Identification of a new predaceous stink bug pheromone and its attractiveness to the eastern yellowjacket

Summary Males ofPodisus fretus (Hemiptera: Pentatomidae) release a long-range attractant pheromone containing linalool (49.0%), (E)-2-hexenal (34.5%), benzyl alcohol (12.0%), nerolidol (2.0%),-terpineol (1.1%), and traces of several other compounds. The eastern yellowjacket,Vespula maculifrons (Hymenoptera: Vespidae), is attracted to artificial pheromones forP. fretus and for the sympatric species,Podisus maculiventris.The authors thank Mr T.J. Henry of the USDA Systematic Entomology Laboratory and Dr J.E. McPherson, Southern Illinois University, for examining the pentatomid species and Dr A.S. Menke, USDA-SEL, for determining the yellowjacket species. We also thank S. Wilzer for technical assistance. Mention of a company name does not imply endorsement by the US Department of Agriculture.     

Control of the behaviour of leaf-cutting ants by their ‘symbiotic’ fungus

There is an obligatory relationship between leaf-cutting ants of the generaAtta andAcromyrmex (Hymenoptera; Attini) and the fungus,Attamyces bromatificus Kreisel, for which they provide a substrate of cut plant material. We show that the ants learn to reject plant material that contains chemicals injurious to the fungus. After an initial period of acceptance, ants from laboratory nests stopped harvesting granular bait containing a fungicidal agent (cycloheximide) and orange peel. This rejection was maintained for many weeks. These colonies also rejected control bait containing no cycloheximide. Some generalisation of the response was observed; colonies rejecting orange granules also rejected grapefruit granules, although they still accepted blackcurrant granules. Rejection of fungicidal bait by colonies in the field was restricted to ants on foraging trails exposed to experimental bait. We conclude that a semiochemical from the fungus, circulated by trophallaxis and grooming, regulates the selection of plant material by foragers. The fungus gains more advantages from the symbiotic relationship than is often realised. The ants provide the fungus with housing, sanitation, defence against disease and predators, pre-selected food, and a means of dissemination, at the cost to itself of providing food for the ant brood.     

Chemical ecology of bark beetles

Summary The purview of chemical ecology and the recent criticisms of improper application of theory to bark beetle phenomena is briefly discussed. Seven levels of research in chemical ecology are presented as well as their relationship to research on bark beetles. The biology and chemical ecology of several pest bark beetles from North America and Europe are discussed in regard to host tree selection theories of random landing on trees or attraction to semiochemicals. The diversity and similarities of pheromone components among species are presented in relation to their biosynthesis from host tree precursors and in relation to the ecological implications of de novo or precursor syntheses. Individual variation in biosynthesis of, response to, and release of pheromones is discussed. Olfactory perception of semiochemicals at both the electrophysiological and behavioral levels is presented. Orientation to semiochemicals during walking and flying is discussed with reference to the significance of dose-response curves for determining a compound's functionality in short- or long-range communication. The regulation of attack density, termination of the aggregation, mechanisms of attack spacing, and recognition of host suitability are presented in the context of an individual's avoidance of intra- and interspecific competition. Finally, a brief summary of topics where our understanding of the chemical ecology of bark beetles and their associates is poorly known is presented.     

信息化合物诱芯对阔叶红松混交林中天牛科昆虫的诱集效果

于2013、2014年在吉林省蛟河林业实验区管理局阔叶红松混交林样地内布设配有天牛亚科昆虫公用信息素和乙醇诱芯的飞翔拦截诱捕器阵列采集天牛科昆虫成虫,测试各诱芯及其组合对天牛物种的诱集活性。2 a的野外诱集试验表明:诱芯及其组合对四点象天牛、凹缘金花天牛、异色蜓尾花天牛、蓝突肩花天牛、锯天牛、赤胸扁鞘天牛、栎丽虎天牛和棍腿纹虎天牛的诱集活性存在显著的差异。不同诱芯及其组合诱集到的天牛昆虫物种组成不同,且各诱芯组合诱集到的天牛物种平均数量和个体平均数量均差异显著。配以信息素3-羟基-2-己酮、3-羟基-2-辛酮诱芯的诱捕器对多种天牛亚科昆虫具有诱集活性,同时也表明其对沟胫天牛亚科和花天牛亚科的一些种类也具有引诱活性;在天牛科昆虫的调查和监测中,使用天牛亚科信息素和高释放率乙醇诱芯可显著地提高诱集调查效率。同此前研究,阔叶红松混交林中的沟胫天牛亚科、花天牛亚科和天牛亚科的种类最多、多度最高。研究表明,使用配以天牛亚科信息素和乙醇诱芯的诱捕器可有效地监测这些天牛种类的种群动态。     

Enemy-induced dispersal in a parasitic wasp

Females of the parasitic waspAphidius uzbekistanicus, a specialist aphid primary parasitoid, react to the presence of their specialist hyperparasitoid enemyAlloxysta victrix by leaving the area. The wasps leave to increase their reproductive success, because only their offspring, but not the wasps themselves, are threatened by enemy attack. Furthermore, this dispersal is elicited through the action of volatile chemical cues produced by the hyperparasitoids. We provide evidence for 6-methyl-5-hepten-2-one being one of the volatiles eliciting dispersal. The tendency of the wasps to leave areas which are being colonized by their enemies reduces their efficiency as aphid antagonists.     

Instar-specific defensive secretions of stink bugs (Heteroptera: Pentatomidae)

Defensive secretions (allomones) from first-instar nymphs of stink bugs in the subfamily Pentatominae contain (E)-4-oxo-2-decenal as a major constituent, whereas this compound is absent from later instars. In contrast, first instars ofEdessa meditabunda (Edessinae) produce allomones like those of later instars. The C₆ and C₈ (E)-4-oxo-2-alkenals are common, characteristic exocrine compounds of nymphal and adult Heteroptera, but (E)-4-oxo-2-decenal is previously unknown as a major natural product for which a biological role has yet to be established.     

A source of cutaneous maternal semiochemicals in the mink?

Summary Unique hypertrophic apocrine sweat glands are described in the neck, perineal and inguinal skin of mink kits. These glands enlarge after birth, only to regress rapidly and become vestigal by weaning. No similar phenomenon has been recognized before in mammals. Behavioral studies indicate a possible role for the glandular secretion in maternal recognition of the young.