AbstractLarvae of the Manchurian catalpa shoot borer Sinomphisa plagialis (Wileman) mainly damaged young shoots of Manchurian catalpa (Catalpa bungei) and ovate catalpa (Catalpa ovata). The typical symptom was production of spindle galls on damaged parts of shoots or branches, usually confined to seedlings, vigorously growing shoots, twigs and branches, as well as young trees below 3 m in height. Feeding occurred from early April to late October. In the Jiaodong peninsula, where there were one to two generations in a year, whereas in the mountainous area of central and southern Shandong, there were always two generations. Larvae had five instars. The longevity of adults was 3–11 days; eggs of the summer generation 7–9 days, overwintering generation 4–6 days; larvae of the summer generation 42–48 days; pupae of the summer generation 13–16 days, of the overwintering generation 22–26 days. Most overwintered in the pith as fifth instar larvae.