Ecological data on predators ofParlatoria pergandii on sour orange trees in southern Greece

Abstract

The present study was carried out in southern Greece during 1993-1995 on sour orange trees infested with the diaspididParlatoria pergandii Comstock. The activity of the natural enemies of the scale, the composition of their population during the year as well as their relation with hymenopterous parasitoids of coccinellids, were studied.P. pergandii was parasitized by a hymenopterous endoparasite of the genusEncarsia and the extent of parasitization ranged between 5.2% and 14.1%. The observed predators were the coccinelidsChilocoms bipustulatus Linnaeus andRhyzobius lophanthae Blaisdell and the nitidulidCybocephalus fodori Endrödy-Younga. The predominant predator wasR. lophanthae (84.3% of the larvae and 73.3% of the adults), which was active throughout the whole year in all of its developmental stages. Second most abundant was the predatorC. bipustulatus (15.7% of the larvae and 20% of the adults) and third the predator C.fodori (6.7% of the adults). Larvae ofC. bipustulatus were observed to be parasitized by the hymenopterous parasitoidsHomalotylus flaminius Dalman (Encyrtidae) andTetrastichus coccinellae Kurdjumov (Eulophidae). The parasitization percentage increased gradually from 4% in mid June to 94% around the end of September. Laboratory tests confirmed that the above mentioned parasitoids cannot infest larvae or nymphs ofR. lophanthae.