Helionothrips pallidus, Xie & Li & Zhang, 2022

Xie, Yanlan, Li, Yajin & Zhang, Hongrui, 2022, The genus Helionothrips (Thysanoptera, Panchaetothripinae) in China, with two new species and an identification key, Zootaxa 5194 (3), pp. 392-402 : 398-399

Helionothrips pallidus sp.n.

( Figs 8 , 13 , 20 , 31–37 )

Female macroptera. Body color dark brown ( Fig. 31 ), head uniformly dark brown ( Fig. 35 ); fore legs yellow with a slight brown tint; mid and hind femora dark brown, tibiae dark brown with extreme base and apical third yellow; all tarsi yellow; antennal segments I–II and VI–VII brown, III–V yellow, VIII light brown ( Fig. 13 ); fore wing ( Fig. 8 ) dark brown at base, with a sub-basal white band and apical half pale, but brown at anterior and posterior margins of distal area, extreme apex brown; clavus dark brown.

Head about 1.4–1.5 times as wide as long, with many wrinkles in polygonal reticles ( Fig. 35 ); occipital collar arched medially, sculptured completely and posteromedian reticles with internal dots.Antennae 8-segmented, forked sense cones on segments III & IV long and curve, on III reaching to the midpoint of IV, on IV extending to the basal fourth of VI ( Fig. 13 ), simple dorsal sense cone on VI beyond apex of VIII, microtrichia present on segments IV–VI. Mouth cone rounded and moderately long, maxillary palps 2–segmented.

Pronotum entirely reticulate and with numerous internal wrinkles throughout ( Fig. 20 ); reticles of the anterior third, also posterolaterally, larger than those of the rest; discal setae long and slender. Mesoscutal median reticles and metascutal triangle reticles with weak internal wrinkles ( Fig. 33 ); metascutum median setae wide apart and far from anterior margin, campaniform sensilla (CPS) and median setae almost being in a transverse line; metascutellum entirely reticulate, about 2.3 times as wide as long. Fore wing with distinct veinal setae ( Fig. 8 ), first vein with 6–7 basal and 2 distal setae, second vein with 5–6 setae, posteromarginal cilia wavy; clavus with 4 veinal setae. Tarsi 1–segmented.

Abdominal tergites completely reticulate except for the posterior submedian smooth part, laterally reticles on tergites II–VII with distinct internal wrinkles; antecostal line of tergites III–VIII heavy and divided into a series of arches connected by a fine line; tergite VIII with posterior margin comb interrupted medially by lacking about 6 microtrichial teeth ( Fig. 37 ); tergite IX with 3 pairs of needle-like marginal setae, S1 and S2 subequal in length, slightly longer than S3 ( Fig. 37 ); tergite X with a complete dorsal longitudinal split. Sternites entirely sculptured with reticles longitudinally elongate posterior of antecostal line, three pairs of long and slender setae situated in front of posterior margin.

Measurements (holotype female in microns): Body length 1410. Head, length 103; width across genae 157. Eye, length 66; width 48. Pronotum, length 139; width 188. Fore wing length 940. Abdominal segments VIII–X median length 89, 103, 61. Antennal segments I–VIII length (width): 24(22), 34(29), 55(20), 45(22), 38(19), 26(18), 9(8), 35(4).

Male macroptera. Similar to female but smaller, abdomen more slender ( Fig. 32 ).Abdominal tergite IX with two pairs of thorn-like setae, the posterior pair slender and closer to each other than anterior pair ( Fig. 36 ); posteromedian of these setae with five wart-like tubercles; sternites VI–VIII each with a circular pore plate ( Fig. 34 ).

Measurements (paratype male, in microns). Body length 1395. Head, length 100; width across genae 143. Eye, length 63; width 42. Pronotum, length 136; width 178. Fore wing length 912. Antennal segments I–VIII length (width): 22(21), 33(28), 51(20), 43(21), 38(19), 25(18), 8(7), 32(4). Anterior pair of thorn-like setae on tergite IX length 33. Pore plate on sternites VI–VIII diameter 20, 21, 22.

Specimens studied. Holotype female, CHINA, Yunnan Province, Pingbian County, Dawei Mountain Nature Reserve, from leaves of ferns- Drynaria roosii , 4.v.2017 (Kong Bo), in collection of Yunnan Agricultural University , Kunming.

Paratypes: Yunnan Province, 6 females, 2 males taken from same locality and plant as holotype; Wuding County, Lion Mountain, 4 males from grass, 25.x.2016 (Li Yajin), 1 female and 1 male from Stellaria saxatilis , 8.xii.2017 (Li Yajin); Kunming City , 1 female from Stellaria saxatilis , 29.v.2017 (Li Yajin) . Guizhou Province, Hezhang County, Yelang National Forest Park, 6 females, 4 males from Oplismenus compositus , and 2 females, 1 male from ferns, 13.viii.2016 (Yan Xueqiang) .

Deposited in Australian National Insect Collection , Canberra : Wuding County, Lion Mountain , 1 female from grass, 25.x.2016 (Li Yajin); Kunming City , 1 female from Stellaria saxatilis , 29.v.2017 (Li Yajin); Yushe National Forest Park , 1 male from Cyclosorus parasiticus , 12.ix.2017 (Li Yajin) .

Etymology. Latin epithet “ pallidus ” meaning pale, refers to the fore wing colour.

Comments. Body sculpture of this new species resembles that of cephalicus and rugatus with the pronotum entirely covered with reticles having numerous wrinkles, also head, meso- and metascutum reticulate with internal wrinkles. However, it can be distinguished easily by the uniformly dark brown of antennal segment VI ( Fig. 13 ), versus the light brown and basal half yellow in cephalicus and rugatus ( Figs 12, 15 ); also, the length ratio of female abdominal segment IX and X is about 1.7 in pallidus sp. n., but 2.1–2.4 in cephalicus , and 2.5–2.8 in rugatus . Fore wing color pattern of this new species is similar to that of parvus and errans with the apical half almost pale (apex brown), but parvus and errans both are without internal wrinkles in head and thorax reticles. Moreover, males of pallidus sp. n. have a distinct pore plate present on abdominal sternites VI–VIII ( Fig. 34 ), but in parvus and errans , these are only on sternites VII–VIII.

Figures

FIGURES 1–9. Fore wing of Helionothrips species, female. (1) H. shennongjiaensis; (2) H. brunneipennis; (3) H. annosus; (4) H. aino; (5) H. phragmitesi sp. n.; (6) H. cephalicus; (7) H. rugatus; (8) H. pallidus sp. n.; (9) H. parvus.

FIGURES 10–19.Antennae of Helionothrips species, female. (10) H. phragmitesi sp. n.; (11) H. annosus; (12) H. rugatus; (13) H. pallidus sp. n.; (14) H. parvus; (15) H. cephalicus; (16) H. aino (segment IV sense cone extends only to the middle of VI); (17) H. aino (segment IV sense cone surpasses the apex of VII); (18) H. shennongjiaensis; (19) H. brunneipennis.

FIGURES 20–24. Pronotum of Helionothrips species, female. (20) H. pallidus sp. n.; (21) H. cephalicus; (22) H. phragmitesi sp. n.; (23) H. shennongjiaensis; (24) H. parvus.

FIGURES 31–42. Helionothrips species. H. pallidus sp. n. (31–37): (31) Female; (32) Male; (33) Meso- and metanotum, female; (34) Abdominal sternites V–VIII, male; (35) Head, female; (36) Abdominal tergites IX–X, male; (37) Abdominal tergites VIII–X, female. H. phragmitesi sp. n. (38–42): (38) Female; (39) Head, female; (40) Meso- and metanota, female; (41) Abdominal tergites I–III, female; (42) Abdominal tergites VIII–X, female.