Essigella domenechi, Thery, Thomas, Kanturski, Mariusz & Favret, Colin, 2018

Thery, Thomas, Kanturski, Mariusz & Favret, Colin, 2018, Molecular data and species diagnosis in Essigella Del Guercio, 1909 (Sternorrhyncha, Aphididae, Lachninae), ZooKeys 765, pp. 103-122 : 104

Essigella domenechi sp. n. Figure 1d

Holotype.

viviparous aptera, USA, California, Alpine Co., 38.328°N 119.637°W, 10.vii.2013, on Pinus albicaulis , T. Théry & C. Favret leg. (USNM). Paratypes. 8 viviparous apterae, same data as holotype (QMOR, CTT).

Diagnosis.

Like species of the E. californica complex and E. pini , E. domenechi sp. n. has its 3rd and 4th abdominal dorsal terga usually bearing six setae. The species can be distinguished from E. patchae by the presence of rows of spinules on the URS (absent or faint in E. patchae ; Fig. 2b, d); from E. pini by a relatively elongate URS with subparallel lateral margins (URS with margins rounded and convergent at base in E. pini ; Fig. 2a, c); from E. gagnonae sp. n. and E. sorenseni sp. n. with the following characters: tibiae and femora more or less concolorous showing almost or same color as that of body (pro- and metatibiae and metafemora conspicuously darkened in E. sorenseni sp. n., pro- and metatibiae sometimes slightly darkened in E. gagnonae sp. n.), dorsal tegument thick; width of head between eyes = 300.7 ± 14.2 (289.0 ± 13.3 for E. gagnonae sp. n., and 353.6 ± 15.3 for E. sorenseni sp. n.); ratio of 3rd / 5th antennal segments <1.6 (<1.6 for E. gagnonae sp. n. but> 1.6 in E. sorenseni sp. n.); overall pubescence short or medium-sized with average length of the longest dorsal seta of metafemora = 29.7 ± 4.2 (59.8 ± 9.8 for E. gagnonae sp. n., and 51.2 ± 10.7 for E. sorenseni sp. n.; average length of the longest ventral seta of metafemora = 32.6 ± 4.5 (43.1 ± 5.4 for E. gagnonae sp. n., and 54.4 ± 5.6 for E. sorenseni sp. n.); average length of the longest dorsal seta of metatibiae = 44.0 ± 8.1 (85.7 ± 10.8 for E. gagnonae sp. n., and 76.4 ± 15.8 for E. sorenseni sp. n.); average length of the longest ventral seta of metatibiae = 37.5 ± 7.0 (49.4 ± 9.5 for E. gagnonae sp. n., and 67.7 ± 12.0 for E. sorenseni sp. n.); average length of the longest frontal seta = 32.6 ± 7.5 (58.7 ± 8.3 for E. gagnonae sp. n., and 53.4 ± 11.9 for E. sorenseni sp. n.); average number of setae of the genital plate = 22.0 ± 2.1 (23.6 ± 2.1 for E. gagnonae sp. n., and 31.6 ± 1.7 for E. sorenseni sp. n.). Essigella domenechi sp. n. is morphologically not distinguishable from E. californica , the latter being highly variable, nor from E. hoerneri . Essigella domenechi sp. n. can be separated from E. californica , E. gagnonae sp. n., E. hoerneri and E. sorenseni sp. n. with the DNA characters shown in Table 1.

Description.

Viviparous apterae (prepared specimens): body with pale tegument, with visible pigmented scleroites; dorsal tegument visibly thicker, sclerotized. Legs quite pale, concolorous, more or less the same color than that of body. Antennae pale, the 5th, the 4th and the apical third part of the 3rd segment of antennae darkened. URS elongated, with lateral margins subparallel, bearing rows of spinules. Overall pubescence short to medium-sized, dorsal setae of appendages incrassate, ventral ones acute. Terga of abdominal segments 3 and 4 with six dorsal setae. Genital plate with 19-25 setae (22.0 ± 2.1) (n = 6). Cauda obvious but not too protruding, apically rounded, slightly turned upward. BL: 1600-2100 (1800 ± 170) (n = 7). HWE: 283.2-326.0 (300.7 ± 14.2) (n = 7), LAIII: 162.2-184.6 (171.8 ± 6.5) (n = 13), LAIV: 96.4-106.7 (101.0 ± 4.1) (n = 9), LAV: 113.7-124.4 (120.2 ± 4.1) (n = 5), LPRIV: 20.8-25.8 (23.0 ± 1.6) (n = 9), LPRV: 17.6-21.9 (19.6 ± 1.4) (n = 9), LPT: 8.5-14.5 (11.9 ± 1.9) (n = 9), LURS: 71.4-79.2 (75.2 ± 2.8) (n = 6), LMF: 675.7-728.8 (708.3 ± 24.2) (n = 6), WMF: 68.2-77.3 (74.9 ± 2.9) (n = 11), LMT: 975.1-1074.4 (1027.8 ± 38.2) (n = 9), WMT: 36.8-43.9 (41.4 ± 2.2) (n = 12), WS: 36.7-43.5 (40.4 ± 2.2) (n = 9), LMB: 107.2-114.4 (110.9 ± 2.3) (n = 11), LMD: 189.4-206.4 (194.9 ± 6.9) (n = 11), LFS: 18.7-39.5 (32.6 ± 7.5) (n = 7), LDMFS: 25.2-36.8 (29.7 ± 4.2) (n = 12), LVMFS: 26.1-44.0 (32.6 ± 4.5) (n = 12), LDMTS: 33.7-61.8 (44.0 ± 8.1) (n = 12), LVMTS: 24.7-48.1 (37.5 ± 7.0) (n = 12).

Comments.

USA, California, on Pinus albicaulis Engelmann, known from Stanislaus National Forest at high elevation (type series). The species probably occurs in other high mountains where P. albicaulis is present. This species corresponds to the E. californica population living on P. albicaulis (cluster H3) shown in Théry et al. (in press).

Etymology.

This species is dedicated to Boris Domenech, PhD student at the University of Montreal (QC, Canada) for his comments in genetic analyses with which the species was discovered.