Parasitoeds (Hym.: Aphelinidae) of three scale insects (Hom.: Diaspididae) in a citrus grove in valencia, spain

Abstract

The parasitoids ofAonidiella aurantii (Maskell),Lepidosaphes beckii (Newman) andParlatoria pergandii Comstock were studied in a Navel orange grove in Valencia, Spain during three years. Four species ofAphytis were identified on yellow sticky traps,Aphytis chrysomphali (Mercet),Aphytis melinus Debach,Aphytis lepidosaphes Compere andAphytis hispanicus (Mercet). No consistent annual pattern was observed in the flight of adults.A. melinus, introduced some years earlier in the grove, was found in very low numbers and showed no signs of increasing and displacingA. chrysomphali as a parasitoid ofA. aurantii. On female scales of the three species sampled at regular intervals from leaves, twigs and fruit, the mean annual rate of active parasitism was similar and ranged from 3.5% to 8%.P. pergandii males were not parasitized, inL. beckii parasitism was usually much lower in male than in female scales, and inA. aurantii it was higher in the males. Scales of the three species were less parasitized on twigs than on leaves, and so wereL. beckii on fruit. The annual trend of parasitism byAphytis on scales fluctuated without a definite pattern. Parasitism byEncarsia inquirenda (Silvestri), an endoparasitoid ofP. pergandii, was more stable throughout the year and increased steadily from year to year.