Influences of larval instars and food of Spodoptera frugiperda larvae on parasitism of Microplitis palidpes.
Effects of larval instars and food of Spodoptera frugiperda larvae on the parasitism of Microplitis palidpes on S. frugiperda larvae were investigated under the laboratory conditions. The results showed that, regardless of the food (artificial diet or corn leaves) of S. frugiperda larvae, the parasitism rate, cocooning rate, parasitoid emergence rate, and mortality rate of host larvae were significantly higher when the wasps parasitized on 3- and 5-day-old host larvae than when on 8-day-old host larvae. In addition, under the same host larval instars, the parasitism rate, cocooning rate and parasitoid emergence rate of the wasps parasitizing larvae fed corn leaves were higher than those of the wasps parasitizing larvae fed artificial diet. In general, host larval food influenced the parasitism of M. palidpes on the 5-day old S. frugiperda larvae, which was better than the parasitism on the other two host larval instars. The results can provide a theoretical basis for the use of S. frugiperda larvae to multiply M. palidpes in the insectary and the field application of M. palidpes to control of S. frugiperda.