Abstracts
EGG COLONIZATION OF CHRYSOPERLA CARNEA STEPH. AND ITS EFFECT ON APHID POPULATIONS ON APPLE TREES |
A. M. A. IBRAHIM, S. A. EL-ARNAOUTY, K. T. AWADALLAH and M.D. ABDALLAH Biological Control Laboratory, Fac. Agric., Cairo Univ., Cairo, Egypt |
ABSTRACT Chrysoperla carnea Steph. was reared in the laboratory to obtain a sufficient quantity of eggs for colonization. 95% and 90% of the released eggs hatched during the seasons of 1992 and 1993, respectively. In the first season, the predator/aphid ratio before colonization was 1:10.4 opposed to the ratio of 1:6.8 after colonization. In the second season, the corresponding figures were 1:8.4 and 1:5.5. Consequently, it appeared that the predator built up itself up and succeeded to decrease the aphid population. The percent of reduction in the two seasons reached to 51.8 and 16.6%. |
Key Words: Chrysoperla carnea, Colonization, Aphids, Apple-tree |