Effects of methoprene and permethrin on paedogenetic larvae of Heteropeza pygmaea and Mycophila speyeri (Diptera : Cecidomyiidae)

The effects of methoprene and permethrin on larvae of Heteropeza pygmaca Wi nnertz and Mycophila speyeri (Barnes), two Cecidomyiid species of paedogene tic insect mushroom pest, were investigated in sterile culture at concentra tions of 0.1-100 mu g/g. The two highest concentrations of permethrin cause d complete mortality of M. speyeri but only low mortality of H. pygmaca. Th e main sublethal effects of permethrin on both species were reduced fecundi ty and reduced mother-larval width. Methoprene had only sublethal effects o n both species. At all doses, methoprene caused an increase in H. pygmaca g eneration time but a reduction in hemipupal width and fecundity according t o dosage. The effects on M. speyeri were similar but more severe.