Tingiometra pankowskii, Golub & Heiss, 2020

Golub, Viktor B. & Heiss, Ernst, 2020, Three new species of the lacebug genus Tingiometra from Cretaceous Burmese amber (Hemiptera: Heteroptera: Tingidae: Tingiometrinae), Zootaxa 4767 (4), pp. 531-542 : 532-536

Tingiometra pankowskii sp. nov.

Figs. 2–10 .

Type Material. Holotype female, Figs. 2–4 , BUB-TING-08 (16/19-4), CEHI.

Paratypes: female, Fig. 5 , BUB-TING-08a (16/03); female, Fig. 6 , BUB-TING-08b (15/27); female?, Fig. 7 , BUB-TING-08 c (15/31); male?, Fig. 8 , BUB-TING-08d (17/06), in CEHI .

Note. Paratype 15/27 was formerly regarded and tentatively designated as paratype of T. burmanica ( Heiss, Golub & Popov, 2015) but now recognized to belong to this new species. Paratypes 15/27 and 15/31 are embedded in blocks of transparent artificial resin.

Diagnosis. This new species differs from T. burmanica by much wider discoidal area of hemelytra including five large cells and having 19–22 rows of small areolae at the widest part (vs 3 large cells and 7–8 rows of small areolae at the widest part in T. burmanica ), narrower subcostal area with about 7 rows of areolae at the widest part (vs 10 rows), narrower and rib-like costal area, wider head (0.30–0.52 mm; vs 0.25 mm), pronotum relatively wider (1.30–1.58 times as wide as long; vs 1.33 times), scutellum relatively wider (1.13 times as wide as long; vs about 1.5 times), median carina lower with only one row of areolae or without areolae (vs two rows of areolae in T. burmanica ), The main differences from other new species of Tingiometra secunda sp. nov and yuripopovi sp. nov. are indicated in their descriptions below and in the key to all four Tingiometra species.

Note. The position of the holotype and paratypes in the amber pieces are different. In addition, specimens of the type series show morphological differences as an evidence of intraspecific variability. Therefore, the description of the holotype and the morphological features of the paratypes are treated separately.

Description of holotype ( Figs. 2–4 ). Body elongate, oval, about 2.54 times as long as wide, hemelytra with rows of very small areolae separated by carinate veins. Head and anterior part of pronotum (calli) with very small punctuation, which is much larger at posterior part. At least head dorsally and femora covered by very short, light, adhering and slightly raised hairs.

Head 2.53 times as long as wide across eyes counting the length of the head from apex of clypeus to posterior margin of eye and 2.77 times counting the length of the head from apex of clypeus to the posterior margin of the frons. Clypeus long, directed anteriorly, horizontal, separated from cheeks by furrows, with longitudinal and moderately wide crest. Apex of head diamond-shaped expanded. Vertex and frons flat. Lateral margins of postocular portion slightly converging posteriorly. Eyes subglobose dorsally, prominently protruding on the head sides and covering the head laterally and partially ventrally.

Antenniferous tubercles very small, adhering. Antennae long and very thin except thickened segment I, segments III and IV shorter and thinner than II; the whole antenna and its segment II 4.9 and 2.27 times as long as width of head across eyes respectively.

Pronotum strongly widening posteriorly, 1.58 times as wide as long at base; its anterior margin not wider than the posterior margin of head. Anterior pronotal margin distinct, posterior one strongly sinuate. Posterior margin not produced and not overlapping scutellum, which is entirely visible in dorsal view. Lateral pronotal margins straight. Pronotal disk slightly convex, with rather large punctures, very low longitudinal median carina without areolae, consisting of a longer posterior part and a shorter anterior part; both parts of carina separated by transverse impression (poorly visible in holotype due to a deformation of pronotum), posterior part of carina about 3–4 times as long as anterior one. Paranota forming very thin translucent plates with serrate external margin, without distinct areolae (possibly artefact).

Scutellum dorsally entirely visible, large, triangular and completely exposed; 1.13 times as wide as long; its apex straightly cut, distinctly enlarged; surface of scutellum very finely punctate.

Hemelytra submacropterous, not reaching apex of abdomen. Costal area very narrow, with one row of very small areolae. Subcostal, discoidal, and sutural areas distinctly separated by carinate veins. Subcostal area declivous, with about 7 rows of areolae at widest parts, divided by 5 and 6 transverse carinate veins different in both hemelytra. Discoidal area very wide, exteriorly limited by R vein and interiorly limited by Cu vein, with 19 irregular rows of areolae at widest part, divided by longitudinal bent carinate vein (evidently M). Discoidal area is divided into five large cells: external basal and apical cells adjoining to subcostal area and three internal cells (basal, medial and apical) located closer to the longitudinal axis of the body and adjacent to clavus and sutural area of hemelytron; external basal cell the largest. Every large cell of discoidal area contains many small round areolae. Sutural area at the base narrow, with 1–2 rows of areolae, posteriorly broaden and with about 6 rows of areolae at apex. Reduced apical half of sutural area is part of hemelytral membrane. Clavus distinct, with 7 rows of areolae at widest part, commissure longer than scutellum. The total surface of discoidal and sutural areas and clavus nearly flat. Venation of posterior wings is unclear.

Venter. Bucculae very short (laterally seen), occupying only the apex of head ventrally, closed anteriorly, surrounding the base of labium like a cover. Labium 4-segmented, its apex reaching metasternum. Sternal thoracic plates absent. Metepisternum with long curved groove possibly representing peritreme of the opening of the scent gland apparatus. The posterior margin of metasternum with a process, which narrows to the apex and reaches metacoxae. Abdominal sternites II and III completely fused, sternites IV–VIII separated by transverse furrows, sternite VII has two (1+1) narrow lateral projections directed posteriorly. Segment IX is located unusually over the segments VII and VIII and only dorsally visible.

Legs long and slender (details of the legs structure of the holotype are not visible).

Measurements of holotype (in mm). Body length 3.00; body width 1.18 (hemelytra slightly apart); head length from apex of clypeus to posterior margin of eye; head length including postocular portion 0.83; length of anteocular portion 0.40; length of eye 0.15; length of postocular portion 0.28; head width across eyes 0.30; width of anteocular part of head 0.125; width of postocular part (approximately, due to an oblique placed head in the piece of amber) 0.20; length of antenna 1,48; length of antennal segments (I, II, III, IV) 0.14, 0.68, 0,23, 0.43; pronotum length 0.43; pronotum width (approximately, due to an oblique placement in the piece of amber and its deformation) 0.68; scutellum length 0.30; scutellum width 0.34; hemelytra length 1.75; width of one wing 0.55; length of commissure between clavus and corium 0.70; length of anterior femora approximately 0.68; hind tibia approximately 1.50 (other segments of legs cannot be measured due to their oblique arrangement in the piece of amber).

Morphological peculiarities of paratypes

Paratype 16/03 (female; Fig. 5 ). Body glabrous, completely hairless.

Head 1.38 times as long as wide across eyes counting the length of the head from apex of clypeus to posterior margin of eye, and 2.05 times counting the length of the head from apex of clypeus to the posterior margin of the frons. The whole antenna and its segment II 4.1 and 1.87 times as long as width of head across of eyes respectively.

Pronotum 1.4 times as wide at base as long. Lateral pronotal margins noticeably sinuate. Paranota rather narrow, slightly reflexed, in the form of very thin, semitransparent plates, with two rows of small areolae at anterior half and with one row at posterior half. Scutellum1.61 times as wide as long.

Hemelytra submacropterous, covering apex of abdomen and noticeably protruding posteriorly. Subcostal area of hemelytra divided by 4 transverse carinate veins. Discoidal area with 20–22 irregular rows of areolae at widest part. Clavus with 6 rows of areolae at widest part.

Venter. Apex of labium reaching middle coxa. A narrow, slightly curved groove runs along the meso-metapleural junction, possibly representing peritreme of the opening of the scent gland apparatus. Sternite VII has a median and 2 (1+1) lateral projections directed posteriorly; median projection (not clearly visible) triangular, with a wide base, lateral projections have a wide triangular base continuing in a long narrow process pointed at the apex. Median projection represents the subgenital plate of segment VII ( Drake & Davis, 1960; Heiss et al., 2015), but the suture between the plate and the basal part of the segment VII is not visible.

Legs long and slender, femora and tibiae cylindrical; tarsi two-segmented, claws thin and long, pulvilli not discernible.

Paratype 15/27 (female. Fig. 6 ). Body glabrous.

Head. Crest on clypeus surface narrow. Eyes very large, covering the sides of the head and partly its ventral surface. Ventral surface of head from base of bucculae to almost anterior margin of eyes with low carina. Posterior margin of pronotum almost right, provided with a very narrow strip bearing one row of very small areolae. Long groove extending along the anterior margin of the left metepisternum is apparently an external groove (peritreme) of the opening of the scent gland apparatus.

Posterior wings. Wings widely spread. Venation of posterior wings as follows: vein Sc is not visible apparently due to its location very close to the costal margin or because of a deformation of the anterior margin of the wing. Vein R is located very close to costal margin in the basal half of the wing and merges with M forming RM in the apical part of the wing. Long Cu located posteriorly, extending to almost wing apex. Short and apical dichotomous branching vein forming two weakly expressed veins are located closer to the posterior margin of the wing. These veins are the secondary ones apparently (SV; after Drake & Davis, 1960). Lateral processes of sternite VII extend beyond posterior margin of sternite VIII, so they are visible when viewing this paratype dorsally. Apex of labium reaches hind coxae.

Paratype 15/31(female? Fig. 7 ). Body glabrous, 2.42 times as long as wide. Subcostal area of hemelytra divided by 6 transverse carinate veins. Discoidal area with about 18 rows of areolae at widest part, sutural area with 6 rows of areolae at the apex, clavus with 7 rows of areolae. Apex of labium reaches hind coxae.

Paratype 17/06 (male? Fig. 8 ).

Head. Crest of clypeus rather wide, postocular lobes clearly tapering toward base. Posterior margin of head with two lateral and one medial elongate process pointed posteriorly. Visible ocellum near posterior margin of right eye (it is possible, however, that we are dealing with an artifact).

Pronotum 1.47 times as wide at base as long.

Hemelytra. Subcostal area with 6 rows of areolae at widest part, divided by 4 transverse carinate veins. Discoidal area with about 18 rows of areolae at widest part. Sutural area with 6 rows of areolae at widest part. Clavus with 7 rows of areolae.

Notes. Legs of all paratypes are long and slender, femora and tibiae cylindrical; tarsi two-segmented, claws thin and long, pulvilli not discernible.

Paratype 7303-1 ( Figs. 9, 10 ) does not have any different specific features.

Measurements of paratypes (in mm). Body length to apex of hemelytra 3.10 (paratypes 16/03, 15/31); body width with wings folded in repose 0.90 (paratype 17/06), 1.28 (paratype 15/31); 2.42 times as long as width (paratype 15/31); head length from apex of clypeus to posterior margin of eye 0.50–0.54; head length including postocular portion 0.73–0.80; length of anteocular portion 0.30–0.43; length of eye 0.10–0.14; length of postocular portion 0.23–0.25; head width across eyes 0.33–0.52; width of anteocular part 0.13–0.175, width of postocular part 0.25–0.34; length of antenna 1.56 (paratype 16/03); length of antennal segments (I, II, III, IV) 0.13, 0.71, 0.28, 0.45 (paratype 16/03); pronotum length 0.43–0.50; pronotum width 0.63–0.70; scutellum length 0.28–0.38; scutellum width 0.29–0.45; hemelytra length 1.78–2.10; length of commissure between clavus and corium 0.70–0.80, femora length: fore 0.70–0.75, middle 0.70–0.75, hind 0.98–1.13; tibiae length: fore 1.20–1.25, middle 1.00–1.20, hind 1.38–1.50; tarsi length 0.13.

Etymology: This species is dedicated to Mark Pankowski (Rockville, Maryland, USA), who acquired the inclusion of paratype 15/27 and generously donated it to the second author for the description.

Distribution. Burmese amber, northern Myanmar.

Figures

FIGURES 1–4. 1, Tingiometra burmanica Heiss et al., 2015, holotype, dorsal view 2–4, Tingiometra pankowskii sp. nov., 2, holotype female (16/19-4), dorsal view, 3, holotype female (16/19-4), head and pronotum, 4, holotype female (16-19-4), pronotum and hemelytra. Scales: 1mm (1,2), 0.5mm (3,4).

FIGURES 5–8. Tingiometra pankowskii sp. nov., 5, paratype female (16-03), dorsal view, 6, paratype female (15/27), dorsal view, 7, paratype female (?) (15/31), dorsal view, 8, paratype male (?) (17/06), dorsal view. Scales: 1mm.

FIGURES 9–12. 9,10 Tingiometra pankowskii sp. nov., 9, paratype male (?) (7303-1), dorsal view, 10, paratype male (?) (7303-1), ventral view; 11, Tingiometra secunda sp. nov., holotype female (16/19-2), dorsal view; 12, Tingiometra yuripopovi sp. nov., holotype female (18/25), dorsal view. Scales 1mm.