Abstract

                                Studies were undertaken on the diversity of predatory coccinellids in two locations of horticultural ecosystems comprising citrus, guava, mango, sapota and pomegranate in Madurai and Periyakulam of Madurai and Theni districts, respectively, in Tamil Nadu. Of ten species of predatory coccinellids recorded, the dominant coccinellid species were Chilocorus nigrita (F.), Jauvaria sp. Nephus regularis Sicard and Nephus sp. The occurence of Cheilomenes sexmaculata (F.), Scymnus castaneus Sicard, Scymnus coccivora Ayyar and Pseudaspidimerus trinotatus Thunberg were low while Chilocorus circumdatus (Gyllenhal) was the rare species. Pomegranate in Madurai and citrus and mango in Periyakulam had high species richness. Equitable distribution of species was recorded in mango in Madurai. But more species evenness was recorded in citrus, guava, sapota and pomegranate in Periyakulam. Diversity of coccinellids was high in mango and pomegranate in Madurai while in citrus, guava and sapota in Periyakulam. Simpson’s diversity values (for an individual of coccinellid taxa) were high in guava and pomegranate in Madurai, while in citrus, mango and sapota in Periyakulam. This study suggests that the diversity of coccinellid depends on the associated prey insects and more particularly to the locality. Hence, a complete data sheet on the diversity of the coccinellids is warranted on crops in association with prey insects to know the dominant species, which may be conserved or released for efficient biosuppression of pest insects

Key words : Diversity, coccinellids, citrus, guava, mango, sapota, pomegranate