A survey of the spruce web-spinning sawflies of the genus Cephalcia Panzer in north-eastern China, with a guide to the identification of prepupae (Hym, Pamphiliidae)

The spruce web-spinning sawflies of the genus Cephalcia have been surveyed on two host plants (Picea Koraiensis and P. jezoensis) in both natural and artificial stands of north-eastern China. Ornamental trees were also included in the study. Five sites situated in the Provinces of Heilongjiang and Jilin and characterized by various elevations were considered in 1992-93. A total of nine species have been found, in the following decreasing order of abundance: C. abietis, C. arvensis (with two froms), C. fallenii, C. pallidula (new to China), C. alashanica, C. erythrogaster, C. fulva, C. klugii, and an unknown species. In most cases the adult specimens from China show a darker and more extended pigmentation with respect to the European ones. Some biological attributes (emergence period of adults, oviposition features, larval instars and feeding habits) are given for each species and compared with those known from European populations. A key for the practical identification of prepupae is presented. All information could be useful in monitoring, since these sawflies are considered among the main pests of various spruce species in this region.