Chlorophorus diadema Motsch. and Lyctus linearis Goeze are major borers which harm the wood of locust. Widely found in northern Jiangsu, they do serious damage to houses, furniture and other things made of locust wood. Observation of their lives has been made and descriptions concerned are given.1 . Chlorophorus diadema Motsch. : Seriously damages logs with diameters bet ween 5-10 cm. Adults prefer light. One generation in a year; egg period, 7-10 days; larval period, about 320 days; pupal period, 7-17 days; and adult period, 7-20 days.2 . Lyctus linearis Goeze: Seriously harms freshly-cut or freshly-processed wood of less than ten-years old trees. The damage is only done in the sap-wood, with powder falling off the holes. The adults have a preference for dark corners. One generation in a year, egg period, 6-15 days; larval period, about 302 days; pupal period, 16-22 days; and adult period, 14-26 days.3 . For prevention of the pests, use DDT, dipterex or ammonia water, or cut down trees in summer. For killing the pests, use DDT or DDVP.