Poljanka curticapillata Lü, Luo & Yao, 2023

Lü, Ting, Du, Si-Le, Luo, Xin-Yu, Ren, Dong & Yao, Yun-Zhi, 2023, A new species of Protopsyllidiidae (Hemiptera, Sternorrhyncha) from the Middle Jurassic of northeastern China, Zootaxa 5396 (1), pp. 41-49 : 44-47

Poljanka curticapillata Lü, Luo & Yao , sp. nov.

( Figs 2 , 3 )

Material. Holotype, CNU-PSY-NN2023002PC (part and counterpart), a well-preserved specimen, with body mainly preserved and a rather clear forewing (male); paratype, CNU-PSY-NN2023003PC (male).

Etymology. Species name is derived from the Latin word ‘ curt- ’ (short) and ‘ capillata ’ (setae), referring to the short setae on the antennae, legs, thorax and wings. The gender is feminine.

Locality and horizon. Daohugou Village, Ningcheng County, Inner Mongolia, China; Middle Jurassic, Jiulongshan Formation.

Diagnosis. Scapus 1.33–1.4 times thicker than pedicelli, pedicelli about three times as thick as flagellomeres, flagellomeres with 6 slender segments and one swollen section at apex, apical section divided into 6 subsections; gena conical, with setae; all tibiae with visibly 4 metatibial apical spurs at distal apex; basal tarsomeres of hind tarsi about twice longer than apical tarsomeres; forewing with R long, about 1.68 times the length of M + Cu 1; M 3+4 weakly sinusoidal; Cu 1a about 3.63 times the length of the curved Cu 1b.

Description. Body relatively small, approximately twice as long as wide.

Head length about 0.5 mm; plane of head nearly vertical; vertex with several setae; gena conical, and with setae; eyes subround; antennae rather long, about 4.74 times the length of the head; antenna filiform, with setae, divided into scapus, pedicelli and flagellomeres; scapus globular, 1.33 times as thick as pedicelli; pedicelli cylindrical, three times as thick as flagellomeres; flagellomeres 1 to 6 slender and apical flagellum slightly swollen, all flagellomeres with long setae on both sides; scapus equal to pedicelli in length; flagellomere segment Ⅰ the longest, about 1.69 times the length of scapus and pedicelli combined, 1.3 times the length of segment II; segments Ⅰ–VI slightly swollen at apex; apical flagellum divided into 6 subsections.

Pronotum well-developed; mesopraescutum, mesoscutum and mesoscutellum visible; junctions between pronotum and mesopraescutum, and between mesopraescutum and mesoscutum with dense setae, mesoscutum with dense setae; propleuron long and cylindrical, with numerous short stiff setae.

Trochanter approximately cylindrical. Femora stout, both sides swollen slightly, middle area the thickest, surface with dense setae; fore femora 2.57 times as thick as corresponding tibiae; middle femora 2.28 times as thick as corresponding tibiae; hind femora 3.14 times as thick as corresponding tibiae. Tibiae slender, all tibiae slightly swollen at apex, with 4 visible apical spurs; all tibiae neatly covered with setae, hind tibiae setae longer and thicker than fore tibiae and middle tibiae; hind tibiae the longest, about 1.41 times the length of fore and middle tibiae. Tarsi two-segmented, basal tarsomere of fore and middle legs a little longer than corresponding apical tarsomere, and basal tarsomere of hind leg about 2.11 times as long as apical tarsomere; hind tarsi the longest, significantly longer than fore and middle tarsi; two claws at apex of tarsi.

Forewing length about 3.82–4.25, narrow basally, rounded apically, with short, fine, dense setae on margin; short setae on vein, long and stiff setae on A 1; small evident ring around each setal base on vein, the distance between near small rings equal to the length of the setae on all veins excluding A 1. R slightly longer than M + Cu 1, about 1.68 times as long as M + Cu 1. R forked, R 1 and Rs separated at 0.77 mm from wing base, R 1 not forked; Rs long, clearly longer than R 1; R 1 and Rs parallel from base, subsequently reaching to costal margin. M short and straight, forked into M 1+2 and M 3+4, distally than R forked and more basally than Cu 1 forked; M 1+2 long and straight, about 2.6 times the length of M; M 3+4 bending towards posterior margin and slightly sinusoidal, about 2.38 times as long as M. Cu 1 forked into Cu 1a and Cu 1b; Cu 1a long and curved, Cu 1b short and curved, Cu 1a 3.63 times as long as Cu 1b. Cu 2 nearly parallel to Cu 1. Cell m 1 elongated, significantly longer than cell cu 1. Hindwing smaller than forewing, marginal fringe with short, soft, dense setae.

Abdomen roughly oval, the preservation of apical abdomen poor. Tergites III–VII well-developed; apical anal tube neatly covered with a row of setae, setae base with small ring. Sternites III–VII well-developed, segment VII apex possible with part of sperm pump.

Measurements (in mm). Holotype, CNU-PSY-NN2023002PC: Body length 3.84, maximal width 1.90; head length 0.50; antennal segments length Ⅰ–VIII: 0.13, 0.13, 0.44, 0.38, 0.34, 0.29, 0.20, 0.17, apical flagellum length 0.29; pronotum length 0.36; mesopraescutum length 0.33; mesoscutum length 0.64; mesoscutellum length 0.34; length of fore leg: femur 0.83, tibia 1.25, tarsomeres Ⅰ–II: 0.29, 0.28; length of middle leg: femur 0.85, tibia 1.25, tarsomeres Ⅰ–II: 0.25, 0.23; length of hind leg: femur?, tibia 1.71, tarsomeres Ⅰ–II: 0.59, 0.28; forewing length 3.82, width 2.06; vein lengths: R 0.74, R 1 2.45, Rs 2.90, M + Cu 1 0.44, M 0.96, M 1+2 2.54, M 3+4 2.28, Cu 1 1.89, Cu 1a 0.98, Cu 1b 0.27. Paratype, CNU-PSY-NN2023003PC: Body length 4.11, maximal width 1.90; head length 0.65; antennal segments length Ⅰ–VIII: 0.14, 0.14, 0.47, 0.45, 0.39, 0.32, 0.25, 0.19, apical flagellum length 0.30; pronotum length 0.41; mesopraescutum length 0.33; mesoscutum length 0.70; mesoscutellum length?; length of fore leg: femur 0.80, tibia 1.11, tarsomeres Ⅰ–II: 0.22, 0.22; length of middle leg:?; length of hind leg: femur?, tibia?, tarsomeres Ⅰ–II: 0.52, 0.32; forewing length 4.25, width 2.35; vein lengths: R 0.66, R 1 3.50, Rs 3.44, M + Cu 1 0.50, M 0.90, M 1+2 2.63, M 3+4 2.38, Cu 1 1.90, Cu 1a 0.90, Cu 1b 0.26.

Remarks. The new species is assigned to Poljanka due to the following features: scapus thickest, apical flagellum swollen; rostrum straight, long; femora thicker and shorter than the tibiae, apical tibiae swollen, with visible metatibial apical spurs ( Yang et al. 2013); forewing narrow at base, rounded at apex; vein R 1 not forked ( Klimaszewski 1995); branches of M longer than vein M (Becker-Migdisova 1985); cell m 1 elongated, longer than cell cu 1.

At present, six species from Karatau in Kazakhstan and Daohugou in China have been described within this genus. Poljanka curticapillata Lü, Luo & Yao , sp. nov. can be distinguished from four species reported in Karatau by the following characteristics: apical flagellum divided into many small subsections, forewing length 3.85–4.25 mm, both margin and veins of forewing with setae, R forked more distally than the fork in M + Cu 1, Cu 1 forked into curved Cu 1a and Cu 1b and the branches form a right angle, and basal tarsomere longer, about 2.11 times as long as apical tarsomere in hind leg. The new species shares many similarities with Poljanka hirsuta Yang et al., 2012 , and Poljanka strigosa Yang et al., 2013 from Daohugou in the flagellum apically divided into numerous subsections, the labium straight, long, three-segmented, both body and veins with setae and a similar forewing venation. However, it differs from the two species from Daohugou in its flagellum composed of 6 slender segments and 1 swollen section divided into multiple small subsections (vs. flagellum is composed of 7 slender segments and 1 swollen apical section divided into multiple small subsections in the two species), segments III–VIII of the antennae decreasing in length progressively (vs. the length of the flagellomeres do not decrease in sequence, and the length of segment VIII abruptly shortens), with gena (vs. without genae), R longer than M + Cu 1 (vs. M + Cu 1 longer than R). Besides, in comparison to Poljanka hirsute , Poljanka curticapillata has basal tarsomere nearly equal in length to the apical tarsomere of the fore and middle legs, while the length of the basal tarsomere is about 2.11 times that of the apical tarsomere in the hind leg (unlike Poljanka hirsute , where the basal tarsomere is significantly longer than the apical tarsomere of the fore and middle legs, and about 2.31 times that of the apical tarsomere in the hind leg). Meanwhile, Cu 1b is curved in Poljanka curticapillata , while it is straight in Poljanka hirsute . Compared to Poljanka strigose , Poljanka curticapillata features a forewing vein with short stiff setae (in contrast to long stiff setae in Poljanka strigose ), a straight R 1 (versus R 1 bent abruptly at the apex), and a Cu 1a /Cu 1b ratio of 3.46–3.63 (as opposed to a ratio of 6.88–7.53 in Poljanka strigose ).

Figures

FIGURE 2. Habitus of Poljanka curticapillata Lü, Luo & Yao, sp. nov. A and B, Photographs of the holotype under alcohol. A, CNU-PSY-NN2023002p. B, CNU-PSY-NN2023002c. C and D, Photographs of the paratype under alcohol. C, CNU-PSY- NN2023003p. D, CNU-PSY-NN2023003c. Scale bars = 0.5 mm.

FIGURE 3. Poljanka curticapillata Lü, Luo & Yao, sp. nov., line drawings of holotype, CNU-PSY-NN2023002pc. A, Body with wings. B, Fore wing. Scale bars = 0.5 mm.