While the impacts of extreme and rising mean temperatures are well documented, increased thermal variability associated with climate change may also threaten ectotherm fitness and survival, but remains poorly explored. Using three wild collected coprophagic species Copris elphenor, Metacatharsius opacus and Scarabaeus zambezianus, we explored the effects of thermal amplitude around the mean on thermal tolerance. Using standardized protocols, we measured traits of high- (critical thermal maxima [CTmax] and heat knockdown time [HKDT]) and -low temperature tolerance (critical thermal minima [CTmin], chill coma recovery time [CCRT] and supercooling points [SCPs]) following variable temperature pulses (δ0, δ3, δ6 and δ9°C) around the mean (27°C). Our results show that increased temperature variability may offset basal and plastic responses to temperature and differs across species and metrics tested. Furthermore, we also show differential effects of body mass, body water content (BWC) and body lipid content (BLC) on traits of thermal tolerance. For example, body mass significantly influenced C. elphenor and S. zambezianus CTmax and S. zambezianus HKDT but not CTmin and CCRT. BWC significantly affected M. opacus and C. elphenor CTmax and in only M. opacus HKDT, CTmin and CCRT. Similarly, BLC only had a significant effect for M opacus CTmin. These results suggest differential and species dependent effects of climate variability of thermal fitness traits. It is therefore likely that the ecological services provided by these species may be constrained in the face of climate change. This implies that, to develop more realistic predictions for the effects of climate change on insect biodiversity and ecosystem function, thermal variability is a significant determinant.

Summary Anthelmintics are widely used to control gastrointestinal parasites of livestock. However, the residues of these compounds, particularly the macrocyclic lactones, are excreted largely unmetabolised in faeces, where they may have toxic effects on dung‐colonising insects. Impoverishment of the coprophagous beetle community impairs the process of dung recycling and, as a result, may enhance the persistence of dung‐dwelling helminth parasitic stages. To test this possibility, a large‐scale field trial was conducted in south‐west England. The availability of infective parasite helminth larvae (L3) was investigated on the herbage around 240 artificial 1‐kg dung pats that had been constructed from the faeces of beef cattle with naturally acquired strongyle infections. Herbage up to 15 cm surrounding each pat was sampled at 2, 4, 6, 8 and 10 weeks after deposition. Pats were subject to enhanced, natural or no dung beetle colonisation and uncontrolled or enhanced rainfall. Under uncontrolled rainfall conditions, 2 weeks after pat deposition, significantly more L3 were recovered from around pats that were exposed to beetle colonisation than from pats that were not colonised. However, by week 8, significantly fewer L3 were recovered from around pats that were exposed to beetle colonisation compared to uncolonised pats. Under conditions of enhanced rainfall, pats yielded significantly more L3 than under uncontrolled rainfall conditions, and there were no differences in recovery from herbage around pats with enhanced, natural or no beetle colonisation. The data suggest that over the duration of a summer grazing season, temperate habitat dung‐colonising insect communities, which include mainly small endocoprid dung beetles of the genus Aphodius, can reduce the development and survival of livestock gastrointestinal parasites on pastures, but that this can be overridden by the effect of high rainfall. Synthesis and applications. The work demonstrates that conservation of dung beetle populations in temperate climates is important in livestock management, not only for their essential role in dung degradation and nutrient cycling, but because their activity can also reduce the survival and availability of gastrointestinal parasites on pastures.

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Pyrethroid insecticides are widely used to control ectoparasites of livestock, particularly ticks and biting flies. Their use in African livestock systems is increasing, driven by the need to increase productivity and local food security. However, insecticide residues present in the dung after treatment are toxic to dung‐inhabiting insects. In a semiarid agricultural habitat in Botswana, dung beetle adult mortality, brood ball production, and larval survival were compared between untreated cattle dung and cattle dung spiked with deltamethrin, to give concentrations of 0.01, 0.1, 0.5, or 1 ppm. Cattle dung‐baited pitfall traps were used to measure repellent effects of deltamethrin in dung on Scarabaeidae. Dung decomposition rate was also examined. There was significantly increased mortality of adult dung beetles colonizing pats that contained deltamethrin compared to insecticide‐free pats. Brood ball production was significantly reduced at concentrations of 1 ppm; larval survival was significantly reduced in dung containing 0.1 ppm deltamethrin and above. There was no difference in the number of Scarabaeidae attracted to dung containing any of the deltamethrin concentrations. Dung decomposition was significantly reduced even at the lowest concentration (0.01 ppm) compared to insecticide‐free dung. The widespread use of deltamethrin in African agricultural ecosystems is a significant cause for concern; sustained use is likely to damage dung beetle populations and their provision of environmentally and economically important ecosystem services. Contaminated dung buried by paracoprid (tunneling) beetles may retain insecticidal effects, with impacts on developing larvae below ground. Lethal and sublethal effects on entire dung beetle (Scarabaeidae) communities could impair ecosystem function in agricultural landscapes.

Dermacentor reticulatus (Ixodida: Ixodidae, Fabricius 1794) is one of the most widely distributed and abundant tick species in central Europe and is a vector for a range of pathogens. Nevertheless, many aspects of its ecology and distribution remain poorly understood. To quantify the seasonal abundance of this species in the U.K. and the environmental factors that determine this, weekly sampling at sites throughout Wales and southern England was undertaken for 12 months. This showed that the activity of adult D. reticulatus peaked February and March and that no individuals were collected between May and mid‐October; no questing tick activity was observed when the 5‐day average temperature was greater than 15 °C. A single nymph was collected by dragging, confirming speculation over the nidicolous status of larval and nymphal stadia. Laboratory analysis found that D. reticulatus were able survive cold shock and the lower lethal temperature was estimated to be between −18 and −20 °C. Habitat was significantly associated with tick activity, with higher numbers of ticks collected from low lying vegetation in marsh environments than from exposed grassland or woodland. A strong association was observed between activity and saturation deficit suggesting that the seasonal pattern of activity seen in the field, within the sites where it was abundant, is more strongly determined by temperature than humidity. Range expansion within the U.K. should be expected, bringing with it an elevated disease risk for animal and human hosts.