中国鳃金龟蛹的分类研究

通过对多年积累的金龟子蛹的形态学研究,系统描述了鳃金龟蛹的基本形态特征,首次编制了我国已知13属30种鳃金龟蛹的分种检索表。鳃金龟蛹的主要分类依据为:唇基、上唇及触角形状,额区特征,前胸背板形状,腹部背板有无发音器,发音器的数量及形状,腹部背板中纵线的形态,气门颜色及形状,尾部形状,尾角的有无;雄蛹外生殖器的形状,阳基侧突和阳茎端的形状;雌蛹臀节腹面形态、生殖孔形状及位置等。     

Digestion of microbial biomass, structural polysaccharides, and protein by the humivorous larva of Pachnoda ephippiata (Coleoptera: Scarabaeidae)

In order to investigate whether microbial biomass and its residues are nutrient and energy sources for humivorous beetle larvae, we carried out feeding trials using soil supplemented with ¹⁴C-labeled fungal biomass (Penicillium chrysogenum), bacterial biomass (Bacillus megaterium), fungal or bacterial structural polysaccharide (chitin, peptidoglycan), bacterial protein, or cellulose, taking the larva of the cetoniid beetle Pachnoda ephippiata (Coleoptera: Scarabaeidae) as a model of a humus-feeding beetle larva with a highly alkaline gut. The results showed that gut passage strongly stimulated the mineralization of the structural polymers. The stimulatory effect correlated positively with the recalcitrance of the preparation in the control soil, and was accompanied by a transformation of the residual radiolabel to alkali-soluble and acid-soluble products. The solubility increase was highest in the extremely alkaline midgut. High-performance gel-permeation chromatography demonstrated that the changes in solubility were accompanied by reciprocal changes in the molecular weight of the residual material and that the residual material in the fecal pellets was more humified than in the control soil. The amount of radiolabel recovered from the body and hemolymph of the larvae indicated that microbial biomass and its structural components were assimilated more efficiently than cellulose, which supports the hypothesis that microorganisms and the nitrogenous components of humus are an important dietary resource for humivorous soil macroinvertebrates.     

Secondary seed dispersal by dung beetles in an Amazonian forest fragment of Colombia: influence of dung type and edge effect

Seeds of many plant species are secondarily dispersed by dung beetles, but the outcome of this interaction is highly context‐specific. Little is known about how certain anthropogenic disturbances affect this plant–animal interaction. The aims of this study were to assess the effect of dung type on secondary dispersal by dung beetles in a forest fragment, and to determine whether this interaction is affected by edge effects. Using pitfall traps, we captured dung beetles attracted to dung of 2 frugivorous mammals: woolly monkeys and howler monkeys. We found differences between both dung beetle assemblages, but these differences were not consistent in time. Using seeds surrounded by both dung types, we carried out a field experiment using seeds of 2 plant species. We found that the probability of secondary dispersal by dung beetles was higher for seeds placed in woolly monkey dung. Finally, we carried out a field experiment using plastic beads as seed mimics to assess edge effects. We found that secondary seed dispersal by dung beetles was negatively affected by edges. The disruption of plant–animal interactions along anthropogenic forest edges could have long‐term negative effects on forest dynamics by affecting processes of regeneration.     

Grazing promotes dung beetle diversity in the xeric landscape of a Mexican Biosphere Reserve

We analyze the impact of grazing on dung beetle diversity at the Barranca de Metztitlán Biosphere Reserve, a xeric ecosystem in central Mexico with a long history of use by humans. We compared the community structure, as well as the alpha and beta diversity between two cover conditions (open and closed vegetation) that represent the impact of grazing within a habitat, and between habitat types (submountainous and crassicaule scrublands). From 576 samples we collected 75,605 dung beetles belonging to 20 taxa. While mean species richness and diversity were different between habitat types, cumulative species richness was not. The effects of grazing on vegetation structure influenced the cumulative species richness and diversity of dung beetles in the submountainous scrubland, where grazing has created land mosaics of a grassland matrix with scrubland patches. This was not the case in the crassicaule scrubland where the impact of grazing is not as evident. Beta diversity significantly responds to the effects of grazing on habitat conditions. We discuss the ecological factors that may promote these responses by landscape diversity components. We also identify the species that could act as useful indicators to monitor the effect of land management on biodiversity. Our results indicate cattle farming maintains a diversified land mosaic, and these areas support more diverse dung beetle ensembles than homogeneous areas of closed, shrubby vegetation cover. Thus, controlled grazing activity could certainly favour the conservation of dung beetle biodiversity and improve ecosystem functioning by maintaining dung decomposition rates.     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Redesigning sugarcane for resistance to Australian canegrubs: a potential IPM component

Current management options to minimize the impact of canegrubs (larvae of melolonthine scarabs) on Australian sugarcane are heavily dependent on the use of synthetic insecticides. In developing a successful integrated pest management (IPM) programme for canegrubs, control options must be broadened. Plant resistance offers the potential for an easily deliverable and environmentally acceptable management option. Previous anecdotal reports suggest that Australian cultivars vary in their resistance to canegrubs. Many sugarcane clones (Saccharum spp. complex hybrids) have been screened and our studies have shown that there is variability in resistance through the reduction of the amount of tops, roots and stubble and in their effects on canegrub development and survival. Proteinase inhibitors, lectins and avidin have been identified as having activity against Australian canegrubs and are being introduced into the sugarcane genome. Toxins from Bacillus thuringiensis have shown little potential and are not being used further. We present a rationale for using resistant plants as a control option and for the incorporation of plant resistance into the breeding programme. Projected research will screen more sugarcane clones for resistance, study the nature of inheritance, identify chemical mechanisms involved in antibiotic effects, screen further antimetabolites for possible incorporation into the genome, prove the potential resistance of genetically engineered plants and incorporate plant resistance into an IPM programme for canegrubs.     

Sampling Efficacy and Survival Rates of Labarrus pseudolividus (Coleoptera: Scarabaeidae) and Onthophagus taurus (Coleoptera: Scarabaeidae) Using Flotation and Sieve-Separation Methodology

Understanding collection methodologies and their limitations are essential when targeting specific arthropods for use in habitat restoration, conservation, laboratory colony formation, or when holistically representing local populations using ecological surveys. For dung beetles, the most popular collection methodology is baited traps, followed by light traps and unbaited flight-intercept traps during diversity surveys. A less common collection method, flotation, is assumed to be laborious and messy, and so only a handful of papers exist on its refinement and strengths. Our purpose was threefold: First, we tested the recovery and survival rates of Labarrus (=Aphodius) pseudolividus (Balthasar) and Onthophagus taurus (Schreber) when floating beetle-seeded dung pats to determine potential collection and safety issues. We collected 72.4 and 78% of the seeded L. pseudolividus and O. taurus, respectively, with >95% survival rating. Second, we developed a flotation-sieving technique that enables users to rapidly collect and passively sort dung beetles with less time and effort. Specifically, we often collected 50–100 g of wild dung beetles within a couple of hours of gathering dung and sorted them in a couple more by allowing dung beetles to sort themselves by size within a series of sieves; Third, we reviewed flotation-based advantages and disadvantages in comparison to other methodologies.     

Susceptibility of the taro beetle,Papuana uninodis,to entomopathogenic nematodes

Six strains of entomopathogenic nematodes, Steinernema glaseri (Steiner) (Biosys #326, nc 34, gb), S. feltiae = bibionis (Filipjev) (Biosys #349), S. carpocapsae Weiser (Biosys #25) and Heterorhabditis zealandica Poinar, were evaluated in laboratory tests against taro beetles, Papuana uninodis Prell. Larvae of this species and adult Papuana Arrow spp. were found to be susceptible to entomopathogenic nematodes. The best results were obtained with S. glaseri #326 in larval and adult P. uninodis . The dose causing 50% mortality (LD ) for third instar P. uninodis larvae in Petri dish assays ranged from almost 7000 nematodes/larva for 1 days exposure to less than 250 nematodes/larva for 6 days; in pot assays the concentration causing 50% mortality (LC ) in 2 weeks was 1.4 106 nematodes/m2. For 50 adults in Petri dishes with soil, the LD was ca 20 000 nematodes/ 50 adult for 1 weeks exposure and ca 6000 nematodes/adult for 3 weeks. In pot assays the LC was 2.5 106 nematodes/m2 in 3 weeks. 50 Preliminary tests showed that P. huebneri (Fairmaire) and P. woodlarkiana laevipennis Arrow adults were also most susceptible to S. glaseri #326. A field test on adults Papuana uninodis did not result in damage reduction but served to illustrate the practical difficulties of applying nematodes in remote areas. 50     

First Report of Oryctes rhinoceros nudivirus (Coleoptera: Scarabaeidae) Causing Severe Disease in Allomyrina dichotoma in Korea

Oryctes rhinoceros nudivirus (OrNV) has been known to cause severe disease in coconut palm rhinoceros beetle, Oryctes rhinoceros, in Southeastern Asia and is used as a biological control to reduce the pest population. Here, we report for the first time that the OrNV may have landed on Korea and may be the major pathogen for diseased larvae of Korean horn beetle, Allomyrina dichotoma. After peroral inoculation, over 60% of infected larvae perished in 6 wk. This viral disease spreads very fast in several locations throughout Korea. This threat not only makes economic loss of local farms rearing A. dichotoma larvae but also may disturb the ecosystem by transmitting to wild A. dichotoma.