BIOLOGICAL CONTROL OF THE FRUIT TREE MEALYBUG, RASTROCOCCUS INVADENS WILLIAMS; SINGLE OR MULTIPLE INTRODUCTION?
Comparative studies were done with a second parasitoid Anagyrus mangicola, found by IIBC in India. Direct competition between the parasitoids is restricted to the second stage host. G. tebygi has more potential hosts, a more female biased sex ratio (42–47%) than A. mangicola (27–32%), and a development time, from oviposition to sexual maturity, of 27–29 days compared with 20–22 days for A. mangicola and 40–45 days for R. invadens. Both killed early stage mealybugs but only G. tebygi exhibited host-feeding. A. mangicola is more heavily attacked by indigenous hyperparasitoids. A. mangicola proved superior in competition between the larval parasitoids. There was no evidence that the introduction of A. mangicola would reduce control by G. tebygi; the former may be superior in areas where R. invadens growth is poor.
Both parasitoids have been supplied to the International Institute of Tropical Agriculture by IIBC.