Field superparasitism by Diachasmimorpha longicaudata attacking Anastrepha spp. larvae on mango fruits

The incidence of superparasitism in field populations of Diachasmimorpha longicaudata (Ashmead), a solitary larval-pupal endoparasitoid, attacking Anastrepha fruit fly species was determined. From 14,550 fruit fly larvae infesting mango fruits in the field, 68.9% (10,038) survived to the pupal stage. Of these pupae, 3780 (37.7%) were parasitized, of which 2075 (54.9%) were superparasitized. The number of oviposition scars per pupa ranged between 1 and 29, although high numbers were rare. The presence of one or two scars per host was frequent, but only 8.6% of pupae had more than three scars. Fruit size was positively related to the level of infestation by Anastrepha spp. and was significantly correlated with the numbers of parasitized and superparasitized pupae by D. longicaudata. The length and width of host pupae were positively related to superparasitism, and superparasitism was positively correlated with a sex ratio biased toward females. Our data show that superparasitism is present in natural populations of D. longicaudata at remarkable rates and confers some advantageous features such as a female-biased sex ratio. These findings favor the election of this species as a viable biocontrol agent for augmentative releases because the favorable proportion of adult females emerging from superparasitized pupa should contribute to better pest control.

Graphical abstractSuperparasitism by Diachasmimorpha longicaudata (Hymenoptera: Braconidae), a larval-pupal fruit fly parasitoid, reached remarkable records at field levels (55% of parasitized pupa), and seems to be affected by fruit size (see annexed figure) and host larvae size. A female biased sex ratio related to superparasitism was also observed.Download full-size imageHighlights► 54.9% of attacked pupa by D. longicaudata were superparasitized. ► The number of oviposition scars per pupa ranged between 1 and 29. ► Fruit size was correlated with the numbers of parasitized and superparasitized pupae. ► Superparasitism was positively correlated with a sex ratio biased to females. ► Superparasitism seems to be a characteristic of common occurrence in D. longicaudata.