Effects of conventional insecticides and insect growth regulators on fecundity and other life-table parameters of Micromus tasmaniae (Neuroptera: Hemerobiidae)

Effects of 3 conventional insecticides (methyl parathion, azinphos-methyl, cypermethrin) and 3 insect growth regulators (fenoxycarb, diflubenzuron, and tebufenozide) on life-table parameters of Micromus tasmaniae Walker were determined in adults derived from insecticide-treated larvae. The following parameters were compared with the control: sex ratio, longevity, sterility, and fecundity. Power analysis was used to increase the efficiency and the predictability of the life-table test. Diflubenzuron resulted in a higher proportion female lacewings. Longevity was reduced for females emerging from fenoxycarb- and diflubenzuron-treated larvae. Total number of eggs was reduced for diflubenzuron- and fenoxycarb-treated lacewings, as well as the following generation of tebufenozide-exposed lacewings. Daily number of eggs was reduced for the diflubenzuron treatment. Peak egg production was increased for lacewings exposed to azinphos-methyl and was decreased for the following generation of tebufenozide-exposed lacewings. Diflubenzuron treatment resulted in an extended preoviposition period. Oviposition periods were reduced for lacewings treated with fenoxycarb, diflubenzuron or azinphos-methyl as well as for the following generation of the tebufenozide treatment. The time to peak egg production was similar for all treatments. Methyl parathion, cypermethrin, and tebufenozide treatments showed no differences in any of the tested life-table parameters in the Ist generation. In summary, the insect growth regulators fenoxycarb and diflubenzuron had a more severe impact on life-table parameters than the 2 organophosphates and the pyrethroid. In future research, increased attention should be paid to long-term (e.g., the following generation) effects on life-table parameters.