Abstract
Parthenium hysterophorus L., a native of tropical America, is rapidly spreading in Pakistan and replacing the local flora. Among the various causes of its rapid spread in the country, lack of natural enemies of this weed is perhaps the most important one. There is not any earlier report of fungal or bacterial pathogen, or insect pest of this weed from Pakistan. During field surveys of different Parthenium growing areas in the province of Punjab from 2003-2005, we found severe attack of a mealy bug species in an undisturbed area in Punjab University, Quaid-e-Azam Campus Lahore. The mealy bugs were found feeding on leaves, stems and flower heads of Parthenium. The infected plants first showed symptoms of dieback and ultimately dried to death. Five other weed species namely Boerhavia diffusa L., Achyranthes aspera L., Malvestrum tricuspidatum A. Gray, Sida spinosa L. and Xanthium strumarium L. were found to be attacked by the mealy bug. No field crop in Lahore was found to be attacked by the mealy bug.
