BIOEFFICACY OF NEEM AND SYNTHETIC INSECTICIDES ON SERPENTINE LEAFMINER (LIRIOMYZA-TRIFOLII) (DIPTERA, AGROMYZIDAE) INFESTING PEA (PISUM-SATIVUM)

A field experiment was conducted during 1991-93 to test the efficacy of seed-kernel suspension of margosa or neem (Azadirachta indica A. Juss.) and some selected synthetic insecticides on the serpentine leafminer [Liriomyza trifolii (Burgess)] (Diptera: Agromyzidae) infesting pea (Pisum sativum L. sensu late). Cyfluthrin (Baythroid 50 wsc) 0.005%, dimethoate (Rogor 30 Ec) 0.03% and endosulfan (Endocel 35 Ec) 0.035% were effective in reducing the larval population (95.53%). Endosulfan 0.035% was found effective in increasing green-pod yield (96.28%). All the treatments were found effective and significantly superior to the control in reducing leaf damage (77.78-88.98%). However, endosulfan and dimethoate gave the best cost :benefit ratio (1 : 32.95 and 1 : 32.70).