Impacts of Parasitism on the Survivorship and Reproduction of the Madeira Mealybug (Hemiptera: Pseudococcidae)

Abstract

This study was conducted to assess the impacts of parasitism by Anagyrus sp. nov. nr. sinope Noyes and Menezes on the reproductive potential and the survivorship of the Madeira mealybug, Phenacoccus madeirensis Green. The reproductive responses of P. madeirensis to parasitism were dependent upon the reproductive status of the adult mealybugs. The reproductive period and fecundity of parasitized preovipositing adult mealybugs were significantly lower (4 d and 290 eggs, respectively) than those of the unparasitized individuals (8 d and 380 eggs, respectively). However, the reproductive longevity and fecundity were not different between the parasitized and unparasitized ovipositing mealybugs. Destructive feeding by parasitoid larvae reduced the total longevity of all adult mealybugs by 1–4 d. The parasitoid only host fed on 2.4% of the 1st-instar mealybugs and none in other developmental stages. In the 4 developmental stages examined (1st, 2nd and 3rd nymphal instars, and prereproductive adult), only the survival rate of 1st-instar nymphs was significantly reduced by ovipositor insertion (97% of the unparasitized versus 88% of the parasitized). After accounting for the mortality due to host feeding and ovipositor insertion, the parasitism rate of P. madeirensis by Anagyrus sp. nov. nr. sinope was estimated at 30%.