关键词: 柳厚壁叶蜂, 垂柳, 虫瘿大小, 幼虫形态, 线性关系

Abstract: Pontania dolichura is a leaf-eating pest that harms and seriously affects the landscape greening effect of Salix babylonica. In order to study the correlation between the size of gall and the morphology of larva in different developmental stages, and to understand the occurrence and development law and the mechanism of gall formation, the gall length, gall width, gall thickness, gall wall thickness and larva body length, body width, head length and head width of P. dolichura of 55 groups in different investigation stages were systematically measured. Principal component analysis and detrended correspondence analysis (DCA) were carried out on the measured morphological characteristics data, and linear regression analysis was carried out among the morphological indexes of gall, larval morphological indexes and between gall and larval morphological indexes. The results showed that the larval development of P. dolichura showed obvious gradient changes, and there were significant linear relationships (P<0.000 1) between the morphological indexes of gall, as well as the morphological indexes of larva. However, the linear relationship between gall thickness and larval body length was a conditional function, that is, when the larval body length is less than or equal to 6.90 mm, there was a significant linear relationship, and the linear equation was y=1.771x + 0.653 (R2=0.920，P<0.000 1). Therefore, in practice, according to the linear relationship between the larval morphology and its gall, the growth and development status of the larva in the gall could be judged by easy-to-measure indexes such as the length, width, thickness and wall thickness of the gall, and the growth and development law of the larva could be determined, thus providing a scientific evaluation standard for the growth and development of the larva and a theoretical basis for its scientific control.

Key words: Pontania dolichura, Salix babylonica, gall size, larval morphological charactersitics, linear relationship