Feeding Behavior of the Cabbage Bug, Eurydema rugosa MOTSCHULSKY (Hemiptera : Pentatomidae) on the Cruciferous Plants)

抄録

While the adult of the cabbage bug, Eurydema rugosa MOTSCHULSKY, feeds mainly on mesophyll and parenchymatous cells of the stem and on the pod and flower bud of the host plant, the nymph feeds not only on mesophyll but also on vascular element; the younger it is, the more it feeds on the latter.Immediately after feeding, an irregularly round, whitish spot is manifesting itself around the point where the stylets were thrust. Among the spots inflicted by the bug of various stages, no difference could be seen in external appearance except in size. The maximum radius of the feeding spot was the same as the total length of the first and second segments of the proboscis of the bug, and the size of the spot never grew larger but remained the original size also with the lapse of time. It is suggested that the injury caused by the bug is primarily due to the mechanical destruction of cells in the tissue attacked by its stylets.The mechanisms of injury caused by the bug did not change with the progress of stage.The bug always left many granular substances at the end of and along the feeding puncture within the attacked tissue. The tube-like salivary sheath lining the feeding puncture was not always formed, for its constructioin was dependent on the feeding site and the stage of the bug.