Sound production in some triatomine bugs

ABSTRACT. Adults of five species of Triatominae were found to stridulate when handled: Triatoma protracta, T. lenti, T. infestans, Panstrongylus megistus and Dipetalogaster maximus. All five larval stages of D. maximus were also found to stridulate. Stridulation is caused by the tip of the reflexed proboscis rubbing along the transversely ridged prosternal groove. Each syllable of the resulting song is produced by a single antero-posterior movement of the proboscis and contains 80–150 intrasyllabic spikes, each corresponding to the striking of a single ridge in the prosternal groove. Analysis of tape recordings of the songs showed that all species have a broad frequency band without well-defined maxima, extending into the ultrasonic with frequencies of up to 50–100 kHz. The lowest frequency produced by each species is consistent with the repetition rate of the striking of prosternal ridges by the proboscis. No behavioural response to the replayed song was detected, but when the song was replayed to female P. megistus the frequency of action potentials within the antennal nerve correlated well with the intrasyllabic spike frequency of the replayed song. Possible microphonic artefacts were not, however, excluded. Possible functions of the song are discussed.     

臭虫的再猖獗、生物学及防治研究进展

由于DDT等现代杀虫剂的问世,臭虫在20世纪40-50年代以后在全球大部分地区尤其是发达国家和地区销声匿迹,但近10多年来臭虫在部分国家和地区重新出现.本文对其再猖獗原因、生物学和行为、饲养、抗药性、监测与防治策略进行了综述,旨在引起国人的重视,对今后臭虫的监测和防治起到抛砖引玉的作用.本文分析了近15年有关温带臭虫Cimex lectulariusL.和热带臭虫C.hemipterus(F.)的研究文献.臭虫再猖獗被认为是因为它对目前使用的杀虫剂例如拟除虫菊酯类等产生抗性以及频繁的地区及国际交往等因素造成的.简单、经济和大规模臭虫种群饲养方法——人工膜饲喂法的研发为我们开展臭虫生物学和生态学研究提供了便利.控制和根除臭虫目前仍较困难,采用害虫综合治理(integrated pest management,IPM)策略,包括臭虫知识宣传、主动监测、非化学防治方法(例如:经常洗涤床上用品、蒸汽熏蒸、热处理、使用床垫罩、在家具腿下放置臭虫拦截装置)、有选择使用杀虫剂以及定期监测及反复防治等措施,可达到很好的防控效果.在我国部分地区,臭虫发生也呈上升趋势,工人宿舍和火车车厢是常见的臭虫为害环境.有必要对我国臭虫发生现状及其抗药性进行调查与监测.还应借鉴国际先进技术,研制出我国适用的、有效的监测工具和防治方法,并根据我国具体国情制定出切实可行的防治标准.同时积极开展臭虫科普宣传,做到早发现、早防治,防止臭虫再猖獗和扩散.     

Alkaloids of some Mexican Zanthoxylum species

Two new 4-quinazolone alkaloids have been isolated from seed husks of Zanthoxylum arborescens. Based on their spectroscopic properties they have been assigned structures, 1-methyl-3-(2′-phenylethyl)-1H,3H-quinazoline-2,4-dione and 1-methyl-3-[2′-(4″-methoxyphenyl)ethyl]-1H,3H-quinazoline-2,4-dione. These structural assignments have been confirmed by synthesis. Skimmianine has been obtained from leaf extracts of Z. dimoncillo and Z. caribaeum while skimmianine and scopeletin have been isolated from leaf extracts of Z. fagara.     

Diel organization of behaviour in milkweed bugs, Oncopeltus spp.

ABSTRACT. Daily cyclic activities in various behaviours were similar in three species of tropical Oncopeltus (Heteroptera, Lygaeidae). Opposition in females and general movement in both sexes peaked in the middle to late light period. In contrast, feeding and mating peaked at the end of the light period and the beginning of the dark respectively. Other behaviours also tended to display one or the other of these patterns. The diel timing of behaviour observed in this study essentially duplicated the periodicities of a migratory population of Oncopeltus fasciatus from Iowa. The similarity of results across species and populations suggests a general pattern for the genus which probably serves to synchronize behaviours with environmental cycles and appropriate physiology. This similarity is interesting in view of the broad geographical range of the genus across both temperate zone and tropics and in view of the differences among populations with respect to photoperiodic determination of diapause.     

Subsocial behaviour in Oniticellus cinctus (Coleoptera, Scarabaeidae): effect of the brood on parental care and oviposition

ABSTRACT. In Oniticellus cinctus (F.) the nest chambers each contain about twenty brood balls. Females enlarge the brood balls during the egg and larval stages and remain in the chamber for the whole period of brood development (1 month); they then make a new nest after 1 week. The presence of the brood releases parental care and ensures that the mother remains in the nest: she repairs defects in the brood balls and the nest, and expels other O. cinctus females. A new ball is formed around a naked O. cinctus larva, but larvae of other species are killed. In addition, the brood inhibits oviposition: removal (or addition) of brood balls stimulates (or inhibits) egg laying. In inhibited ovarioles, existing follicles are resorbed and production of new ones ceases. Control of clutch size by the brood is an adaptation to the nest structure and life history of O. cinctus. It may have an important role in the reproductive strategy of other insects with parental care.     

Residual toxicity of some insecticides on the predatory bugs Dicyphus tamaninii and Macrolophus caliginosus

Chlorpyrifos, formetanate, methamidophos, imidacloprid and endosulfan were tested in the laboratory for their effects upon the mirid bugs Dicyphus tamaninii and Macrolophus caliginosus, which are polyphagous predators used for IPM programs in some vegetable crops. The mortality of third-fourth instar nymphs was checked 24 and 48 hours and 7 days after exposure to 1-, 3-, 8-, 21- and 30-day residues of the treatments on tomato leaflets. The reproductive capacity of surviving females also was evaluated for 15 days and compared with females that had not been exposed to insecticides. Chlorpyrifos, formetanate and methamidophos are considered persistent because they remained toxic to both mirid species for 30 days. Imidacloprid is moderately persistent, becoming harmless by 21 days after treatment for M. caliginosus and by 30 days after treatment for D. tamaninii. Endosulfan is moderately persistent for M. caliginosus, becoming harmless by 21 days after treatment, and is short lived for D. tamaninii, becoming harmless by 3 days after treatment. There were no effects on the reproductive capacity of females that were exposed as nymphs to the insecticides tested. Of all the insecticides, only endosulfan is marginally compatible with the use of D. tamaninii.     

Peculiarities of the biology of corn bugs (Heteroptera, Scutelleridae) in Samara Province

Expansion of the ranges of corn bugs (Heteroptera, Scutelleridae) north-westwards has to a large extent determined the peculiarities of their biology. The species composition of the population, development cycle, seasonal and long-term dynamics of the abundance of corn bugs and dependence of their development on food plants in the northern part of their distribution are analyzed. Disruption of this dependence is revealed, which results in great loss of corn crops. The role of the species of corn cultures and weather conditions in the dynamics of the abundance of the northern population of pests is shown.     

Amino acid determination in some edible Mexican insects

Summary The amino acid contents of edible insects from different provinces of Mexico and reference proteins were analysed by reversed-phase high-performance liquid chromatography and ion exchange chromatography. The insect amino acid contents were higher than the adult requirements indicated by the WHO/FAO pattern.     

The biology of some Argiope species from New Guinea: predatory behaviour and stabilimentum construction (Araneae: Araneidae)

Three species of Argiope: A. picta, A. aemula and A. reinwardti were studied at Wau, New Guinea. The stabilimenta in 548 webs of these species were classified into 18 categories, and the frequency of occurrence of each category was recorded. The data from this study are compared with previous records on the variation in the form of the devices built by spiders of the genera Argiope and Gasteracantha and related to theories about stabilimentum function.
Studies of the predatory behaviour of the three species show that this is, in general, similar to that of Argiope argentata . Data are cited to show that the spiders discriminate lepidopterans from insects of similar size. Particular attention was paid to the question of whether the species interrupt predatory sequences, after the attack phase, with a stage during which they rest at the hub of the web before transporting the prey. Unlike Argiope argentata these species interrupt a high proportion of predatory sequences that are initiated by bite/wrap attacks. This aspect of their behaviour is evaluated and discussed.     

Metabolic engineering of microorganisms for biofuels production: from bugs to synthetic biology to fuels

The ability to generate microorganisms that can produce biofuels similar to petroleum-based transportation fuels would allow the use of existing engines and infrastructure and would save an enormous amount of capital required for replacing the current infrastructure to accommodate biofuels that have properties significantly different from petroleum-based fuels. Several groups have demonstrated the feasibility of manipulating microbes to produce molecules similar to petroleum-derived products, albeit at relatively low productivity (e.g. maximum butanol production is around 20 g/L). For cost-effective production of biofuels, the fuel-producing hosts and pathways must be engineered and optimized. Advances in metabolic engineering and synthetic biology will provide new tools for metabolic engineers to better understand how to rewire the cell in order to create the desired phenotypes for the production of economically viable biofuels.     

Survivorship of an ant-tended membracid as a function of ant recruitment

I used a host-visitor modeling framework to examine the interaction between the treehopper Publilia concava and ants in the genus Formica. In particular, I tested the functional relationship between ant tending, the spatial distribution of treehoppers, and treehopper density. The per-capita density of ants at each host plant was a decreasing function of treehopper density, distance from the ant nest and the neighborhood density of treehoppers. Treehopper survivorship was proportional to the per-capita density of ants and the duration of ant tending. Consequently, treehoppers in low-density aggregations on isolated host plants near the nest received maximum benefit from ant tending. Treehoppers tended by the ant Formica integra were abandoned as the summer progressed, although many of these treehoppers were re-colonized by other species of ants. While F. integra ultimately abandoned all treehoppers, treehoppers on host plants with fewer initial ants were abandoned first. Results from the present study are consistent with previous findings suggesting that patterns of density-dependent benefit for homopterans are a function of the recruitment response of ants. Additionally, results suggest a tradeoff between maximizing the persistence or probability of ant-tending and minimizing competition for ants when tended. In general, host-visitor models of mutualism may provide a theoretical framework for understanding conditional outcomes in ant-homopteran, and other host-visitor mutualisms.     

A comparison of the correcting behaviour exhibited by two milkweed bugs, Oncopeltus fasciatus and Lygaeus kalmii

ABSTRACT. Adults and nymphs of two species of milkweed bugs, Oncopeltus fasciatus and Lygaeus kalmii , were studied with respect to their optomotor responses, as exhibited by the laboratory phenomenon of correcting behaviour on mazes. It was found that the O.fasciatus nymphs failed to correct while the other three groups all exhibited correcting behaviour. The differences in correcting behaviour were attributed to differences in such ecological variables as degree of socialness, nature of food source, and foraging strategies.     

On some generative orders of behaviour

The sociobiological fashion has for a long time discouraged the development of theories of the immediate causation of behaviour. It is only recently that new approaches are being developed to improve on the classical ethological theory originated by Lorenz and Tinbergen. One new departure is behavioural field theory (BFT) which brings back the concept of energy in behaviour, without being susceptible to the drawbacks of the energy or fuel concept of classical theory. In this paper the new theory is explained in some detail and it is shown to be illuminating, predictive and testable in examples of play-like and territorial behaviour.