Development and morphological characterization of the immature stages of Tetrastichus giffardianus Silvestri (Hymenoptera: Eulophidae)

ABSTRACT

ABSTRACT The gregarious endoparasitoid Tetrastichus giffardianus Silvestri (Hymenoptera Eulophidae) is a natural enemy of fruit flies. This parasitoid was previously used to successfully control Ceratitis capitata (Wiedemann) (Diptera Tephritidae) in Hawaii, USA. Despite its importance in the control of fruit fly pests, little is known about the development or characteristics of its preimaginal stages. The aim of this study was to observe the development and morphologically characterize the immature stages of Tetrastichus giffardianus. Tetrastichus giffardianus individuals were reared on C. capitata larvae/pupae under laboratory conditions at a temperature of 25 ± 2 °C, relative humidity of 60 ± 10%, and 12-h photophase. Third-instar C. capitata larvae were exposed to parasitism for 24 h. After parasitism, the pupae were dissected every 24 h to evaluate the stage of development attained by T. giffardianus, and to record their morphological characteristics. A stereomicroscope was used to observe all the immature stages of T. giffardianus. The complete development of T. giffardianus under these conditions was completed within 14 days as follows egg (duration ≅ 1 day); first (≅ 1 day), second (≅ 1 day), and third (≅ 2 days) larval instars; pre-pupa (≅ 2 days); and pupa (≅ 7 days). The immature stages of T. giffardianus differed sufficiently in their shape, color, and size to allow morphological characterization.