Studies on the ectoparasitoid, Anisopteromalus calandrae How. (hymenoptera: pteromalidae) as a biocontrol agent against the lesser grain borer, Rhyzopertha dominica (Fab.) in Saudi arabia

Abstract

Anisopteromalus calandrae How. was reared in the laboratory on full grown larvae of Rhyzopertha dominica (Fab.). The incubation period of the parasitoid's egg was 36 h at 26°C and 27 h at 30°C. The larval stage lasted 6.9 and 5.4 days, the prepupal stage lasted 23.6 and 17.8 h, and the pupa lasted 5.4 and 4.6 days at 26 and 30°C, respectively. The total developmental time (from egg to adult) averaged 18.9 and 14.6 days at 26 and 30°C, respectively. Sex ratio was 2.1♀:1♂ in the field and 2.3♀:1♂ in the laboratory. The daily and total numbers of eggs laid/female were 6.7, 150.4 and 8.3, 132.6 at 26 and 30°C, respectively. The parasite female and male, fed on honey, lived for 32.6 and 25.5 days at 26°C, respectively. Percentages of parasitism recorded in the laboratory were, respectively 69.5, 43.3, 30.1, 16.8 and 0 on R. domenica, Sitophilus granarius, Bruchus rufimanus, Trogoderma granarium and Oryzaephilus surinamensis. The parasitoid was active in the field from February to November, but reached its peak in July with a 59.3% parasitism on R. dominica.