Pest Management Science (2001) 57, 82-89

Michael Kristensen, Andrew G. Spencer and Jørgen B. Jespersen (2001)
The status and development of insecticide resistance in Danish populations of the housefly Musca domestica L.
Pest Management Science 57 (1), 82-89
Abstract: Samples of housefly (Musca domestica) field populations were collected from Danish livestock farms in 1997. The tolerance of the first-generation offspring was determined for a number of insecticides. Dose-response values were obtained by topical application for the pyrethroids bioresmethrin and pyrethrum, both synergised with piperonyl butoxide, and the organophosphate dimethoate. The organophosphates azamethiphos and propetamphos and the carbamate methomyl were tested in discriminating dose feeding bioassays. Resistance was low to moderate in most of the populations for most of the compounds tested, but this study also revealed the existence of high resistance to pyrethroid, organophosphate and carbamate insecticides in some populations. The resistance factors at LD₅₀ for bioresmethrin/piperonyl butoxide ranged between 2 and 98, and for pyrethrum/piperonyl butoxide between 2 and 29. Our results indicate that pyrethroid resistance in Denmark is increasing, since four of the 21 farms showed more than 100-fold resistance at LD₉₅, a level of resistance only observed once before. Resistance factors at LD₅₀ for dimethoate ranged from 9 to 100, and showed two distinct trends: populations with either decreasing or increasing resistance. Resistance to azamethiphos was found to be widespread and high. Although two strains with high methomyl and propetamphos resistance were observed, methomyl and propetamphos resistance is moderate and appears not to be increasing.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Michael Kristensen

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Musca domestica		Denmark