Exploration of natural enemies of calotrope in its native range: predispersal seed-predation in Pakistan

Abstract

This paper presents the results of life history, seasonal dynamics and damage potential of Aak fruit fly (Dacus persicus) and Aak weevil (Paramecops farinosus) on Calotropis procera under laboratory and field conditions in Lahore, Pakistan. Populations of D. persicus began to increase in summer (June) and peaked in August-September before starting to decline in autumn (November). The duration of the life cycle of D. persicus (egg to adult) was 42.2 ± 0.4 days (mean ± SE) with a range of 38-50 days. The average life span of an adult fly was 16.4 ± 0.7 days. The Aak fruit fly larvae destroyed all immature seeds and internal tissue of infested pods of the host plant. In contrast, Aak weevil populations built slowly during spring and early summer (March-May) and peaked in late summer (August). Like the Aak fruit fly, the larvae of the Aak weevil also destroyed all immature seeds of infested pods. Field host specificity, fast development and damage potential of the fruit fly and weevil indicate that these agents hold promise to be considered as potential candidate agents for biological control of C. procera in Australia and other parts of the world where C. procera and the closely related C. gigantea are problem weeds. Both agents are planned to be imported into quarantine for further testing in Australia.