Abstract:

Objective: This study aims to describe a new species, Chinolyda cupressi Wei, sp. nov., that feeds on cypress, clarify its biological characteristics, and distinguish it from a similar species, Chinolyda flagellicornis Smith, 1860. Additionally, it seeks to resolve previous misidentifications and explore its differences in morphology and ecological adaptation from C. flagellicornis, as well as its speciation mechanisms. Method: A detailed morphological analysis was conducted on C. cupressi, focusing on its antennae, wings, and genitalia. Furthermore, genetic distance calculations, gene order analysis, and phylogenetic analysis of mitochondrial protein-coding genes were performed to evaluate the phylogenetic relationships and genetic differences between the two species. Result: This study found that C. cupressi exhibits distinct morphological traits, including antenna 33–34 segmented, flagellum of male antenna almost entirely black; inner margin of the large apical maculae in the fore wing just reaching vein 2r, cell 1M in male without black macula and only the outer third of the hind wing in male black; vein Sc1and Sc2 far away from the base of vein Rs+M, 1R1 much shorter than cell 1M, its length is about equal to its height; petiole of the anal cell in hind wing distinctly shorter than vein cu-a; sheath in lateral view long and narrow; apex of the subgenital plate in male obtusely rounded, penis valve with narrow and flat apical process; frontal basin in both sexes large and deep. Biological observations indicated that the host plant for this species is cypress (Cupressus funebris). C. cupressi sp. nov. exhibits aunivoltine life cycle in Chongqing and Hubei Provinces, with adult emergence peaking in early April and egg hatching occurring from late April to early May. Larvae are predominantly present from mid to late May. Assembling the mitochondrial genome revealed that the trnI(+)-trnQ(?)-trnM(+) cluster of C. cupressi and C. flagellicornis was rearranged to trnM(+)-trnI(+)-trnQ(?) cluster, and phylogenetic analysis showed that they form a monophyletic group with a close relationship. Genetic distance analysis indicated that the genetic differences between C. cupressi and C. flagellicornis were significantly greater than those within each species, with C. cupressi exhibiting a notably higher AT content than C. flagellicornis, supporting their classification as sister species. Conclusion: The new species reported, C. cupressi, shows morphological differences from its closely related species, C. flagellicornis. There are also significant differences in mitochondrial genomes between the two species. The specimen of this new species is preserved in the Asian Sawfly Museum, Nanchang, China (ASMN).

Key words: Pamphiliomorpha, Cephalciinae, Chinolyda cupressi, allopatric speciation, mitochondrial genome