Status and importance ofRhyzobius forestieri (Col.: Coccinellidae) on citrus at chios Island, Greece, nine years after its introduction

The originally Australian coccidophagous predatorRhyzobius forestieri (Coleoptera: Coccinellidae), imported from California into Greece in 1981, was first released on citrus at Cambos, Chios, in 1983 against soft scalesCoccus pseudomagnoliarum andSaissetia oleae (Homoptera: Coccidae). It was successfully established in two orchards there. During the following decade,R. forestieri spontaneously dispersed throughout the Cambos coastal plain. In July 1992, a survey of coccidophagous coccinellids was carried out, to follow up on the dispersal ofR. forestieri on citrus and to compare its population size with that of the main native coccidophagous coccinellids. The samplings were made in 4 selected scale-infested orchards of Cambos spaced 1–2 km apart. Of a total of 337 adults and 237 larvae of coccidophagous coccinellids found,R. forestieri comprised 84.0% and 75.1%, respectively. It was present in all 4 localities; in 2,R. forestieri adults and larvae were by far the most abundant coccidophagous coccinellids.