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 surv eyed on two host plants (Picea Koraiensis and P. jezoensis) in both na tural and artificial stands of north-eastern China. Ornamental trees w ere also included in the study. Five sites situated in the Provinces o f 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 (wit h two froms), C. fallenii, C. pallidula (new to China), C. alashanica, C. erythrogaster, C. fulva, C. klugii, and an unknown species. In mos t cases the adult specimens from China show a darker and more extended pigmentation with respect to the European ones. Some biological attri butes (emergence period of adults, oviposition features, larval instar s and feeding habits) are given for each species and compared with tho se known from European populations. A key for the practical identifica tion of prepupae is presented. All information could be useful in moni toring, since these sawflies are considered among the main pests of va rious spruce species in this region.