Emm. Gardiner et Fw. Plapp, INSECTICIDE UPTAKE AND DECREASED UPTAKE RESISTANCE IN THE HOUSE-FLY (DIPTERA, MUSCIDAE) - A STUDY WITH AVERMECTIN, Journal of economic entomology, 90(2), 1997, pp. 261-266
We examined the pharmacokinetics of insecticide uptake and decreased u
ptake resistance to insecticides in the house fly Musca domestica, L.
Flies were briefly exposed to low (2 ng) or high (200 ng) residues of
[H-3]avermectin in glass vials and then transferred to clean vials. Ad
sorption occurred within 2 min and to a similar extent in susceptible
and resistant flies. After transferring exposed flies to clean vials,
much of the adsorbed avermectin was lost within 15 min and the loss wa
s greater in resistant flies. In contrast, uptake of avermectin into t
he hemolymph was more extensive in susceptible flies. Preexposing flie
s to dinitrophenol blocked avermectin uptake and loss in both strains,
suggesting avermectin transport may be facilitated by an adenosine tr
iphosphate-dependent protein. When fasted flies were fed [C-14]glucose
followed by exposure to avermectin, transport of [C-14]labeled deriva
tives of glucose to the cuticular surface was decreased relative to co
ntrols in both strains. These results suggest that the natural functio
n of a protein that facilitates insecticide uptake is to transport hyd
rocarbons from the insect hemolymph to the cuticle and that quantitati
ve or qualitative changes in the protein may relate to decreased uptak
e resistance.