DNA barcoding reveals the protogyne and deutogyne of Tegolophus celtis sp. nov. (Acari: Eriophyidae)

A few eriophyoid mites have two forms of adult female, called protogyne and deutogyne. The latter form is thought to increase survival under unfavorable conditions. The two forms have distinct morphological characters, which often cause them to be recognized as different species. Molecular species delimitation provides a useful tool to solve these misunderstandings. Here we describe a new species of eriophyoid mite, Tegolophus celtis sp. nov., that has protogyne and deutogyne forms infesting Chinese hackberry, Celtis sinensis Pers. (Cannabaceae), an ornamental tree in China. The two forms can be easily differentiated by body shape (fusiform and triangular, respectively) and body color (light yellow and red, respectively). The putative protogyne and deutogyne forms of T. celtis were identified by using fragments of three genes, a mitochondrial gene (COI) and two nuclear genes (18S rRNA and 28S rRNA). Kimura-2-parameter distances of these three fragmental sequences were between 0.0% and 0.9%. Phylogenetic topologies strongly support the occurrence of the protogyne and deutogyne forms with high bootstrap and Bayesian values. The population structure of T. celtis changed with the seasons, with deutogynes being most abundant in summer and protogynes being most abundant in spring. The new species described herein are vagrants on their host plants.