Mesocallis (Paratinocallis) occulta Lee Y., 2018

Lee, Yerim, Kanturski, Mariusz & Lee, Seunghwan, 2018, Psammoecus simonis Grouvelle 1892, Zoological Studies 57 (17), pp. 1-20 : 12-16

Mesocallis (Paratinocallis) occulta Lee Y. sp. nov.

( Figs. 1 , 2 , 4 c-d, 9, 11; Table 1)

urn:lsid:zoobank.org:act:21873460-79B3-4ECE-BD7B-BD9100F727A6

Material examined: Holotype: 1 alate viviparous female, Sinwon-ri , Yongin-si, GG, South Korea, 37°18'56"N, 127°12'56"E, on Corylus sp. , Yerim Lee and Hyoseok Lee leg., 16.v.2014, no. 140516YR-12.

Paratypes: 9 alate viviparous females, same data as holotype, including DNA voucher no. Co12; 1 alate viviparous female, Silnae-pass, Hwacheon-gun, GW, 38°09'05"N, 127°31'02"E, on Corylus sieboldiana, Yerim Lee leg., 1.v.2014, no. 140501YR-15, DNA voucher no. Co9; 1 alate viviparous female, Mt. Jugeumsan, Gapyeonggun, GG, South Korea, 38°08'38"N 126°54'17"E, on Corylus heterophylla, Yerim Lee leg., 9.v.2014, no. 140509YR10, DNA voucher no. Co11; 30 alate viviparous females, Mt. Hwayasan, Gapyeonggun, GG, South Korea, 37°40'17"N 127°25'40"E, on Corylus heterophylla, Yerim Lee leg., 26.v.2014, no. 140526YR-1, including DNA voucher no. Co16- 1; 2 alate viviparous females, Mt. Gyeryongsan, Gongju-si,, CN, South Korea, 36°20'33"N, 127°12'21"E, on Corylus heterophylla, Yerim Lee and Hyoseok Lee leg., 24.iv.2015, no. 150424YR- 3, DNA voucher no. Mes3-1, Mes3-2; 1 alate viviparous females, Mt. Gwanggyosan, Suwonsi, GG, South Korea, 37°19'40"N, 127°00'54"E, on Corylus heterophylla, Yerim Lee and Hyoseok Lee leg., 10.v.2015, no. 150510YR-5, DNA voucher no. Mes5-1.

Etymology: The species name, occulta is derived from Latin adjective, ‘occulta’ (hidden).

Diagnosis: This species is morphologically very similar to M. (P.) corylicola Higuchi in that it has a pale body and URS that is 0.07-0.09 mm in length. However, it can be distinguished by its shorter ANT IV length, 0.12-0.22 mm (0.23-0.32, in M. corylicola ), shorter ANT V length, 0.13-0.18 mm (0.12-0.22, in M. corylicola ), ANT 0.60-0.77 × BL (0.75-0.92, in M. corylicola ) and URS 1.00-1.14 × HT II (0.80-1.00 in M. corylicola ).

Description (Alate viviparous female): Color in life: Head pale yellow, ANT pale with slight dark margin of ANT III and BASE. Thorax and abdomen pale yellow. Legs pale with 1/9 of fore tibiae and tarsi fuscous. Wing vein Cu1b of forewing bordered with brown pigment. SIPH pale. Cauda and anal plate pale.

Morphology: Body oval, BL 0.95-1.44 mm. Head smooth with a flat median protrusion on frons, epicranial suture weakly developed, head dorsum without tubercles with 8 acuminate setae shorter than 0.01 mm long. ANT 6-segmented, 0.73-1.07 mm long, ANT 0.60-0.77 × BL, ANT III longest with 5-9 narrow elliptical secondary rhinaria in a row on the whole segment, bearing 3-4 short pointed setae, ANT III-VI imbricated with inconspicuous pointed setae, Ls ANT III × 0.50- 1.00 BD III, ANT IV without secondary rhinaria, ANT V shorter than ANT IV, BASE with a single inconspicuous seta, PT 0.83-1.10 × BASE. Rostrum not reaching to middle coxae, URS 0.07- 0.09 mm long with 4-6 accessory setae, URS 0.75-1.00 × BASE, 1.00-1.14 × HT II. Thorax smooth without tubercles. Fore coxae slightly enlarged, longest setae on TIBIAE III 1.50 × middle width of TIBIAE III, HT I with 8 chaetotaxy, HT II 0.07-0.09 mm long. Wing vein Rs weakly developed. Dorsal spinal setae sometimes on small elevations, conspicuous tubercles not developed, ABD VIII bearing a pair of short setae, ABD margin I-IV with 0.01-0.02 mm long of 2 setae on short cone-shaped tubercle, 4th marginal tubercle 0.01-0.02 mm. SIPH cylindrical, truncated, 0.04-0.06mm long. Cauda knobbed, 0.07-0.09 mm with 9-13 setae. Anal plate bilobed, each lobe with 7-10 setae.

(a) (b) (c) (e) (d) (f) (g)

Distribution: So far, the new species is known from Gangwon-do, Gyeongsangnam-do, and Jeollanam-do in South Korea.

Host plant: Representatives of the new species feed on the underside of leaves of Corylus sp. ( Betulaceae ).

Remarks: This species was first recognized as a cryptic species of M. (P.) corylicola in the previous DNA barcoding study ( Lee et al. 2017).

Molecular identification

The overall mean genetic distance was 7.33% for the 45 partial COI sequences of the 5 Mesocallis species. All species showed very low intraspecific distance level, ranging from 0% to 1.07% ( Table 2). Among the five species, intraspecific distance was most varied in M. corylicola , with ranges of up to 1.07%; in contrast, 0% of intraspecific distance was observed among M. carpinicola sp. nov. In the remaining species, intraspecific distances were below 0.61%. Interspecific distance ranged from 6.21% to 12.72%. 11.81% to 12.72% of highest interspecific distances were observed between M. pteleae and M. corylicola ( Table 2). M. corylicola and M. occulta sp. nov. showed 6.21% to 7.40% of lowest interspecific distances.

The COI sequence NJ tree showed that the 45 sequences are clearly divided into five specific groups ( Fig. 12 ). This result indicates that molecular identification based on COI barcoding region is effective for Mesocallis .

Haplotype analysis results found 128 variable positions in the 658bp COI region. Overall, 19 different haplotypes were observed, consisting of 1 haplotype for M. carpinicola sp. nov., 3 for M. pteleae , 4 for M. sawashibae , 9 for M. corylicola and 2 for M. occulta sp. nov. ( Fig. 13 ).

Figures

Fig. 1. Collection sites of Mesocallis spp. specimens collected in this study (●) and museum specimens (♦).

Fig. 2. A pictorial key to the species of Mesocallis in the Korean peninsula. © 2018 Academia Sinica, Taiwan

Fig. 4. Representatives of Mesocallis (Paratinocallis) of in life: (a) alate viviparous female of M. (P.) corylicola; (b) alatoid nymph of M. (P.) corylicola; (c) alate viviparous female of M. (P.) occulta sp. nov.; (d) alatoid nymph of M. (P.) occulta sp. nov. © 2018 Academia Sinica, Taiwan

Fig. 12. Neighbor-joining tree of COI partial gene sequences of Mesocallis spp. (45 sequences of 5 species)

Fig. 13. Median-joining network for COI partial gene sequences of Mesocallis spp. (45 sequences of 5 species). © 2018 Academia Sinica, Taiwan