Abstract: Agenocimbex ulmusvora Yang is a newly discovered insect pest that causes severe damage to leaves of Chinese elm and White elm.The sawfly completes its life cycle in a year.The larvae enter the root regions of bushes and weeds,or the upper soil layer,then make cocoons.They oversummer and overwinter as prepupa.The prepupa occurs in the last ten days of March and the eclosion,copulation and oviposition happen in the first ten days of April.The larval stage lasts 32.28±2.27 d.The average feed intake for one larva is 25903.83± 6778.55 mm2.As the larvae mature in the last ten days of May,they crawl down from tree to make cocoons,oversummer and overwinter.The female lays its eggs mainly on leaves of small bushes or lower branches of the trees.The surface of the larvae is smooth and bare,so it is sensitive to chemicals.Good results can be achieved by control in a proper time.5% cypemethrin,2.5% deltamethrin (1;3000),80% dichlorvos or 90% crystal trichlorfon (1;800) can be used for effective control.