Characterization of galeal chemosensilla in the adult Colorado beetle, Leptinotarsa decemlineata

ABSTRACT. Approximately fifteen gustatory sensilla are present on the galeae of adult Colorado potato beetle, Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae). In the SEM, these sensilla are not distinguishable morphologically, but some of them differ physiologically. All are sensitive to sucrose, while only a few respond to gamma amino butyric acid (GABA). One, called the alpha sensillum, is significantly more sensitive to GABA than the others. The same sensory cell predominates in the alpha sensillum responses to GABA and sucrose. This example of differential specificity among sensilla, in an apparently uniform sensory field, is discussed.     

The species composition and diversity of tree-dwelling beetles in deciduous oak and evergreen forests in central Japan; Relationship between the diversity index and sample size

During the period fromlate May through December 1981, tree-dwelling beetles were regularly surveyed at three deciduous oak and two evergreen forests in the vicinity of Gifu City. Chrysomelidae and Curculionidae were abundant in these forests. The species diversity and the seasonal succession of species were most apparent in May and June. The three deciduous oak forests, with many species and high equitability, showed more diverse community structure, but fewer individuals, when compared with the two evergreen forests. Furthermore, the species compositions of the deciduous oak forests were seasonally and spatially more heterogeneous than those of the evergreen forests. A few dominant species, however, had a strong influence on the community structure. The relationship between the diversity index and sample size was examined. The diversity index changed with the sample size, and the range of the variation diminished as the sample size increased. However, equilibrium was not reached even in the largest sample size used in this study (20 samples). There was a significantly high correlation (P<0.001) in diversity index between the smaller sample sizes (5, 10, 15) and the largest. It was, therefore, shown that community structures can be compared on the basis of the diversity indices from samples of constant size, even when the samples are small. Contribution No. 108 from Lab. Ent., Fac. Agr., Gifu Univ.     

Getting the most out of waste: how dung beetles boost the nitrogen content in their food

The life cycle of almost all dung beetles revolve around mammalian dung, the feed on dung, look for mating partners on dung and lay eggs in the dung. We know they feed on dung, but we still do not understand how exactly they filter‐feed on the dung and which particles size range they are ingesting. The aim on this study was to investigate the filter feeding by particle selection by adult dung beetles using Scarabaeus goryi and how that improves the nutrient quality of the ingested particles. We compared the particle sizes and nutrient content of the dung with the ingested material in the foregut, hindgut and the faeces of the dung beetle. Adult dung beetles do select smaller dung particles when feeding, we found the maximum particle size for the ingested particle to be around 1400 μm. The average particle size increased through the gut length. Dung beetles also selected particles with higher nitrogen content when feeding, the nitrogen content increased from about 1.5% in the dung to just over 5% in the foregut which then decreased to the level of the unprocessed dung in the dung beetle faeces. Carbon content did not increase from the unprocessed dung to the foregut but decreased through the gut length. Feeding by particle size selection by dung beetles helps in selecting particles with higher nitrogen content to compensate for the low levels found in dung.     

Are we doomed to repeat history? A model of the past using tiger beetles (Coleoptera: Cicindelidae) and conservation biology to anticipate the future

Studies of conservation biology involving tiger beetles have become increasingly common in the last 15 years. Governments and NGOs in several countries have considered tiger beetles in making policy decisions of national conservation efforts and have found tiger beetles useful organisms for arguing broad conservation issues. We trace the evolution of the relationship between tiger beetle studies and conservation biology and propose that this history may in itself provide a model for anticipating developments and improvements in the ability of conservation biology to find effective goals, gather appropriate data, and better communicate generalizations to non-scientific decision makers, the public, and other scientists. According to the General Continuum of Scientific Perspectives on Nature model, earliest biological studies begin with natural history and concentrate on observations in the field and specimen collecting, followed by observing and measuring in the field, manipulations in the field, observations and manipulations in the laboratory, and finally enter theoretical science including systems analysis and mathematical models. Using a balance of historical and analytical approaches, we tested the model using scientific studies of tiger beetles (Coleoptera: Cicindelidae) and the field of conservation biology. Conservation biology and tiger beetle studies follow the historical model, but the results for conservation biology also suggest a more complex model of simultaneous parallel developments. We use these results to anticipate ways to better meet goals in conservation biology, such as actively involving amateurs, avoiding exclusion of the public, and improving language and style in scientific communication. CXLV, Studies of Tiger Beetles