Uttar Pradesh Council of Agricultural Research, A-11, Nirala Nagar, Lucknow, U.P.
Trials conducted on the efficacy of Neochetina spp. against water hyacinth in different ponds of eastern and central Uttar Pradesh during 1991–1993 revealed that the insects usually established within two months of release. Ponds having satisfactory buildup of insects showed large scale petiole damage resulting in yellowing, withering and ultimately decay of plants within a period of 2 to 2.5 years. The infested plants also showed reduced flowering in comparison to the normal ones. In 14 ponds, where establishment of insects and damage caused by them was satisfactory, the suppression of weed was observed up to desired level. It was further observed that population buildup of weevils and extent of damage to water hyacinth plants increased gradually.
