Megatibicen pronotalis hesperius, Sanborn, 2025

Megatibicen pronotalis hesperius n. ssp. ( Fig. 2 View FIGURE 2 )

Tibicen pronotalis walkeri Sanborn & Heath 2012: 69 View in CoL (in part), 70, Fig. 72.

Tibicen pronotalis walkeri Sanborn & Phillips 2013: 171 View in CoL , Table 1 View TABLE 1 , 193, Fig. 21 (in part).

Neotibicen pronotalis walkeri View in CoL (Texas specimen) Hill et al. 2015: 233, Fig. 2 View FIGURE 2 , 234, Fig. 3 View FIGURE 3 , 235, Fig. 4 View FIGURE 4 , 236, Fig. 5 View FIGURE 5 , 238, Fig. 6, 248, Appendix.

Megatibicen pronotalis walkeri Sanborn et al. 2017 View in CoL : ix, Table 2 View TABLE 2 (in part).

Megatibicen pronotalis walkeri Sanborn & Heath 2017b: 84 View in CoL (in part), Fig. 55.

Megatibicen pronotalis walkeri Sanborn et al. 2021 View in CoL : Supplementary Table 1 View TABLE 1 (in part).

Megatibicen pronotalis View in CoL “Western” form Kratzer 2024: 101.

TYPE MATERIAL.— Holotype. “ TEXAS GOLIAD COUNTY / US 59 6.0 mi E of Goliad / 22 June 1994 / A. Sanborn coll.” male ( FSCA) . Paratypes. Same data as holotype, one male and two females ( AFSC); “ TEXAS GOLIAD COUNTY / US 59 6.0 mi E of Goliad / 22 June 1994 / A. Sanborn, P. Phillips coll. // recorded specimen” two males ( AFSC); “ TEXAS GOLIAD COUNTY / US 59 6.0 mi E of Goliad / 22 June 1994 / A. Sanborn, P. Phillips coll.” one female ( AFSC) .

ETYMOLOGY.—The name hesperius (L. western) is in reference to the form name given by Kratzer (2024) for the population and its geographic distribution.

DIAGNOSIS.—The new sUBspecIes Is lArger thAn Both M. pronotalis pronotalis rev. stat. and M. pronotalis walkeri rev. stat. (see comparative measurements in Table 2 View TABLE 2 with all measurements of the proposed new subspecies being different statistically with P<0.0001 in all cases) and can be distinguished by these measurements. In addition, the new subspecies lacks the large piceous marking on the dorsal prothorax midline found in M. pronotalis pronotalis rev. stat., and the fore wing basal cell is about 1.93 times longer than broad (about 2.13 times in the new subspecies). The new subspecies can be distinguished from M. pronotalis walkeri rev. stat. by the straighter fore wing costal margin, the expanding distal fore wing apical cell 2, the proportionately longer fore wing apical cell 8 and ulnar cell 2, ulnar cells 1 and 2 are approximately the same length, the broader distal portion of ulnar cell 3, the radial and radiomedial crossveins are not parallel and the curving mediocubital crossvein, the fore wings are about 2.71 times longer than wide in the new subspecies but about 2.79 times longer than wide in M. pronotalis walkeri rev. stat. (and these values differ statistically t=4.013, d.f.=12, P=0.022), and the fore wing basal cell is about 2.13 times longer than broad in the new subspecies rather than about 2.22 times longer than broad in M. pronotalis walkeri rev. stat.

Description

Ground color greenish tawny (fading to tawny with age), head, mesothorax and abdomen marked with piceous, head and abdomen also marked with castaneous. White pruinosity present on mesothorax and abdomen, dense in some specimens.

Head

Head wider than mesonotum, ground color with transverse piceous fascia between eyes encompassing ocelli, mark expands medially anteriorly to frontoclypeal suture and posteriorly to posterior head, ground color marks on either side of midline anterior to median ocellus, in posterior epicranial suture, lateral to lateral ocelli, and medial to posterior cranial depression, lateral mark extends anteriorly along eye margin to level of anterior lorum, piceous fascia on posterolateral eye extending laterally to middle of eye, piceous fascia on posterior head between lateral posterior cranial depression and middle of eye forming a ground color transverse fascia on posterolateral head and posterior to eye. Supra-antennal plate ground color with curved medial margin, anterior curve extends over anterolateral corner of postclypeus. Covered with short golden pile dorsally, denser in sutures, longer silvery pile posterior to eye. Ocelli rosaceous, eyes castaneous. Ventral head ground color, transverse piceous mark on gena between eye and postclypeus, lorum ground color with piceous posteromedial spot, expanding on lorum or central lorum lightly castaneous in some paratypes. Thick white pubescence and long, radiating white pile on lorum and gena. Postclypeus not sulcate, primarily castaneous, dorsal surface piceous on either side of ground color midline, piceous extends into dorsal transverse grooves, elongated ground spot on anterior half of ventral midline, darkening along posterior midline and posteroventral margin, transverse ridges ground color on anterior side, castaneous on posterior side. Postclypeus with thirteen transverse grooves, short golden pile on dorsum, thick white pubescence and long silvery pile on lateral postclypeus. Anteclypeus ground color with castaneous carina, ground color or only posterior half castaneous in some paratypes, and castaneous spots on anterolateral corners, posterolateral corners piceous, covered with thick white pubescence and long silvery pile. Mentum ochraceous, labium ground color with medial castaneous stripe, darkening to piceous tip reaching to posterior of middle trochanters with sparse short and long silvery pile. Antennal segments castaneous.

Thorax

Dorsal pronotum ground color with triangular piceous mark on either side of anterior midline, piceous within paramedian fissure, incomplete in some paratypes, small transverse piceous fascia on either side of dorsal midline anterior to ambient fissure. Pronotal collar ground color. Pronotum covered with short silvery pile, denser in fissures and on lateral pronotal collar. Mesonotum tawny, submedian sigillae piceous with small tawny longitudinal fascia near midline, reduced to small spot in some paratypes, anterior half of parapsidal suture castaneous, lateral sigillae piceous with broad, angled tawny posterolateral fascia, mark expanded in some paratypes almost filling lateral sigillae in one paratype, piceous between anterior arms of cruciform elevation with mark extending anteriorly along midline terminating between submedian sigillae, mark extends posteriorly onto anteromedial cruciform elevation and across anterior portion of anterior arms of cruciform elevation, piceous forms the upside down ground color “resh”- shaped mark characteristic of the genus, cruciform elevation tawny with light castaneous laterally between anterior and posterior arms, wing groove tawny with piceous anteromedial margin and castaneous spots on anteromedial and anterolateral corners. White pubescent spot on anterolateral and lateral margin of mesonotum and in anterior wing groove. Metanotum tawny with castaneous anterior margin, completely tawny in some paratypes. Long, dense silvery pile on mesonotum, denser on anterior margin, laterally and posteriorly and between arms of cruciform elevation, in wing groove, and on posterior metanotum. Ventral thoracic segments with thick white pubescence and long white pile, tawny with castaneous basisternum 2 and 3, piceous katepisternum 2 and central anepimeron 2.

Wings

Fore wings and hind wings hyaline with eight and six apical cells respectively. Fore wings about 2.71 times longer than wide. Venation ground color, veins between apical cells darker in some paratypes, piceous ambient vein in apical cells 2–4 in both fore wing and hindwing, fore wing costal margin almost straight to node. Basal cell clouded except along cubitus anterior and branch to arculus, about 2.13 times longer than broad. Pterostigma to terminus of radius anterior 1. Distal fore wing apical cell 2 expands, fore wing apical cell 8 and ulnar cells 2 longer than in other subspecies, ulnar cells 1 and 2 approximately the same length, distal portion of ulnar cell 3 broader than in other subspecies, radial and radiomedial crossveins not parallel as in other subspecies, mediocubital crossvein sinusoidal. Basal membrane of fore wing ground color speckled with orange. Hind wing with proximal two-thirds of and distal margins of anal cell 3, anal cell 2 along anal vein to curve, anal cell 1 and 2 along anal vein 2, and posterior to proximal two-thirds of cubitus posterior vein ground color, white section along distal medial margin of anal cell 3.

Legs

Coxae, trochanters, and femora tawny. Fore femora with proximal spine almost perpendicular to long axis, longest, secondary spine obliquely angled to long axis, more triangular in shape, and small, slightly angled, triangular tertiary spine, all tawny, primary and secondary spine with castaneous tips. Tibiae castaneous with proximal tawny end, tarsi castaneous. Pretarsal claws ochraceous with piceous tips, tibial spurs and comb castaneous with piceous tips. Segments radiating golden pile, longer in distal segments. Meracanthus pointed, dark tawny with castaneous base not reaching to middle of operculum, reaching to level of proximal hind trochanter. Female meracanthus longer than operculum reaching to middle of sternite II, dark castaneous lightening distally.

Operculum

Male operculum large with semi-circular posterior margin, overlapping medially, reaching to the edge of the tympanal cavity on anterior of sternite II, tawny with piceous spot on anterolateral base, covered with dense white pubescence. Female operculum with medially angled lateral margin, rounded posterolateral margin forming an approximate right angle, sinuate posterior margin, terminating medially at lateral meracanthus, reaching to anterior of sternite II, tawny with piceous spot on anterolateral base and castaneous anteromedial region, covered with thick white pubescence. Female opercula with long white pile radiating from edge.

Abdomen

Abdominal tergites piceous, tergites 2–8 with castaneous posterior margin, castaneous expanding on lateral regions of tergite 8, covered with short silvery pile, longer along anterior tergite 1, white pubescence laterally and forming a row of spots on dorsal tergite midline, more obvious in paratypes. Timbal cover tawny with white pubescence, completely concealing timbal, extending anteriorly beyond anterior of abdominal segment 1, slightly inflated from margins but with flat surface, ventral margin straight and parallel to operculum. Female abdominal segment 9 ground color with castaneous triangular mark on dorsal surface, piceous dorsolateral anterior margin becoming angled fascia to piceous dorsal beak forming castaneous triangular mark, piceous extends ventrally through stigma recurving and becoming short castaneous fascia, tawny ventrally and posteriorly, with short silvery pile on surface and dense, long, golden pile along ventral side and near posterior, white pubescence on anterolateral surfaces and covering area of stigma in some paratypes. Posterior margin of abdominal segment 9 sinuate. Sternites tawny except castaneous middle of sternite I, transverse castaneous fascia on sternite II, longitudinal piceous mark between posterior sternite II and anterior of sternite III. Epipleurites tawny with castaneous lateral margin, posterior margin and central castaneous spots in some paratypes. Female sternite VII with single, open V-shaped medial notch, light castaneous spot laterally. Sternites and epipleurites with white pubescence, very dense laterally, and radiating long silvery pile.

Genitalia

Male pygofer piceous anteriorly and dorsally, piceous margined with castaneous, tawny ventrally and along posterior margin except for piceous midline, tawny pygofer basal lobes, with rounded distal shoulder, dorsal beak very small. Pygofer basal lobe distinctive, long, triangular with rounded apex, angled laterad forming large V-shaped notch, radiating long golden pile, pygofer upper lobes ill-defined. Anal styles castaneous with tawny base, anal tube tawny with dark castaneous ventral margin. Median uncus lobe dark castaneous, triangular, flanked by finger-like lateral uncus lobes converging to rounded posterior terminus, laterally expanded at tawny base, curving ventrally distally, flattened along ventral midline to support aedeagus. Aedeagus tubular, dark castaneous.

Female gonapophyses VIII dark castaneous, gonapophysis IX dark castaneous with piceous tip, gonapophysis X ground color at base becoming dark castaneous distally, gonaophyses extend beyond dorsal beak with radiating golden pile. Gonocoxite IX tawny. Anal styles castaneous margined with ground color at base.

MEASUREMENTS (MM).—N = foUr mAles or three femAles, meAn (rAnge). Length of BodY: mAle 40.86 (40.00– 42.55), female 42.98 (41.10–44.75); length of fore wing: male 54.28 (53.60–55.60), female 55.88 (53.40–57.40); width of fore wing: male 20.00 (19.30–20.40), female 20.67 (19.70–21.20); length of head: male 6.66 (6.30–7.00), female 7.03 (7.00–7.10); width of head including eyes: male 17.60 (16.95–17.60), female 18.12 (17.65–18.80); width of pronotum including suprahumeral plates: male 18.04 (17.40–18.60), female 18.80 (18.00–19.55); width of mesonotum: male 15.64 (14.95–16.20), female 16.60 (16.10–17.35).

DISTRIBUTION.—DefInItIve exAmples of the new specIes Are known from GolIAd And JAckson CoUntIes, TexAs. Kratzer (2024) describes the “Western” form extending from the Gulf coast of Texas north to southern Nebraska. However, many of these records are based on photographs and specimens need to be examined to determine their species status. Sanborn & Phillips (2013) describe M. pronotalis walkeri rev. stat. as inhabiting two different biomes. It may be that M. pronotalis walkeri rev. stat. and M. pronotalis hesperius n. ssp. are separated into these two biomes as the distribution of the two forms in Kratzer (2024) closely follows the plant communities.