一九七二年以来,菏泽地区暴发榆兰金花虫,连年造成严重危害,以第一、二代幼虫危害最重,每年两次将榆树叶大部份吃掉或全部吃光,使榆树基本停止了生长,甚至死亡。菏泽地区一九六六年约有榆树一亿株左右,自一九七二年以来,90％以上遭到榆兰金花虫的危害,严重影响了生长,据调查一般年平均材积生长量降低36％,其中约有60％左右的形成“老头榆”,失去了成材希望,造成了巨大的经济损失。 Since 1972, the Heze area outbreak of Ulmus gold pest insects, successive years of serious harm to the first and second generation of larvae hardest hit, twice a year most of the elm leaves eat or eat all, so that elm Basically stopped growing, or even died. About 19 million elm trees were found in the Heze area in 1966. Over 90% of the elm trees have been endangered by the genus Ulmus since 1997, seriously affecting the growth. According to the survey, the average annual volume growth decreased 36%, of which about 60% of the formation of “old elm”, lost hope for survival, resulting in huge economic losses.