Effects of cattle treatment with a fluazuron pour-on on survival and reproduction of the dung beetle species Onthophagus gazella (Fabricius).

While resistance against many other classes of acaricides has been described, products containing benzoylphenyl urea are currently still successfully used against the pesticide-resistant blue tick (Boophilus decoloratus) in South Africa. In order to assess any adverse impact of these tickicides on the important dung beetle (Coleoptera: Scarabaeidae) fauna, a bioassay was undertaken on the ecotoxicological effects of a fluazuron (benzoylphenyl urea) pour-on formulation (Acatak) on the survival and reproduction of the African dung beetles species Onthophagus gazella (Fabricius). The experiment yielded no significant differences in adult or larval survival, egg production, fecundity and fertility between the control and treatment group following three beetle generations over. These results suggested that treatment of cattle with the fluazuron pour-on formulation Acatak was not detrimental to the selected dung beetle species in any notable way.

A comparative analysis of metabolic rate in six Scarabaeus species (Coleoptera: Scarabaeidae) from southern Africa: further caveats when inferring adaptation.

Alterations in VO(2) or VCO(2) are amongst the more polemical physiological adaptations ascribed to insects. Generally, metabolic rate is thought to be lowered in response to arid conditions, and elevated in species from cold environments compared to their more temperate relatives. However, most studies have rarely addressed the influence of both environmental factors in unison. To this end, standard metabolic rate and its temperature dependence were measured (at 4 degrees C intervals from 16 to 32 degrees C) in six Scarabaeus dung beetle species (three flightless, three volant) from a variety of habitats (warm, arid to cool, mesic) in southern Africa using flow-through respirometry. Mass specific VCO(2) varied from 0.0158 ml g(-1) h(-1) at 16 degrees C to 0.1839 ml g (-1) h(-1) at 32 degrees C. The slopes of the rate temperature curves were similar for all species (Q(10)s of 2.14-2.84), although the intercepts differed significantly in the direction (warm arid to cool mesic): S. gariepinus