Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Studies on Aspidiotus destructor Sign.(Hem.:Diaspididae) and its parasites, Aphytis melinus DeBach (Hym.:Aphelinidae) and Pakencyrtus pakistanensis Ahmad. (Hym.: Encyrtidae) in Pakistan.

Abstract

Aspidiotus destructor Sign. is a serious pest of mango and coconut in Pakistan. Heavy infestations have been observed every year, usually during August-December, at several localities in the former Pubjab and Sind Provinces, and studies showed that the pest was common in the coastal and sub-coastal areas. Information is given on the bionomics of the Coccid, and the rearing methods used in the laboratory are described. Fruits of Cucurbita maxima were used as food. Females laid 71-148 (average 113) eggs each, and the total development from oviposition to the adult stage averaged 33.9 days for males and 27 days for females. During field studies, Aphytis melinus DeBach was found to be an important parasite of this species and also of Aonidiella (Aspidiotus) aurantii (Mask.), A. (A). citrina (Coq.) and A. (A.) orientalis (Newst.). It attacked up to 37% of Aspidiotus destructor on mango. The host was attacked at both high and low densities, and the parasite was found to occur throughout Pakistan. When it was reared in the laboratory, females laid 25-49 (average 34) eggs each, and development from ovipostion to adult emergence averaged 17.7 days. The most abundant parasite of A. destructor was Pakencyrtus pakistanensis Ahmad [RAE/A 60, 2704]; parasitism reached 42%. In the laboratory, females laid 19-52 (average 36) eggs each, and development from egg to adult was completed in an average of 14 days. It is considered that both parasites are of potential value for introduction into areas where A. destructor is a pest.