Effect of Eupatorium adenophorum Spreng leaf extracts on the mustard aphid, Lipaphis erysimi Kalt: a scanning electron microscope study.

Scanning electron microscopic study revealed some remarkable adverse effects of Eupatorium adenophorum Spreng leaf extract on cuticular and antennal sensilla of the mustard aphid, Lipaphis erysimi Kalt. The study appears to be the first of its kind in providing evidence on toxic property of the plant on certain agricultural pests, although the indigenous tribes of the region know the insecticidal property of the plant for a long time. The study further provides indications regarding the neurotoxic nature of the leaf extract since it has caused abnormalities in the sensory structures. The presence of prominent swellings in some sensilla and shrinkage in others suggests that the leaf extract affects different systems through different mechanisms. The possible use of the plant as a potential biopesticide against certain insect pests is discussed. Copyright 2005 Wiley-Liss, Inc.