A comparison of the development and survival of the dung beetle, Onthophagus taurus (Schreb.) when fed on the faeces of cattle treated with pour-on formulations of eprinomectin or moxidectin.
Faeces voided by 1-year old cattle at 3-70 days after treatment with a pour-on formulation of moxidectin had no detectable effects on development or survival of the common dung beetle Onthophagus taurus. In contrast, faeces voided by cattle treated with a pour-on formulation of eprinomectin were associated with high juvenile mortality during the first 1-2 weeks after treatment. Increased mortality also occurred among newly emerged beetles fed on faeces collected 3 days after eprinomectin treatment and there was evidence of suppressed brood production among those that survived. This effect was still apparent even after insects fed for a further 10 days on the faeces of untreated cattle. A model simulating the effects of drug residues on dung beetle populations suggests that in the absence of immigration a single treatment of eprinomectin is capable of reducing beetle activity in the next generation by 25-35%. Effects are likely to be greatest when treatment coincides with emergence of a new generation of beetles.
Wardhaugh
K G
KG
CSIRO Entomology, GPO Box 1700, Canberra, ACT 2601, Australia. keith.wardhaugh@ento.csiro.au
Longstaff
B C
BC
Morton
R
R
D000818:Animals; D000871:Anthelmintics / Q000633:toxicity*; D000900:Anti-Bacterial Agents / Q000633:toxicity; D001315:Australia; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy / Q000517:prevention & control*; D001517:Coleoptera / Q000187:drug effects / Q000254:growth & development* / Q000502:physiology; D004350:Drug Residues / Q000633:toxicity*; D005243:Feces / Q000469:parasitology*; D005260:Female; D006374:Helminthiasis, Animal / Q000188:drug therapy / Q000517:prevention & control*; D007559:Ivermectin / Q000031:analogs & derivatives / Q000633:toxicity; D018942:Macrolides; D008954:Models, Biological; D013997:Time Factors
D000871:Anthelmintics; D000900:Anti-Bacterial Agents; D018942:Macrolides; D007559:Ivermectin; C101434:eprinomectin; C027837:moxidectin