The gall of A. lutea is a simple but abrupt swelling on a stem (Fig. 2). It may occur on older stems as well as the current year's growth, but it is always woody with thickened walls. Among 3 galls dissected, 2 were monothalamous and measured 9.5-14.5 mm in length, 4.5-5.5 mm in width, and 5.0-8.0 mm in depth. The polythalamous gall contained 2 larvae and measured 14.0 x 5.0 x 8.0 mm. The cavity size for each was 5.0 x 2.0 mm. The only noticeable effect A. lutea galls had on the host plant was the stunting or prevention of stem growth from axillary buds on the swelled portions of stems.