Notes on the distribution and biology of Pediobius furvus (Gah.) (Hym., Eulophidae), a parasite of graminaceous stem-borers

Abstract

Pediobius furvus (Gah.) (Eulophidae) is a parasite of the pupae of Pyralid and Noctuid stem-borers on graminaceous crops in Africa between 17°N and 17°S. It co-exists with the other pupal parasites Dentichasmias busseolae Heinr. and Procerochasmias nigromaculatus (Cam.) (Ichneumonidae) and Hyperchalcidia soudanensis Steffan (Chalcididae), but it is more abundant below 4000 ft where P. nigromaculatus does not occur. Mating follows a courtship dance, and oviposition occurs in any part of the host pupa. The life-cycle is completed in 18–20 days at 30°C, and up to several hundred adults may emerge from a single host pupa, the most suitable pupae being 2–3 days old at the time of oviposition. Longevity was improved when sucrose was provided as food. Host pupae outside the stem were parasitised, but puparia of Diptera and cocoons of Apanteles sesamiae Cam. (Braconidae) were not parasitised in the laboratory. Pupae formed inside cocoons were not attacked. Pediobius furvus has become established in Madagascar on Sesamia calamistis Hmps, and is considered promising for biological control of graminaceous stem-borers in other countries.