Abstract:
Aprostocetus {Tetrastichus) hagenowii (Ratzeburg), an oothecal parasitoid of the American cockroach,
Periplaneta americana (L.) was released into experimental cartons to determine its potential as a biological
control agent. The parasitoids were released into experimental cartons during March-June and JuSy-
October periods. Approximately 600 adult parasitoids of mixed sex were released three times per week.
Percent parasitism of viable oothecae were 85.93% in March-June and 91.63% in July-October periods
after 7 weeks of release. After 8-11 weeks when F, generation of the parasitoid was emerging, the percent
parasitism was 89.29% in March-June and 96.51% in July-October whereas after weeks 12-17, parasitism
was 87.5 and 94.52% respectively. A. hagenowii also showed a male : female sex-ratio of 1.4:1 during both
periods.
