Evaluation of the indigenous parasitoid Encarsia transvena (Hymenoptera: Aphelinidae) for biological control of the whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) in greenhouses in India

Abstract

The efficiency of the native parasitoid, Encarsia transvena Timberlake for the management of greenhouse whitefly, Bemisia tabaci (Gennadius) was studied in cages and a greenhouse in India. Parasitism by Enc. transvena of B. tabaci on Lycopersicon esculentum L. (tomato), Solanum melongena L. (eggplant) and Nicotiana tabacum L. (tobacco) was evaluated in cages to compare the utility of each species as potential banker plants. B. tabaci populations were consistently present on all three host plant species for almost two months providing sufficient hosts for parasitoid multiplication. Significantly more B. tabaci nymphs/unit leaf area were found on N. tabacum (77.7) and on S. melongena (76.5) than L. esculentum (45.9) in the initial growing period of the plants, that increased more on L. esculentum as the crops grew older. A greater proportion of B. tabaci were parasitised by Enc. transvena on L. esculentum than on N. tabacum and S. melongena. Rate of parasitism on L. esculentum was 25.19 and on N. tabacum was 24.70 in greenhouse. Parasitism, although occurring throughout greenhouses, was greatest on plants within 3 metres of introduced banker plants. The results suggest the utility of the three plant species as potential banker plants for the management of whiteflies in greenhouses.

Keywords:

• Encarsia transvena
• Bemisia tabaci
• parasitism
• greenhouse
• banker plants

Acknowledgements

We thank Dr V. V. Ramamurthy, Insect Biosystematics, IARI, New Delhi for parasitoid identification, Dr A. Sujatha for technical support and the Director of IIHR, Bangalore for providing facilities.