Rearing technique and demographic parameters of Tetrastichus giffardianus Silvestre (Hymenoptera: Eulophidae)

Abstract

Tetrastichus giffardianus Silvestri (Hymenoptera: Eulophidae) is a gregarious koinobiont endoparasitoid of frugivorous dipterans. In recent years, T. giffardianus has been detected parasitizing Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in different Brazilian semiarid sites. Thus, T. giffardianus has potential to be used in the biological control of C. capitata in semi-arid conditions. However, one of the factors limiting the use of this parasitoid is the lack of detailed information on rearing methods and bioecological aspects. Therefore, the main objectives of this study were to demonstrate a rearing technique for T. giffardianus and to determine the increase in population under laboratory conditions. Specimens of T. giffardianus were obtained in the field through of the collection of fruits infested with C. capitata. The specimens obtained were used to adapt a rearing methodology for T. giffardianus under laboratory conditions. Information on demographic parameters for a T. giffardianus population was obtained using the same methodology. Based on the parameters evaluated, we found that the intrinsic rate of population increase of T. giffardianus was 0.34, the average time of one generation was 19.7 days, the population doubling time was 2.03 days and the finite rate of population increase (?) was 1.41. The demographic parameters obtained demonstrated that, with the rearing technique used, it is possible to maintain populations of T. giffardianus and enable them to multiply under laboratory conditions.