ATTRACTIVENESS OF DUNG FROM IVERMECTIN-TREATED CATTLE TO DANISH AND AFROTROPICAL SCARABAEID DUNG BEETLES

The effect of ivermectin treatment of cattle on the attractiveness of dung to scarabaeid dung beetles was assessed by pitfall trapping in De nmark, Tanzania and Zimbabwe. Traps were baited with dung collected at intervals after heifers were treated with ivermectin by subcutaneous injection (0.2 mg kg-1 body weight). In one Danish trial, beetles pref erred control dung from untreated cattle, whereas no preference was fo und in two other experiments. In Tanzania, the overall tendency for be etles was also to prefer control dung. In Zimbabwe, two species (Euoni ticellus intermedius and Liatongus militaris) were particularly attrac ted to dung from treated cattle, whereas three others did not discrimi nate between dung types. It is concluded that at least in some cases t he attractiveness of cattle dung to scarabaeid beetles is affected by avermectin therapy. Beetle discrimination between dung types is probab ly attributable to some unknown side effect of the treatment rather th an being a direct response to the drug itself.