INTRA-SPECIFIC COMPETITION AND CANNIBALISM IN THE LADYBIRD BEETLE, Coccinella undecimpunctata L. (COLEOPTERA: COCCINELLIDAE)

Document Type : Original Article

Author

Plant Protection Dept., Fac. of Agric., Al-Azhar University, Cairo, Egypt

Abstract

Investigation of the intra-specific competition of different developmental stages of Coccinella undecimpunctata L. was done on scarcity of food and different diet combinations. There was indiscriminate egg cannibalism among the larvae and adults of their own species. The scarcity of food was not the only reason for cannibalism. The fourth instar larvae were more voracious while feeding on eggs as well as on the first instar larvae as compared with the other three larval instars. The increasing numbers of egg consumption by adults was also related to their egg production and the length of the oviposition period. It is concluded that cannibalism increased the survivorship and shortened the developmental period of C. undecimpunctata.