Biocontrol of Sassetia coffeae by augmentation, releasing and evaluation of Scutellista caerulea in Egypt

The aim of this study was to evaluate the biological control potential of Scutellista caerulea (Fonscolombe)) (Hymenoptera: Pteromalidae) against the hemispherical scale, Saissetia coffeae (Walker) (Hemiptera: Coccidae) on olive (Olea europaea L.) by mass rearing and augmentative releases of this natural enemy during a long-term field study in Egypt. A study was conducted to evaluate biocontrol potential of this pest by augmentation with a parasitoid, S. caerulea. This species was mass reared and monthly releases were made in fields of olive during each of 11 consecutive years (2001-2011). About 339045 and 337650 S. caerulea were released in fields in El-Arish and Northern Coast locations in Egypt on olive which was naturally infested by S. coffeae. Populations of the natural enemy and parasitism were much higher in field plots where releases were made as compared with where no releases were made. The maximum rate of parasitism reached 87.5% (84.5% by S. caerulea) in the field treatment where releases were made, while parasitism peaked at 46.2 % where no releases were made. The population of S. caerulea was significantly correlated with the population the whitefly during the field season. Additional parasitism was by natural infestations by Rates of parasitism of by Coccophagus scutellaris (Dalman) (Hymenoptera: Aphelinidae), Microterys flavus (Howard) in El-Arish and Metaphycus helvolus (Compere) and M. lounsburyi (Howard) in Northern Coast (Hymenoptera: Encyrtidae). These observations enhance the understanding of the usefulness of this natural enemy after augmentation in the field.

Keywords:

Biocontrol , Parasitic hymenoptera , Scutellista caerulea , Soft scale insects