Genetic variation in host discrimination ability in Diachasmimorpha longicaudata (Hymenoptera: Braconidae) attacking Ceratitis capitata (Diptera: Tephritidae).

F DEVESCOVI; NUSSENBAUM; BACHMANN GUILLERMO; LANZAVECCHIA; CLADERA; SEGURA

Conferencia; 4th International Entomophagous Insect Conference; 2015

The solitary endoparasitoid D. longicaudata incurs in superparasitism (SP) when mass-reared for fruit fly pest control. SP can negatively affect the quality and quantity of emerged adults. Females avoiding parasitized hosts (i.e. host discrimination ability) could be selected to obtain a more efficient strain. We studied the genetic variability and heritability in the host discrimination ability of D. longicaudata attacking C. capitataA group of host larvae were exposed to a single, virgin parasitoid female (parental F0) (Fig. 1). 50 females were tested. Through indirect methods, the discrimination ability of each F0 female was assessed: the number of parasitoid larvae per host was obtained by dissection, and the distribution of eggs was compared to a Poisson distribution (i.e. random).12 virgin F0 females were selected, representing a continuum in the behavioral trait, from non discrimination to complete discrimination. By means of backcrosses with their respective sons, isofemale lines were founded (Fig. 2). Each of 4-8 F1 females were tested as F0 females. The mean number of eggs/host (λ) and the Poisson dispersion index (variance/λ) were further analyzed.Host discrimination ability showed to be variable among females.However, this phenotypic variation could not be explained by a genetic basis.A higher number of Isofemales lines and daughters, together with the evaluation of later generations could allow a better evaluation of the genetic basis of the SP acceptance/rejection behavior.