KFIR, R., Hebrew University, Faculty of Agriculture, Rehovot, Israel
PODOLER, H., Hebrew University, Faculty of Agriculture, Rehovot, Israel
ROSEN, D., Hebrew University, Faculty of Agriculture, Rehovot, Israel

Two hyperparasites, Cheiloneurus paralia (Walker) and Marietta exitiosa Compere, of Microterys flavus (Howard), a primary parasite of the brown soft scale Coccus hesperidum L. have been studied. The area of discovery of the hyperparasites for secondary hosts (scale insects) is greater than that of the primary parasite, indicating higher searching efficiency of the secondary parasites. Cheiloneurus has a higher searching efficiency measured as its area of discovery for discovering both the secondary (scale insect) and the primary (Microterys) hosts, as compared with Marietta. The searching efficiency of Cheiloneurus increased in the presence of its own males. In each species there is a non‐linear relationship between the searching efficiency and female density. Cheiloneurus and Marietta present two differing searching strategies. Cheiloneurus tends to exploit as many primary hosts as possible in each secondary host encountered, whereas Marietta, tends to disperse its progeny more regularly by avoiding, to a certain extent, the exploitation of more than one host in each scale insect encountered. Copyright © 1976, Wiley Blackwell. All rights reserved