Factors regulating predation by first-instar spined assassin bugs [Sinea diadema (Fabricius)] (Hemiptera: Reduviidae)

Selected nutritional and developmental factors regulating the predatory behavior of first-instar spined assassin bugsSinea diadema (Fabricius) (Hemiptera: Reduviidae) were investigated. The longevity of unfed nymphs provided with free water, bean pod sections, or glucose solutions was not significantly greater than that of unfed nymphs which were not provided with a source of water. First-instarS. diadema that were provided with larvae ofEphestia kuehniella Zeller (Lepidoptera: Pyralidae) as prey began feeding 1.9 (±0.9) days after hatching. In contrast, first-instarS. diadema that were provided with conspecifics of the same age did not begin feeding until they were 3.9 (±0.9) days old. These results suggest that the potential nutritional benefits to be gained from feeding equal or outweigh the risk of attacking prey capable of effective self-defense only when nymphs have not fed for 4 days after hatching. Providing the nymphs with water or glucose solutions significantly delayed the onset of conspecific predation. Additional data are presented which demonstrate that first-instarS. diadema are not restrained from preying on siblings by kin recognition.     

Comparative trichome morphology in feather-legged assassin bugs (Insecta: Heteroptera: Reduviidae: Holoptilinae)

The trichome in ant-feeding Holoptilinae (Insecta: Heteroptera: Reduviidae) comprises remarkable modifications of abdominal sternites 2 and 3. It has been hypothesized that this structure plays a role in attracting and drugging ants. In the present study the trichome of 14 species of Holoptilini, comprising 11 species of Ptilocnemus Westwood and representatives of three additional genera of Holoptilini, is examined using scanning electron and light microscopy. The astoundingly diverse species-level modifications of sternites and vestiture are described and primary homology hypotheses are proposed. The trichome provides species-specific diagnostic characters within Ptilocnemus and evidence for species-groups within the genus, but also for the sistergroup relationship of Ptilocnemus and Smiliopus Bergroth. The comparative morphology establishes a framework for investigations into systematics, functional morphology, and behavioral ecology of these myrmecophagous assassin bugs.     

Trypanosoma cruzi (Kinetoplastida Trypanosomatidae): ecology of the transmission cycle in the wild environment of the Andean valley of Cochabamba, Bolivia

An active Trypanosoma cruzi transmission cycle maintained by wild rodents in the Andean valleys of Cochabamba Bolivia is described. Wild and domestic Triatoma infestans with 60% infection with T. cruzi were found and was evidenced in 47.5% (rodents) and 26.7% (marsupial) by parasitological and/or serologycal methods. Phyllotis ocilae and the marsupial species Thylamys elegans, are the most important reservoirs followed by Bolomys lactens and Akodon boliviensis. In spite of both genotypes (TCI and TCII) being prevalent in Bolivia, in our study area only T. cruzi I is being transmitted. Our data suggest that wild T. infestans and wild small mammals play an important role in the maintenance of the transmission cycle of T. cruzi. Furthermore, the finding of high prevalence of T. cruzi infection in wild T. infestans point to the risk of the dispersion of Chagas' disease.     

中国盗猎蝽属一新记录种——红缘盗猎蝽(半翅目:猎蝽科:盗猎蝽亚科)

狭义的盗猎蝽属是猎蝽科盗猎蝽亚科中1个较大的属,已知约40个有效种,主要分布于古北区、东洋区和非洲区,中国已知6种.我们在对新疆半翅目多样性的研究过程中,发现了广布于古北区的红缘盗猎蝽Peirates hybridus(Scopoli,1763).本文重新描述了这一中国新记录种;该种体中型,体表大部分区域黑色,革片、侧...     

Hairy attachment structures in Reduviidae (Cimicomorpha, Heteroptera), with observations on the fossula spongiosa in some other Cimicomorpha

Reduviidae and some other groups of cimicomorphan Heteroptera possess a hairy attachment structure on the apex of the tibia called “fossula spongiosa”. The fossula spongiosa was never studied comparatively across Reduviidae, its fine structure and mode of function is not well documented, and attachment structures in immature stages are virtually unknown. Here, a sample of 171 species of Reduviidae representing 22 subfamilies is examined for presence-absence of the fossula spongiosa on the three pairs of legs. Representatives of 11 of the 22 subfamilies are shown to possess a fossula spongiosa. The fine structure of the fossula spongiosa is examined for a more limited sample of Reduviidae and several Pachynomidae and Nabidae. In addition, scanning micrographs for the fossula spongiosa in other Cimicomorpha are given, among them Anthocoridae, Cimicidae, Microphysidae (first record of a fossula spongiosa), and Thaumastocoridae. The fossula spongiosa in Reduviidae consists of tenent hairs (acanthae) with spatulate or tapering apices interspersed with sensory setae, both of which are embedded in a thick and flexible cuticle, underlain by a hemolymph cavity separated almost entirely from the interior of the remaining tibia by a cuticular invagination. Judging from comparison with non-reduviid Cimicomorpha, this separation of the fossula spongiosa cavity from the tibial interior may be unique to Reduviidae. A simple experiment using live specimens of Platymeris biguttata (Reduviinae) revealed a liquid on the tip of the tenent hairs that might be involved in the attachment of the fossula spongiosa by adhesion mechanisms. The nymphs of Reduviidae whose adults have a fossula spongiosa are here documented for the first time to possess pads of ventrally barbed setae instead of tenent hairs and their tibia lacks the internal cuticular invagination. The nymphal attachment structures seem to rely on increase of friction rather than the adhesion mechanism proposed to be present in the adult. Combined with the tenent setae on the third tarsomere known in some Emesinae and here documented for Saicinae, three types of hairy attachment structures occur on the legs of Reduviidae: tenent hairs (acanthae), which form the fossula spongiosa in many Reduviidae, barbed setae that substitute the fossula in the immatures, and tenent setae on the tarsus which are restricted to only a few taxa.     

瓦氏阿猎蝽--中国和越南的新记录属与种(半翅目:猎蝽科)

瓦氏阿猎蝽Agyrius watanabeorum为日本半翅目学者石川忠2002年根据采自泰国北部的标本所命名,其描记较为详细,配有正模的整体黑白照片和部分特征图,但对该种的阳茎结构没有提及。在研究中国和越南的猎蝽时,我们发现了该种。本文中我们重新描述了瓦氏阿猎蝽,绘制了较详细的整体图和局部特征图。阿猎蝽属Agyrius Stal,1863为中国和越南的新记录属,瓦氏阿猎蝽Agyrius watanabeorum Ishikawa,2002为中国和越南的新记录种;其在中国和越南的分布也是该属种最北的分布记录。     

Trypanosoma cruzi: Biological characterization of lineages I and II supports the predominance of lineage I in Colombia

The causes of the particular distribution of both Trypanosoma cruzi lineages throughout the American continent remain unknown. In Colombia, T. cruzi I is the predominant group in both domestic and sylvatic cycles. Here, we present the biological characterization of T. cruzi parasites belonging to both T. cruzi I and T. cruzi IIb groups. Our results show the inability of the T. cruzi IIb clones to infect mammalian cells, produce trypomastigotes and replicate in Rhodnius prolixus, the main vector species in this country. Moreover, this result was confirmed when other species from the same genus, such as R. pallescens and R. robustus, were infected with the same TcIIb clone and its parental strain, while the infection in other genera such as Triatoma and Panstrongylus was successful. Furthermore, the growth kinetics and duplication time in vitro suggest that the high prevalence of T. cruzi I in Colombia results from more successful interactions between parasite lineage, vector, and host species. This type of study may help to understand the factors influencing the particular epidemiological patterns of Chagas disease transmission in different endemic regions.     

Age‐specific mortality analysis of the dry forest kissing bug,Rhodnius neglectus

Age‐specific mortality patterns can be very different across insects with different life histories. Some holometabolous insects (like mosquitoes, fruit flies) show a pattern where mortality rate decelerates at older ages, whereas other holometabolous insects (bruchid beetles) and hemimetabolous insects (cotton stainers, milkweed bugs, and kissing bugs) show an age‐specific mortality pattern that increases through all ages. Kissing bugs are strictly hematophagous and are vectors of Trypanosoma cruzi Chagas, the etiologic agent of Chagas disease. Here, we tested whether cohort data from the dry forest kissing bug, Rhodnius neglectus Lent (Hemiptera: Reduviidae), supports an increase of mortality rate that decelerates with age. We analyzed the age‐specific mortality pattern of a cohort of 250 individuals of R. neglectus. We used a suite of seven models with different degrees of complexity, to model age‐dependent forms of change in mortality rate increase in R. neglectus in the laboratory. We used the Akaike model selection criterion to choose between models that consider absence or presence of mortality deceleration. Five of the seven models (logistic, Gavrilovs, Gompertz, DeMoivre, and exponential) showed a statistically significant fit to the mortality rate. Weak late‐age mortality deceleration in R. neglectus was supported by the best fit (logistic model), and this result is consistent with predictions of the disposable soma theory of senescence.     

The chemical basis of mate recognition in two parasitoid wasp species of the genus Nasonia

Triatomines (Hemiptera: Reduviidae) are vectors of Trypanosoma cruzi Chagas, the etiological agent of Chagas's disease. They display pre‐adult development delay – that is, a development time much longer than on average – which usually has been considered as a maladaptive trait. However, this hypothesis has not been tested. We carried out an experiment under controlled laboratory conditions to (1) test whether a development delay exists in the fifth nymphal stage of Rhodnius prolixus Stål (Hemiptera: Reduviidae, Rhodniini), and (2) measure any fitness cost related to such delay by estimating the relationship between individual development time and other life‐history traits. We analyzed the development time with various continuous statistical distributions (normal, log‐normal, Weibull, gamma, Pareto, Burr, and log‐logistic). Using goodness‐of‐fit tests, the best fit was obtained with asymmetrical distributions, with the Burr distribution showing the best fit to the data. We concluded that a development delay exists in stage five of R. prolixus without fitness cost. The combination of our results and previous work suggests that such a delay could be viewed as an adaptive response to environmental stochasticity and/or density‐dependence rather than as a maladaptive trait. We propose further investigations to provide a conclusive test of adaptive delay in triatomines.     

昆虫肢体再生的研究进展

文中就发生断肢再生的昆虫类群、出现虫态、再生的类型、再生能力、影响再生的因素、再生的生物学意义几个方面进行了综述 ,特别对猎蝽科昆虫的肢体再生有关方面做了介绍