Topic
Sphaeridium
About: Sphaeridium is a research topic. Over the lifetime, 23 publications have been published within this topic receiving 352 citations.
Papers
TL;DR: Differences in movements of two closely related and abundant beetles are suggested to decrease the spatial coincidence between species, which decreases the intensity of interspecific competition, and may allow ecologically similar species to coexist in the same community.
Abstract: SUMMARY (1) This paper describes the within-pasture and between-pasture movements of two closely related and abundant beetles, Sphaeridium lunatum and S. scarabaeoides (Coleoptera: Hydrophilidae), feeding and breeding exclusively in cow pats. (2) Sphaeridium lunatum occurs, on average, in older pats than S. scarabaeoides and in both species, mature females occur in older pats than males or immature females. The difference in the colonization pattern between the sexes results from differences in the rates of immigration to and emigration from pats. Females arrive at fresh pats earlier than males, but mature females, unlike immature ones, are likely to leave the pat rapidly; if they stay, they will stay a long time. Density-dependence in the rate of emigration was shown experimentally and was observed in the field. (3) The proportion of individuals with an empty gut was lowest amongst resident immature females, which were probably mostly feeding, higher amongst resident males and mature females, and highest amongst arriving individuals. These results suggest that feeding and breeding are partly conflicting activities in the time budget of these beetles. (4) In S. scarabaeoides, immature females predominate amongst long-distance migrants (the oogenesis-flight syndrome), but in S. lunatum, males and mature females also frequently move long distances. On the whole, S. lunatum showed more long-distance movements than S. scarabaeoides. Other differences exist between mature and immature females. (5) These results are discussed in relation to hypotheses about the function of movements in different individuals. A new hypothesis is put forward to explain the behavioural differences between the species. We suggest that such differences in movements decrease the spatial coincidence between species, which decreases the intensity of interspecific competition, and may allow ecologically similar species to coexist in the same community.
47 citations
TL;DR: The effect of Ivermectin treatment of cattle on the rate of dung beetle colonization of cow pats was assessed by pitfall trapping in Denmark, Tanzania and Zimbabwe as discussed by the authors.
Abstract: The effect of ivermectin treatment of cattle on the rate of dung beetle colonization of cow pats was assessed by pitfall trapping in Denmark, Tanzania and Zimbabwe. Ivermectin was injected subcutaneously into heifers at the recommended dose of 0.2 mg/kg body weight, and dung to be used as bait in pitfalls was collected at intervals after treatment. In one experiment in Denmark, species of the scarab beetle Aphodius and the hydrophilids Sphaeridium and Cercyon, preferred control dung from untreated cattle; no preference was found in two other experiments, involving some of the same species. In the Tanzanian trials, the overall tendency for scarabaeid beetles was to prefer control dung. In Zimbabwe, two scarabaeid species (Euoniticellus intermedius (Reiche) and Liatongus militaris (Castelnau), both belonging to Oniticellini) were particularly attracted to dung from treated cattle; two other scarabaeids showed no preference. It is concluded: 1. That ivermectin therapy can affect the rate of dung colonization by attracting or repelling beetles. 2. That the responses are probably not caused by ivermectin per se, but by some side effect, the nature of which is obscure and unpredictable with our present knowledge.
45 citations
TL;DR: The ability to regulate respiration, and hence to extract 02 at very low concentrations, is exceptional even among terrestrial arthropods living in soil or other potentially hypoxic substrates.
Abstract: . The rate of O2 consumption was measured in five coprophilous beetle species (common in Denmark) at O2 concentrations from 1–21%. With the exception of the mainly soil-living Geotrupes spiniger (Marsham) (Geotrupidae), these beetles are probably exposed to severe hypoxia in fresh cattle pats. Aphodius fossor (Linnaeus), A. contaminatus (Herbst) (Aphodiidae) and Sphaeridium lunatum Fabricius (Hydrophilidae) maintained normal movements and a normal rate of 02 uptake (for at least 30 min) at only 1% O2. There is no evidence, therefore, that the beetles switch to anaerobic metabolism under these conditions. This ability to regulate respiration, and hence to extract 02 at very low concentrations, is exceptional even among terrestrial arthropods living in soil or other potentially hypoxic substrates. In A. rufipes (Linnaeus), respiration declined at ambient concentrations below 2% O2, and in G. spiniger the ability to regulate respiration seemed to fail at even higher concentrations. In four of the species (G. spiniger was not tested), about 11% CO2 (the level in a dung pat at 2% O2) did not affect the O2 uptake at 2% O2.
39 citations
TL;DR: It is concluded that soil type influenced both adult habitat selection and reproduction, while slope aspect had less effect and Aphodius reproduction may be risky in wet clay soils because of mortality in over-wintering individuals.
26 citations
TL;DR: During a study 20 hydrophilid beetle species and 2,457 individuals of beetles belonging to 4 genera: Cercyon, Cryptopleu- rum, Megasternum and Sphaeridium were collected, and phoretic deutonymphs were not present on the body surface of hydrophils throughout the whole period of this study.
Abstract: During a study 20 hydrophilid beetle species and 2,457 individuals of beetles belonging to 4 genera: Cercyon, Cryptopleu- rum, Megasternum and Sphaeridium were collected. On the surface of the bodies of 59 beetles (2.40% of the beetles collected) belonging to six species, 174 cases of phoresy (55 deutonymphs of Uropoda orbicularis (Muller, 1776) and 119 pedicels without deutonymphs) were observed. New hydrophilid beetle carriers of phoretic deutonymphs of U. orbicularis are given. Most mites were carried by Sphaeridium species. The population dynamics of both groups of arthropods was also studied. Most cases of phoresy were recorded in May and in the second half of July. However, phoretic deutonymphs were not present on the body surface of hydrophilid beetles throughout the whole period of this study.
25 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2017 | 2 |
| 2014 | 1 |
| 2011 | 2 |
| 2010 | 1 |
| 2009 | 1 |
| 2005 | 1 |