Contact toxicity of 5 alien plant extracts on Macrosiphum rosivorum.
By using 95% ethyl alcohol, stems and leaves extract from Eupatorium adenophorum, Mikania micrantha, Bidens pilosa, Tithonia diversifolfa, Oxalis corniculata were extracted. Every kind of extract was diluted to 3 concentrations of 1, 5 and 10 times. The bioassays of contact toxicity on M. rosivorum were tested by microdrip at 24 h, 48 h and 72 h in laboratory. The results indicated that the contact toxicity on Eupatorium adenophorum, Mikania micrantha apparently higher than the others, contact toxicity of the five plant extracts showed no significant difference in different concentration, contact toxicity of Tithonia diversifolfa showed extremely significant difference in different time, and the other 4 invasive plants showed significant difference.