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马尾松毛虫幼虫的粪粒数量与大小,是随着世代的不同以及同一世代的不同龄期而有规律地变化。利用幼虫地面的落粪数量,来推算高大树上虫口密度,简便易行,准确可靠。
The mass and size of fecal pellets of the Dendrolimus punctatus larva vary regularly with age and with different ages of the same generation. The use of larvae on the ground to reduce the number of droppings, to estimate the population density of tall trees, simple, accurate and reliable.