Interspecific interaction between Anagyrus fusciventris and Tetracnemoidea brevicornis for controlling Pseudococcus calceolariae

Abstract

ABSTRACT Anagyrus fusciventris and Tetracnemoidea brevicornis (Hymenoptera: Encyrtidae) are solitary endoparasitoids of Pseudococcus calceolariae and P. longispinus (Hemiptera: Pseudococcidae), major pests of many horticultural crops. The interspecific interaction relate to host-parasitoid association between these two parasitoid species was tested in the laboratory. To test the hypothesis that both species prefer the same life stages of P. calceolariae, first instar to adult mealybugs were exposed to female parasitoids of both species for either 24 h or 10 days. The parasitism by each parasitoid species of eggs and newly emerged or late first instar P. calceolariae was individually tested. A sequential test was also carried out, where mealybugs were exposed to either of the two parasitoid species with 24-h intervals between the exposure to the first and second parasitoid species. Regardless of the time or order of exposure, T. brevicornis females produced a larger proportion of parasitoid progeny within their short adult lifespan (< 10 days). The maximum daily reproductive output of T. brevicornis (32) was higher than A. fusciventris (8). Egg to adult development period of A. fusciventris was shorter (20 ± 1.6 (SD) days) than T. brevicornis (36.6 ± 4.6 (SD) days). A complementary effect of the two species on mealybug suppression was highlighted in our findings, due to their species-specific host stage preference, A. fusciventris prefer older life stages while T. brevicornis prefer younger life stages. Therefore both species together could provide stable control of the pest population more effectively than one species alone.