EFFECTS OF POPULATION DENSITIES OF BLACK BEAN NYMPH ON BIOLOGICAL PERFORMANCE OF THE PREDATOR LARVAE OF COCCINELLA SEPTEMPUNCTATA L. | ||
| The Iraqi Journal of Agricultural Science | ||
| Article 1, Volume 43, Issue 2, June 2013, Pages 18-27 | ||
| Author | ||
| J. K. Al-Rubeae | ||
| Abstract | ||
| The Coccinella septempunctata L. is one of the important control agents against many economic insects. The aim of this research was to study the biological concepts which help in the continuation of predation . Results indicated that was a positive correlation between predator efficiency and aphid density , the lowest consumption of nymph of Aphis fabae(Scopoli) was 4.34 nymph/day when prey density was 5 nymphs/day , while consumption was increased to 20.62 nymph/day when prey density were 30 nymph/day. And The period for development of predator larvae and percentage of mortality correlated negatively with density of aphis nymph . The shortest period was 13.39 days at a density of 30 nymph / day with no observed mortality . However, The period of development was increased to 25.63 days with 40% mortality at 5 nymph/day. Curves of the functional response showed that the larva of the predator is of a second type ( cyrtoid ) of the functional response . The rate of attack coefficient was increased while the handling time was reduced , the highest attack coefficient was 1.003 cages for the 4th larval stage and the lowest attack rate was 0.875 cages for 1st larval stage. However, the highest handling time was 56.16 minutes for the 1st larva stage and the lowest handling time was 5.67 minutes for the 4th larval stage . It was concluded that predator efficiency was directly correlated with the population density of aphids nymph . Therefore using 20 nymph /day the aphids to rear the Coccinella septempunctata L. | ||
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