435 research outputs found
Co-occurrence of mated workers and a mated queen in a colony of Platythyrea arnoldi (Hymenoptera: Formicidae)
A colony of Platythyrea arnoldi was found to contain a functional queen and laying workers, both virgin and mated. This form of social organization has never been reported in ants before
Reproductive behaviour of Plectroctena mandibularis F. Smith (Hymenoptera: Formicidae), a ponerine ant with ergatoid queens
[From the text]: The present study reports on new observations on the reproductive biology of P. mandibularis, particularly the phenology of males, mating behaviour and colony founding, that may help in deciding between alternative explanations for the occurrence of ergatoid queens in this species
Book Reviews
Book Review 1Book Title:Â Electron microscopy methods and protocolsBook Author:Â Editor M.A. Nasser HajibagheriMethods in molecular biology, Volume 117. Humana Press, Totowa, New Jersey. 1999. ISBN 0-896-03640-5. Paperback, 283 pp.Book Review 2Book Title: Identifying British insects and arachnids: an annotated bibliography of key worksBook Author:Â Editor P.C. BarnardCambridge University Press, Cambridge. 1999. ISBN 0 521 63241 2. Hardback, 533pp
IsiXhosa insect names from the Eastern Cape, South Africa
We present a list of isiXhosa names for a wide diversity of South African insects, and their English translations and scientific names, to contribute to bridging the knowledge gap between rural development workers and isiXhosa speakers. We interviewed 51 people in their homes at eight sites across the Eastern Cape and also included words from a published dictionary. We found 151 insect names, and categorized them into personal, dialectal and standard categories. Response-frequency distributions of the categories of names showed that the dialectal and standard lists were essentially complete. Sample accumulation curves showed levelling-off within sites and across the whole study, demonstrating that samples were adequate. The literal translations of some names show that isiXhosa speakers relate insects either to people, to their habitat and/or to their behaviour. The list can contribute to the standardization of knowledge of insects' indigenous names in South Africa for a variety of practical applications such as agricultural training and health services
African carrion ecosystems and their insect communities in relation to forensic entomology
African carrion communities contain representatives of the same families that occur in carrion communities on other continents. Checklists and identification guides are tabulated, and the natural histories of core members of the terrestrial community are outlined. Because of strong phylogenetic trends in the biology of the families, the species are effectively ecological surrogates of their relatives elsewhere. These phylogenetic trends also allow the definition of a set of guilds of functionally equivalent species that unify the study of carrion communities world-wide, and a revised suite of guilds is described with both synecological and forensic purposes in mind. Although the decomposition process has been arbitrarily subdivided into stages, they have little direct relation to the dynamics of the carrion community, and should be treated as landmarks rather than phases. Community turnover follows a qualitatively predictable succession, with the greatest species richness and diversity around the ecotone-like transition from ‘wet-phase’ to ‘dry-phase’ carrion habitats. These habitats are differentiated along interacting ecological gradients of dietary quality, competition, and risk of predation, which are important to the core guilds. Competition and predation have strong effects on population dynamics of community members, but link particular species only weakly, so that the succession pattern largely reflects the autecology of the individual species. Discrete waves of species are absent, which increases the temporal resolution, and therefore the forensic value, of the succession as a ‘clock’. The forensic significance of various aspects of community and trophic dynamics are discussed, and means of applying ecological theory to investigations are reviewed
Effect of the killing method on post-mortem change in length of larvae of Thanatophilus micans (Fabricius, 1794) (Coleoptera: Silphidae) stored in 70% ethanol
It is recommended that insect larvae collected for forensic purposes should be killed using the same method as was used to create existing models for rate of development. Certain killing methods have been shown to be preferable because they cause less distortion of the specimens, but these are not always practicable in a particular case, and so a method of correcting for effect of killing method is required. Larvae of all instars of Thanatophilus micans (Fabricius 1794) (Coleoptera: Silphidae) were measured and then killed by immersion in ethanol, immersion in hot water or freezing. Samples were re-measured immediately after death, then stored in excess 70% ethanol and re-measured after 1 week and again after 4 weeks. The change in length was significantly different from zero in all samples (t = -9.07022, p < 0.001). An analysis of covariance showed that instar, killing method and storage time all had a significant effect on the change in length. The results showed that T. micans larvae have a great potential for change in length during storage but that the change is not predictable, as the magnitude and sign of the change are variable
3000 miles from home: a new Gastrosericus baobabicus Pulawski, 1995 (Hymenoptera, Larridae) distribution record highlights that the Sahel has a distinct entomofaunal signature
[from introduction] On October 30, 1953, an unidentified female wasp (Fig. 1) was collected from ‘Belet Uen, Somaliland’ (= Beledweyne, 4°44’N 45°12’E), situated in the valley of the Shebelle River, HiraanProvince,Somalia. It was deposited in the aculeate Hymenoptera collection of the Albany Museum, Grahamstown by D. Greathead prior to 1968. Apart from the words ‘Somaliland’ and ‘Desert Locust Survey’ the label is handwritten and the collector’snameis not recorded. Greathead’s sister, S. Gess (Albany Museum), deciphered the label and stated that he had worked for the Desert Locust Survey, investigating the natural enemies of locusts and had been in Somalia (then Somaliland) at that time (Murphy & Cock 2007). The specimen was sent in 2004 by F. Gess to W. Pulawski, who determined it as Gastrosericus baobabicus Pulawski, 1995. Gastrosericus species prey on spiders and a variety of small insects (Pulawski 1995), including Orthoptera (Krombein & Pulawski 1986), so it is likely that Greathead collected the specimen in connection with his interest in the insect enemies of Acridoidea (Orthoptera) (Greathead 1962)
Mechanisms generating biological diversity in the genus Platypleura Amyot & Serville, 1843 (Hemiptera: Cicadidae) in southern Africa: implications of a preliminary molecular phylogeny
Truly understanding biological diversity requires a move from descriptive studies to mechanistic interpretations based on comparative biology and a thorough recognition of the natural history of the focal organisms. A useful step in such comparative studies is the generation of a phylogeny, so that one can assess the phylogenetic independence of the focal taxa and trace the evolutionary significance of their characteristics. As a preliminary to such studies on the platypleurine cicada genus Platypleura, we sequenced 498 bases of the cytochrome oxidase I (COI) gene from thirteen African species. To circumvent problems with outgroup selection, we also included sequences from representatives of the platypleurine genera Brevisiana, Capcicada, Munza, Oxypleura, Severiana, and Systophlochius, all of the subtribe Platypleuriti, and two species of the genus Ugada, of the subtribe Hainanosemiiti. The resulting phylogenies support the synonymization of the monotypic genus Systophlochius with the widespread, speciose genus Platypleura; confirm the placement of Platypleura sp. 7 in that genus; and confirm the independence of Capcicada and Platypleura. Although the preliminary phylogeny lacks strong support at many nodes, it suggests that three radiations of Platypleura have occurred in southern Africa and that there was progressive southward speciation of these radiations. A novel modification of the ancestral area analysis further suggests that the group has an ancestral association with acacias but there were five independent speciation events associated with host- switching. These insights can be summarized by a general hypothesis that the mechanisms underlying platypleurine biodiversity in southern Africa involve two ancient vicariance events and subsequent speciation by vicariance, switching of plant associations, and changes of habitat preferences. We offer this example to illustrate how analysis of preliminary data can help to generate hypotheticodeductive research hypotheses, to provoke interest in testing these hypotheses, and to illustrate the utility of phylogenies beyond systematics
Larval development of the carrion-breeding flesh fly, Sarcophaga (Liosarcophaga) tibialis Macquart (Diptera: Sarcophagidae), at constant temperatures
Larvae of Sarcophaga (Liosarcophaga) tibialis Macquart were raised on chicken liver under six different constant temperatures. Maximum survival indicated an optimal developmental temperature of near 20°C, while trends in mortality, larval length and larval mass implied that the thermal window for successful development lay between 15°C and 30°C. Using a recently described method to estimate a simple thermal summation model, it was found that the timing of the end of the feeding phase could be estimated by a developmental zero (D0) of 5.2°C (S.E. = 1.21) and a thermal summation constant (K) of 106.4 d°C (S.E. = 8.31) and of the end of the wandering phase by D0 = 4.1°C (S.E. = 0.39) and K = 126.7 d°C (S.E. = 3.28). Published development times at constant temperatures were compiled for 19 other species of flesh flies, and the developmental constants were calculated for six species for which sufficient data were accumulated
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