Environmental degradation of the insect growth regulator methoprene

Juvenile hormone induces queen development in late-stage larvae of the ant Harpegnathos saltator

“…It is likely that even lower doses of JHA would have induced queen development in third and fourth instar larvae if biting were absent, but we could not dissociate biting from our treatments since workers were needed to care for developing larvae. A small portion of first and second instar larvae did developed as queens in our trials, but this may be due to the fact that JHA is more stable than natural JH-III and can persist inside the body for an extended period of time (Bigley and Vinson, 1979;Quistad et al, 1975). It is likely that residual JHA may have affected queen development of first and second instar larvae if it was still present in later instars.…”

“…Methoprene degrades at a slower rate compared to natural JH-III and can remain biologically active over a longer duration (Bigley and Vinson, 1979;Quistad et al, 1975). We established 2 satellite nests for each of 10 stock colonies.…”

Efficacy of Broadcast and Perimeter Applications of S-Methoprene Bait on the Red Imported Fire Ant in Grazed Pastures

“…Experiments with methoprene residue under heat and UV light indicated that photolysis was the most signiÞcant mechanism of environmental degradation (Quistad et al 1975). Similar studies with Amdro (hydramethylnon) Þre ant bait have shown that UV light quickly degrades the active ingredient, suggesting that evening applications may be more effective than daytime applications (Vander Meer et al 1982).…”

“…The efÞcacy of methoprene bait at site 2 also may have been compromised by high temperatures combined with sunny conditions (Schaefer and Dupras 1973, Gill et al 1974, Mulla and Darwazeh 1975, Norland and Mulla 1975, Quistad et al 1975. Experiments with methoprene residue under heat and UV light indicated that photolysis was the most signiÞcant mechanism of environmental degradation (Quistad et al 1975).…”

“…revealed that nearest colonies could simultaneously forage along a territory boundary, but resource discovery in that area was signiÞcantly slower than other territorial regions (Ryti and Case 1986). Such time lags could increase exposure of methoprene to degradative effects of heat and sunlight (Quistad et al 1975).…”