存在显著差异,说明液体人工饲料可以很好的满足南方小花蝽若虫生长的营养要求。然而,用棉蚜饲养的对照组南方小花蝽成虫获得率可达到63%,而人工饲料组连续两代的成虫获得率分别仅为45%和43%。取食人工饲料的南方小花蝽成虫,在产卵前期、产卵量及寿命方面与对照组都没有显著差异,仅在产卵期方面有着显著差异,人工饲料组小花蝽的产卵期为13～16天,而对照组小花蝽的产卵期可达20天,说明液体人工饲料也可以很好的满足南方小花蝽成虫生殖发育的营养要求。

南方小花蝽对寄主植物的产卵选择性及其卵的保存条件

室内研究南方小花蝽Orius similis Zheng在9种产卵寄主植物（辣椒，豇豆，长寿花，迎春花，黄荆，绿豆芽，棉花，石莲花，太阳花）的嫩茎上的产卵量、孵化率及繁殖系数。结果表明，南方小花蝽对不同产卵植物具有显著的选择差异性。从产卵量看，对辣椒嫩枝选择性最强，其产卵量占总产卵量的23．4％；从孵化率看，产在迎春花嫩茎上的卵的孵化率最高；从繁殖系数看，辣椒嫩枝和迎春花嫩茎作为产卵植物的繁殖系数较高，分别为7．6和12．8；从辣椒嫩枝和迎春嫩茎上的繁殖系数的构成看，两者明显属于2种不同的类型，前者属于高着卵量、低存活率类型，后者属于低着卵量、高存活率类型。对南方小花蝽不同虫态进行了抗寒能力的测定，结果表明南方小花蝽卵的抗寒能力最强，成虫次之，1—2龄若虫最弱。在此基础上做了卵的低温保藏实验，结果表明要保证80％以上的孵化率，最佳保藏条件为8℃下保藏9天。

桉树精油及其活性物质对干鱼害虫白腹皮蠹的熏蒸毒性(英文)

为了评估桉树精油和α--蒎烯对白腹皮蠹Dermestes maculatus Degeer的杀虫作用,采用生测方法测定了不同剂量和不同处理时间下,其幼虫和成虫的死亡率。结果表明:用桉树精油及其活性成分α-蒎烯处理白腹皮蠹成虫和幼虫后,可显著影响其死亡率(P<0.001)。白腹皮蠹的反应因化学物种类、剂量和暴露时间不同而异。当剂量为32μL/cm3的桉树精油处理白腹皮蠹幼虫72h后,死亡率可超过90%。同样的剂量对其成虫熏蒸72h后也表现高毒。在相同的剂量和相同的暴露时间下,α-蒎烯对白腹皮蠹的成虫和幼虫也表现高毒,且成虫的抗性比幼虫强。Probit检验结果表明桉树精油比α-蒎烯更有效。以上结果说明这些天然产物对白腹皮蠹种群的控制是很有用的。

Feeding mediated web-building plasticity in a cobweb spider

Behavioral plasticity has been proposed as a means by which animals alter their phenotypes in response to changing conditions.Animals may display behavioral plasticity as a consequence of environmental variation.The detritus-based,bell-shaped cobweb spider Campanicola campanulata is an ideal model to study behavioral plasticity,because its web architecture is easy to be quantified,and the functions of different parts of the web are clear.Though the plasticity of cobweb architecture has been reported in a few species,retreats as impor-tant defensive structures have rarely been considered before because retreats in most cobwebs are relatively small compared with the web size.We studied the web-building behaviors of C.campanulata under different feeding regimes.We set up 3 spider treatments with different feeding conditions:marginally well fed,moderately well fed,and extremely well fed,and observed the differences in the web architecture among them.In addition,we measured the mechanical properties of anchor silk,and also calculated the foraging and defense investment of the spiders.The results showed that marginally well-fed spiders build cobwebs with significantly longer length of anchor silk,lower retreat to the ground,more number and longer gumfooted lines,and larger capture area,while extremely well-fed spiders build cobwebs with significantly bigger retreat volume and higher height of retreat to the ground.In addition,marginally well-fed spiders invest significantly less during cobweb construction.However,there was no significant difference between the breaking force and elongation at break in anchor silk among different treatments.These results demonstrated that marginally well-fed spiders invest more in foraging,and extremely well-fed spiders invest more in defense,and the spider made a balance between foraging and predator avoidance in response to changes in physiological state.Our study strengthens the current understanding of web construction in cobweb spiders,especially those facing high costs during retreat construction.

夫妻之间的算计,雄性蜘蛛如何应对雌蛛的性相残?

大多数动物忙碌一生,终极目的都是为了繁衍后代,将自己的基因遗传下去.因此,为了获得最大的生殖利益,绝大多数非社会型动物都会挑选比较优秀的异性完成繁殖,这样产生的后代在数量和质量上可能会占优势,这就是达尔文提出的动物性选择理论.

Male opportunistic mating increases with intensity of female sexual cannibalism in 3 web-building spiders

Sexual conflict is common in animals,and female sexual cannibalism represents an extreme form of sexual conflict.Males in many species have evolved a variety of strategies to circumvent or decrease the risk of female sexual cannibalism.Opportunistic mating,by which a male mates with a female when she is disturbed or when she is feeding or undertaking moulting,is one of such kinds of strategies,and widely occurs in many animals,especially in spiders.However,whether the occurrence of male opportunistic mating depends on the intensity of female sexual cannibalism remains largely unexplored.We predicted a positive correlation between them.In this study,we tested this prediction by performing a series of mating trials in the laboratory using 3 species of web-building spiders with different intensities of female sexual cannibalism:Nephila pilipes,Nephilengys malabarensis,and Parasteatoda tepidariorum.We found that the occurrence of male opportunistic mating was positively,though not statistically significantly,correlated with the intensity of female sexual cannibalism,thus supporting our hypothesis.All together,we provide evidence that male opportunistic mating may have evolved to respond to the selection pressure posed by female sexual cannibalism.