Effects of Hexaflumuron on fecundity, fertility and longevity of Ephestia kuehniella Zeller and Spodoptera exigua (Hübner)

Resumen

The effect of hexaflumuron on number of eggs laid, egg hatch and adult longevity through treatments of adults of Ephestia kuehniella and Spodoptera exigua has been evaluated. When adults fed hexaflumuron-treated water along their life span (doses ranging from 1 to 1000 microg/ml in E. kuehniella and from 1 to 104.86 microg/ml in S. exigua), fecundity was reduced in a dependent dose manner in both species. The product was far more effective against the noctuid. The efficacy in the reduction of fecundity was 63 percent for a dose of 100 microg/ml in S. exigua and 100 percent for a dose of 1000 microg/ml in E. kuehniella. A lack of ovicidal effect was observed in S. exigua, and an average of around 50 percent of eggs hatched. In E. kuehniella however, the average percentage hatch of eggs of untreated females was 65 percent, while reductions higher than 85 percent were scored from 270 microg/ml onwards. Longevity was also significantly reduced in both lepidopterous pests. Mortality data when half life span of every species had elapsed (7 days for E. kuehniella and 5 days for S. exigua) could be represented by probit-log dose lines of slopes 2.99+/-0.53 and 9.91+/-3.23 respectively. The LD50's and 95 percent fiducial limits were 104.8 microg/ml (213.2; 468.0) for E. kuehniella, and 382.9 microg/ml (451.7; 824.3) for S. exigua.