POPULATION DYNAMICS OF APHIS CRACCIVORA KOCH , LIRIOMYZA TRIFOLII (BURGESS) AND THE ASSOCIATED PREDATORS ON FABA BEAN PLANTS

Abstract

Two field experiments were carried out in Qaliobia and Kafr EL-Sheikh governorates during 2014/2015 season to study the population dynamics of Aphis craccivora Koch , Liriomyza trifolii (Burgess) infesting faba bean plants and the role of the associated predators on the population changes in the tested pests. Broad bean plants were cultivated , weekly leaf samples were collected and examined in the laboratory by a dissecting stereomicroscope as well as the numbers of the three predators: Coccinella undecimpunctata L., Chrysopela carnea (Stephs), and Orius albidipennis (Reut.) were recorded. The obtained results showed that the overall relative abundance of Aphis craccivora and Liriomyza trifolii were 26 and 74 % , respectively at Kafr EL-Sheikh governorate , and were 50% , 34 %, 18% for C. undecimpunctata, C. carnea, O. albidipennis, respectively. As for Qaliobia governorate the overall relative density of Aphis craccivora and Liriomyza trifolii were 48.5 % and 51.5 % , respectively, and were 35.5 % , 37 %, 30 % for C. undecimpunctata, C. carnea, O. albidipennis, respectively. Results also indicated that the three predators reduced the population numbers of A.craccivora and L. trifolii by 36 % and 12 % , respectively. The obtained results showed that C. undecimpunctata was the most active predator against both tested pests .