The effective natural enemies on pests in olive groves of Bursa (Turkey) and the population fluctuations of important species

Abstract

A survey of the predatory and parasitoid fauna of olive pests, including Prays oleae (Bern.), Bactrocera oleae (Gmelin.), Palpita unionalis (Hübn.) and Saissetia oleae Bern., was undertaken during April-November 2000-2002 in Bursa, Turkey. The important species were monitored using sweep nets, sticky traps and knocking. According to the results of this study, a total of 20 species of natural enemies was found in 26 olive groves. In addition, Chrysopa cornea (Stephens) and Scymnus rubromaculatus (Goeze) were determined as the most active predator of olives and their population fluctuations were monitored in 2000-2002. Adults of C. carnea appeared from early May to mid December, reaching peaks in August and November in 2002. Of the coccinellid predators, S. rubromaculatus was present during early August-early November and reached 3-4 peaks around early August, mid September and early November in 2000 and 2002. Parasitism rates of Scutellista cyanea Motsch, an ectoparasitoid of S. oleae, were very high at unspraying olive groves, while the parasitism was not observed at spraying orchards.