Chinese hickory, Carya cathayensis Sargent (Juglandaceae), is a tree naturally occurring and industrially grown in China for the nuts that are valued for their taste and nutrient content. Larvae of a previously unknown species of gall midge were found feeding on male and female inflorescences of Carya cathayensis in Zhejiang and Anhui Provinces in eastern China, reducing pollination and fruit development, and causing substantial damage to the nut industry. The new species is named Contarinia caryafloralis Jiao, Bu Kolesik, its morphology is described, the basic biology is given, and the Cytochrome Oxidase subunit I (COI) mitochondrial gene segment is sequenced. Contarinia caryafloralis is the first gall midge known to feed on a Carya species native to Asia.
Keywords: Diptera, hickory blossom midge, gall midge pest, Chinese hickory, nut production.