明纹柏松毛虫各龄幼虫取食量和排粪量

The ingestion and defecation of the Dendrolimus suffuscus illustratus larvae

观察明纹柏松毛虫Dendrolimus suffuscus illustratus Lajonquiere各龄幼虫取食习性和排粪规律,测量各龄幼虫的取食量和排粪量。结果表明,1)明纹柏松毛虫幼虫多为8个龄期,幼虫全期取食,主要在夜间进食,取食量和排粪量随着幼虫龄期的增大而增加,其中第7龄和第8龄幼虫的平均取食量和排粪量最多;2)1～2龄幼虫取食量差异不明显(P>0.05),3龄后各龄期间差异明显(P<0.05);3)1～3龄间幼虫排粪重差异不明显(P>0.05),4龄后各龄期间差异明显(P<0.05);4)各龄幼虫粪长、粪宽、粪高间差异显著(P<0.05);5)粪长、粪宽、粪高、粪重与龄期之间呈显著正相关关系。

The feeding habits and defecation of Dendrolimus suffuscus illustratus Lajonquiere larvae were investigated.There are generally eight larval stages and larvae take food mainly at night.Food consumption and defecation increase with the growth of the larvae;both reaching a maximum in the 7th-8th ages.There was no significant difference in food consumption between the first and the second instars （P0.05） but there was a significant difference between the third and the 8th instars （P 0.05）.There was no significant difference in the amount of faeces produced by larvae of the first three instars （P0.05） but there was among the later five instars （P 0.05）.The length,width and height of faeces was notably different among the different instars （P 0.05） and there was a positive relationship between larval instar and faecal length,width,height and weight.