Essigella gagnonae, 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 : 104-107

Essigella gagnonae sp. n. Figs 1e, 3b

Holotype.

viviparous aptera, USA, Nevada, Douglas Co., 38.999°N 119.896°W, 10.vii.2013, on Pinus monticola , T. Théry & C. Favret leg. (USNM). Paratypes. 1 viviparous aptera, same data as holotype (QMOR); 12 viviparous apterae, California, El Dorado Co., 38.834°N 120.042°W, 09.vii.2013, on Pinus monticola , T. Théry & C. Favret leg., specimens on 10 slides (QMOR, CTT); 5 viviparous apterae, California, Lassen Co., HWY 89, 6 km N Jct HWY 36 & 89, 6600', S of Lassen Nat’l Park (77G20), 10.vii.1977, on Pinus monticola , J. T. Sorensen leg., specimens on 1 slide (EMEC); 5 viviparous apterae, Californica, Alpine Co., E side Ebbett’s Pass, HWY 4, 3 km E summit (77G41), 17.vii.1977, on Pinus monticola , J. T. Sorensen leg., speci mens on 1 slide (EMEC); 13 viviparous apterae, Washington, Kitsap Co., 8 km S Hood Canal Bridge, HWY 3 (78G49), 09.vii.1978, on Pinus monticola , J. T. Sorensen leg., specimens on 3 slides (4 + 4 + 5) (EMEC); 8 viviparous apterae, Washington, Grays Harbor Co., 16 km W Amanda Park, HWY 101 (78G54), 10.vii.1978, on Pinus monticola , J. T. Sorensen leg., specimens on 2 slides (4 + 4) (EMEC); 5 viviparous apterae, Nevada, Washoe Co., Mt Rose, Summit, Cmpgd, Toiyabe Nat’l Forest (78H9), 02.viii.1978, on Pinus monticola , J. T. Sorensen leg., specimens on 2 slides (2 + 3) (EMEC).

Diagnosis.

Like species of the E. californica complex and E. pini , E. gagnonae sp. n. has its 3rd and 4th abdominal dorsal terga usually bearing six setae. It can be distinguished from E. patchae by the presence 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. domenechi sp. n. and E. sorenseni sp. n. with the following characters: legs ranging from concolorous and slightly darker than body, to pro- and metatibiae slightly darkened with mesotibiae lighter and metafemora pale (tibiae concolorous in E. domenechi sp. n., pro- and metatibiae, and metafemora conspicuously darkened in E. sorenseni sp. n.); width of head between eyes = 289.0 ± 13.3 (300.7 ± 14.2 for E. domenechi sp. n., and 353.6 ± 15.3 for E. sorenseni sp. n.); ratio of 3rd / 5th antennal segments <1.6 (<1.6 for E. domenechi sp. n. but> 1.6 in E. sorenseni sp. n.); overall pubescence medium-sized to long with average length of the longest dorsal setae of metafemora = 59.8 ± 9.8 (29.7 ± 4.2 for E. domenechi sp. n., and 51.2 ± 10.7 for E. sorenseni sp. n.); average length of the longest ventral seta of metafemora = 43.1 ± 5.4 (32.6 ± 4.5 for E. domenechi sp. n., and 54.4 ± 5.6 for E. sorenseni sp. n.); average length of the longest dorsal seta of metatibiae = 85.7 ± 10.8 (44.0 ± 8.1 for E. domenechi sp. n., and 76.4 ± 15.8 for E. sorenseni sp. n.); average length of the longest ventral seta of metatibiae = 49.4 ± 9.5 (37.5 ± 7.0 for E. domenechi sp. n., and 67.7 ± 12.0 for E. sorenseni sp. n.); average length of the longest frontal seta = 58.7 ± 8.3 (32.6 ± 7.5 for E. domenechi sp. n., and 53.4 ± 11.9 for E. sorenseni sp. n.); average number of setae of the genital plate = 23.6 ± 2.1 (22.0 ± 2.1 for E. domenechi sp. n., and 31.6 ± 1.7 for E. sorenseni sp. n.). Essigella gagnonae sp. n. is for now morphologically not distinguishable from E. californica , the latter being highly variable, nor from E. hoerneri . Essigella gagnonae sp. n. can be separated from E. californica , E. domenechi sp. n., E. hoerneri , and E. sorenseni sp. n. with the DNA characters shown in Table 2.

Description.

Viviparous apterae (prepared specimens): body with pale tegument sometimes slightly yellowish, with visible pigmented scleroites. Legs ranging from concolorous, slightly darker than body, to pro- and metatibiae slightly darkened, darker than body and mesotibiae. Antennae pale, the 5th, the 4th and the apical third part of the 3rd segment darkened. URS elongated, with lateral margins subparallel, bearing rows of spinules. Overall pubescence medium-sized to long, dorsal setae of appendages incrassate, ventral ones acute, in specimens with very long dorsal setae in metafemora and metatibiae (> 100 µm), these setae almost acute to acute (Fig. 3b), straight to sinuated. Terga of abdominal segments 3 and 4 with six dorsal setae. Genital plate with 21-26 setae (23.6 ± 2.1) (n = 9). Cauda obvious but not too protruding, apically rounded, slightly turned upward. BL: 1600-2000 (1800 ± 130) (n = 19). HWE: 271.0-311.9 (289.0 ± 13.3) (n = 13), LAIII: 157.6-197.4 (178.1 ± 11.1) (n = 29), LAIV: 90.2-111.6 (99.7 ± 6.3) (n = 33), LAV: 116.0-141.6 (125.4 ± 5.8) (n = 20), LPRIV: 21.5-29.1 (24.3 ± 1.8) (n = 21), LPRV: 18.5-22.6 (20.6 ± 1.2) (n = 18), LPT: 7.6-16.8 (12.1 ± 2.5) (n = 23), LURS: 64.5-79.8 (72.0 ± 3.8) (n = 18), LMF: 650.3-798.5 (707.3 ± 38.6) (n = 22), WMF: 69.5-104.6 (87.0 ± 10.8) (n = 29), LMT: 876.1-1104.2 (999,9 ± 67.4) (n = 25), WMT: 33.8-52.5 (42.3 ± 4.1) (n = 40), WS: 34.4-42.6 (38,9 ± 2.5) (n = 18), LMB: 101.8-131.0 (116.1 ± 8.0) (n = 36), LMD: 180.3-209.9 (195.0 ± 8.6) (n = 34), LFS: 44.4-80.2 (58.7 ± 8.3) (n = 26), LDMFS: 42.0-82.9 (59.8 ± 9.8) (n = 43), LVMFS: 31.5-52.6 (43.1 ± 5.4) (n = 42), LDMTS: 60.9- 107.7 (85.7 ± 10.8) (n = 46), LVMTS: 30.5-74.5 (49.4 ± 9.5) (n = 46).

Comments.

USA, California, Nevada, and Washington, on Pinus monticola Douglas ex D. Don. The species occurs in elevated places where P. monticola is present. This species corresponds to the E. californica population living on P. monticola (cluster H2) shown in Théry et al. (in press).

Etymology.

This species is dedicated to Édeline Gagnon, PhD student at the University of Montreal (QC, Canada) for her help in genetic analyses with which the species was discovered.