http://www.eje.cz Kang, 2002). Cold hardiness essentially refers to the ability of insects to survive long-or short-term exposure to low temperatures (Lee, 1989). Therefore, survival at low temperatures is a good indicator of cold hardiness, which is thought to be closely related to the supercooling point (SCP) of a species, which is the lower temperature at which it dies (Lee & Denlinger, 1985; Hao & Kang, 2004; Jing & Kang, 2004). The supercooling point is an important indicator of the cold hardiness and overwintering strategy of an insect (Bale, 1996; Jing & Kang, 2002; Feng et al., 2016). I n addition, previous research indicates that insect cold hardiness is closely connected with changes in many parameters such as water, lipid and glycogen content (Bale, 2002; Wang et al., 2011; Feng et al., 2015). Many cold-hardy insects produce and accumulate low molecular weight metabolites to increase their supercooling capac

Streltzoviella insularis (Staudinger) is an important tree‐boring pest, that primarily damages Sophora japonica (Linnaeus) and Ginkgo biloba (Linnaeus), as well as other common species, at great economic cost to the urban landscape construction industry in China. In the present study, the alimentary canal morphology of S. insularis was observed using light microscopy, and its ultrastructure was investigated by scanning and transmission electron microscopy. The foregut of S. insularis can be divided into the pharynx, esophagus, crop, proventriculus, and cardiac valve. The well‐developed crop forms the longest section of the foregut. It is able to store large amounts of food and is lined with a monolayer of epithelial cells. Many sclerotized microspines occur on the surface of the anterior intima and there are dense spines on the posterior intima of the proventriculus. Epithelial cells of the midgut include columnar cells, goblet cells, and regenerative cells, but endocrine cells are absent. The hindgut consists of the pyloric valve, ileum, and rectum. There is no clear distinction between the ileum and colon. The intima surface of the pyloric valve carries many microspines, whereas the intestinal wall of the rectum is thin with well‐developed rectal pads. The rectal epithelial cells form a squamous monolayer. A cryptonephric excretory system is located in the hindgut. There are six spiral Malpighian tubules, in which a cellular layer on a basement membrane encloses a lumen. These results will provide the basis for further studies of the structure and function in S. insularis larvae.