秦巴山区巨缘蝽亚科三种昆虫同工酶的初步研究(半翅目:缘蝽科)

为对缘蝽科分类提供生物化学和遗传数据,本研究运用聚丙烯酰胺垂直板电泳技术对巨缘蝽亚科三个种的酯酶同工酶进行了检测。结果表明:斑背安缘蝽Anoplocnemis binotataDistant不同组织酯酶酶谱不同,可能与适应特殊生理功能相关。斑背安缘蝽与波赫缘蝽Ochrochira potaniniKiritshenko、月肩奇缘蝽Derepteryx lu-nate(Distant)之间明显的遗传差异说明系统发育关系较远。三种缘蝽酯酶同工酶具有遗传多态现象,控制酯酶的基因位点均为5个,而且酯酶均为单体酶。     

The Effect of Logging on the Ground-Foraging Ant Community in Eastern Amazonia

In order to determine the suitability of ants as indicator organisms for habitat disruption in tropical forests, we studied the effects of both high and low impact logging on ant communities in northeastern Pará State, in the Brazilian Amazon. We collected ants from logged forests and unlogged forest sites with Winkler bags throughout the 1998 rainy season (January and April) and the following dry season (July and September). Both methods of timber harvesting showed impacts on ant community composition when compared with unlogged forest, although these impacts did not include modifications in total species richness or the relative contribution of each ant subfamily to the total number of species. Instead, logging induced alterations took place at the level of species and genera. A 2-fold reduction in the dominance of ants of the highly diverse genus Pheidole was associated with forest alterations in high-impact logging sites. Thus, logging in Amazonia can be seen to promote species shifts in ant communities, without, however, altering species richness. Ants of the genus Pheidole are potentially useful indicators for forest disturbances resulting from timber extraction.     

Pod hairs as a factor in Vigna vexillata resistance to the pod-sucking bug, Clavigralla tomentosicollis

Two varieties of Vigna vexillata Benth proved more highly resistant, both under field (free-choice) and screenhouse (no-choice) conditions, to infestation and damage by the pod-sucking bug Clavigralla tomentosicollis (Stål.) (Hemiptera: Coreidae) than cowpea (Vigna unguiculata Walp.) varieties. Trichomes on the pod of V. vexillata partly accounted for the resistance. However, other factors in the pod or seeds are involved in the resistance. Because the pod wall of V. vexillata is not tougher than that of cowpeas, biochemical characteristics of pods and seeds of V. vexillata will be further investigated.

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Résumé Deux variétés de Vigna vexillata se sont avérées plus résistantes aux infestations et dégâts causés par la punaise des cosses Clavigralla tomentosicollis (Stål.) (Hemiptera: Coreidae) que les variétés de Vigna unguiculata, tant en champ (condition de libre choix) qu'en serre (sans choix possible). Les trichomes des cosses de V. vexillata sont en partie responsables de cette résistance. Cependant d'autres facteurs de la cosses ou des fèves sont impliqués dan la résistance. Comme la paroi de la cosse de V. vexillata n'offre pas plus de résistance mécanique que celle de V. unguiculata, les études futures se porteront sur les caractéristiques biochimiques des cosses et des fèves de V. vexillata.

     

Leaf‐footed bugs possess multiple hidden contrasting color signals,but only one is associated with increased body size

Antipredatory displays that incorporate hidden contrasting coloration are found in a variety of different animals. These displays are seen in organisms that have drab coloration at rest, but when disturbed reveal conspicuous coloration. Examples include the bright abdomens of mountain katydids and the colorful underwings of hawk moths. Such hidden displays can function as secondary defenses, enabling evasion of a pursuant predator. To begin to understand why some species have these displays while others do not, we conducted phylogenetic comparative analyses to investigate factors associated with the evolution of hidden contrasting coloration in leaf‐footed bugs. First, we investigated whether hidden contrasting coloration was associated with body size because these displays are considered to be more effective in larger organisms. We then investigated whether hidden contrasting coloration was associated with an alternative antipredatory defense, in this case rapid autotomy. We found that leaf‐footed bugs with hidden contrasting coloration tended to autotomize more slowly, but this result was not statistically significant. We also found that the presence of a body size association was dependent upon the form of the hidden color display. Leaf‐footed bugs that reveal red/orange coloration were the same size, on average, as species without a hidden color display. However, species that reveal white patches on a black background were significantly larger than species without a hidden color display. These results highlight the diversity of forms that hidden contrasting color signal can take, upon which selection may act differently.     

缘蝽科四种昆虫同工酶鉴别（半翅目：缘蝽科）

本研究运用聚丙烯酰胺垂直板电泳技术对缘蝽科4个种的酯酶同工酶进行了检测,酯酶酶谱可分为4个区,酯酶酶谱在属间表现明显差异,在属内具有某些共性,聚类分析显示4个种的分类地位,并说明性别差异大于个体差异但小于种间差异。     

Comparison of damage to Eucalyptus caused by Amorbus obscuricornis and Gelonus tasmanicus

Amorbus obscuricornis (Westwood) and Gelonus tasmanicus (Le Guillou) (Heteroptera: Coreidae) are specific to Eucalyptus (Myrtaceae). A. obscuricornis feeds almost exclusively upon apical shoots and causes a characteristic wilting and necrosis. By comparison, the feeding activities of G. tasmanicus result in no obvious phytotoxicosis. Salivary gland extracts from both species exhibited sucrase activity but no pectinmethylesterase (PME) activity. Saliva from A. obscuricornis also exhibited considerable oxidase activity. Sucrase activity was significantly higher in extracts derived from G. tasmanicus than from A. obscuricornis, but this could not explain the observed differences in phytotoxic symptoms. It is suggested that differences in plant damage are attributable to the site of feeding activity (i.e. young versus mature tissue), which predetermines the reactivity of host tissues, and/or the quantity of salivary enzymes injected.     

Interpopulation variation in egg size in the winter cherry bug relative to oviposition site selection

To investigate whether or not oviposition on substrates other than host plants (e.g., non‐host plants, abiotic materials) would affect the evolution of egg size in phytophagous insects, we studied the winter cherry bug, Acanthocoris sordidus (Thunberg) (Heteroptera: Coreidae), as a model organism for its interpopulation variation in oviposition preference. The rate of oviposition off host plants is much higher in the Amami Island population than in either the Kyoto or Kochi populations. We compared egg size and number among the three local populations from Kyoto, Kochi, and Amami Island. In addition, to evaluate the adaptive significance of larger eggs for offspring in terms of searching for host plants, we examined the relationship between egg size and first‐instar body size. We also searched for a relationship between egg size and starvation tolerance in the second instars because first instars can develop to second instars without food intake, and thus the substantial host‐searching stage is the second instar, when females lay their eggs off host plants. Females from the Amami population produced fewer larger eggs than females from either the Kyoto or Kochi population. Regardless of the local population, the body size of first instars that emerged from larger eggs was larger, and the second instars originating from larger eggs had a higher starvation tolerance. The larger body size and higher starvation tolerance should enable nymphs to disperse further, which may enhance the probability of successfully reaching host plants. These results suggest that egg size in A. sordidus may be determined in relation to its oviposition habits to maximize reproductive success, resulting in interpopulation variation in egg size.     

Egg-laying tactic in Phyllomorpha laciniata in the presence of parasitoids

Female insects are expected to choose oviposition sites that have the best conditions for offspring development and survival. Natural enemies, such as predators and parasitoids, may have a strong influence on the selection of oviposition substrates by phytophagous insects. The golden egg bug, Phyllomorpha laciniata (Villers) (Heteroptera: Coreidae) has an unusual reproductive strategy. Females mainly use conspecifics, both males and other females, as egg-laying substrates, but occasionally they oviposit on plants as well. Survival of the eggs is higher when eggs are carried by conspecifics than when they are laid on plants, due to predation and parasitism. We investigated egg-laying behavior in the forced presence of the egg parasitoid Gryon bolivari (Giard) (Hymenoptera: Scelionidae). Specifically, we studied whether females provide egg protection by avoiding oviposition under the risk of egg parasitization. We expected a lower oviposition rate under parasitoid presence, and the eggs, if any, to be placed preferably on conspecifics and not on plants, thus ensuring higher survival of the progeny. The results show that P. laciniata 's egg-laying rate was lower when they were enclosed with parasitoids than when parasitoids were absent, especially when plants were the only substrate to oviposit on. Moreover, females showed strong preference for laying eggs on conspecifics rather than on plants. Egg-laying in P. laciniata appears to be not only influenced by the availability of conspecifics, but also by the presence of egg parasitoids. This indicates that females may be able to detect G. bolivari and avoid oviposition when parasitoids are present. We discuss the possibility of conspecifics as enemy-free space.     

棘缘蝽属中国种类的修订：半翅目：缘蝽科

本文是棘缘蝽属中国种类的一次分类修订。共记载７个种,对国内已有文献中的若干问题作了澄清,并发现雄性外生殖器为可靠的种类鉴别特征。     

Xylem transport interruption byAnasa tristis feeding causesCucurbita pepo to wilt

The plant tissues ingested byAnasa tristis (DeGeer) (Heteroptera: Coreidae) and the wilting ofCucurbita pepo L. (Cucurbitaceae) caused byA. tristis were investigated by feeding and light microscopy studies.Anasa tristis ingests both cell contents and xylem. Wilting of leaves and young plants byA. tristis is due to the interruption of all xylem transport to the plant apical to the feeding site. Xylem transport is interrupted by blockage, of xylem vessels with salivary secretions or severing of xylem vessels byA. tristis stylets. Restricting feeding sites by caging demonstrates that squash bug does not produce a toxin that is responsible for wilting.