Two new eriophyid mite species associated with Clematis terniflora var. mandshurica in China (Acari, Eriophyidae)

Abstract Two new eriophyid mite species associated with Clematis terniflora var. mandshurica, namely Aculops jilinensis sp. n. and Phyllocoptes terniflores sp. n., are described. Both species infest the tender leaves of host plants, inducing severe curling and blistering.

During field surveys in 2015, some leaves were found to be severely curled and blistered ( Figure 1). The curled and blistered leaves were checked with the aid of a microscope in the laboratory. Eriophyid mites were found and two new species were identified by the first and third authors.

Materials and methods
Sampling was made on the host plants in the field by the aid of a hand lens (30×), in Jilin Agricultural Science and Technology University, Jilin City, Jilin Province, China. The eriophyid mites gathered with host plant were placed in vials and stored in 75% ethanol, each vial was marked with the collection data. In the laboratory, the samples including mites were poured into a Petri dish and mite specimens were picked up using a fine pin and placed in Keifer's Booster to clear them. They were then slide-mounted with modified Berlese medium (Amrine and Manson 1996).
The morphological terminology used follows Lindquist (1996) and the generic classification is made according to Amrine et al. (2003). Specimens were measured following de Lillo et al. (2010). For each species, the holotype female measurement precedes the corresponding range for holotype and paratypes (given in parentheses). All measurements are in micrometres (µm) and represent lengths, when not otherwise specified. All type specimens are deposited as slide-mounted specimens in the Arthropod/Mite Collection of the Department of Entomology, Nanjing Agricultural University (NJAU), Jiangsu Province, China.
Relationship to host. Infesting the tender upper leaves; making leaves severely curled and blistered ( Figure 1A); hiding inside the curled surfaces ( Figure 1B).
Etymology. The specific designation jilinensis is derived from the name of location, Jilin City, where the new species was collected.
Remarks. Up to now, no eriophyoid mite species in the genus Aculops was reported from the host plant family Ranunculaceae. The new species is similar to the other species in the genus Aculops but can be easily distinguished by characters of specific prodorsal shield design. However, it is mostly similar to A. alachuae Keifer, 1966b, which also has dorsal annuli with rounded microtubercles, coxal plates with granules, female genital coverflap with longitudinal ridges and prodorsal shield with lined design and many granules. The new species can be separated from A. alachuae by its 7-rayed empodium (4-rayed in A. alachuae), median and admedian lines connected at the base by a pair of transverse lines forming an "arrow" (an "arrow" is present at the base of median line, but not connected with admedian lines in A. alachuae), submedian lines connected by diagonally reaching lines (submedian lines separated in A. alachuae), scapular seta sc short, 15 (14-20) (seta sc 27 in A. alachuae). Aculops alachuae was reported infesting Rhus copallinum L. var. leucantha (Jacq.) DC. (Anacardiaceae) from Florida, USA, galling host plant leaves (Keifer, 1966b). The new species is also similar to A. euphorbicolus (Keifer, 1964), which also have annuli with rounded microtubercles (53 dorsal annuli), coxal plates with granules, female genital coverflap with longitudinal ridges and prodorsal shield with lined design, 7-rayed empodium, but can be differentiated by prodorsal shield with many granules between lines (prodorsal shield without granules in A. euphorbicolus), median line complete (median line incomplete in A. euphorbicolus), opisthosoma with 72 (71-84) ventral annuli (opisthosoma with 60 ventral annuli in A. euphorbicolus), female genital coverflap with 13 (12-13) longitudinal ridges and two to three transverse lines at base (female genital coverflap with 8-10 ridges and two rows of granules in A. euphorbicolus). Aculops euphorbicolus was reported from Euphorbia corollata L. (Euphorbiaceae) from Virginia (USA), making deformed flower clusters or galls (Keifer, 1964). Some intraspecific differences in the design of the prodorsal shield were observed, especially between the median and admedian lines. The median line is complete in all specimens examined except the specimen illustrated in Figure 3C (median line interrupted at centre). Besides connected at base, median and admedian lines are always separated in specimens in Figures 3E and G. Median and admedian lines connected at base, basal 2/3 and 1/3 in Figures 3A, B, D, and F.
Relationship to host. Infesting the tender upper leaves and making leaves severely curled and blistered ( Figure 1A); hiding inside the curled surfaces ( Figure 1B).
Etymology. The specific designation terniflores is derived from the species name of the host plant, terniflora.
Remarks. The new species was compared with others in the genus Phyllocoptes infesting Clematis sp. This species is similar to P. atragenes [from C. alpina, infesting host plant as curled leaves], but can be differentiated from the latter by its shield pattern: the median and admedian lines are discontinuous (median and admedian lines continuous in P. atragenes), dorsal opisthosoma with 55 (55-60) annuli (dorsal opisthosoma with 48 annuli in P. atragenes) and dorsal annuli with rounded microtubercles (dorsal annuli smooth in P. atragenes). This species is also similar to P. heterogaster (Nalepa, 1891) [from C. recta, infesting host plant as abnormal hair], but can be differentiated from the latter by having its coxal plates with granules and short lines (coxal plates smooth in P. heterogaster), empodium 5-rayed (empodium 4-rayed in P. heterogaster), median line present on anterior of prodorsal shield (median line absent from anterior of prodorsal shield in P. heterogaster).