Parorectis arenaria Riley, 2020

Riley, Edward G., 2020, A new species of Parorectis Spaeth from the north-central United States, with notes on prothoracic and head morphology of the genus (Coleoptera: Chrysomelidae: Cassidinae: Cassidini), Insecta Mundi 2020 (808), pp. 1-9 : 3-7

Parorectis arenaria Riley , new species

( Fig. 1–21 , Map 1 )

Holotype ( Fig. 1 ). Sex undetermined, labeled “S. DAKOTA: Bennett Co. | 10 mi. N Merriman | (Nebraska) on Hwy. 73 | 43°03.382 ′ N; 101.42.108 ′ W | VII-3-2006, E. G. Riley || [red label] HOLOTYPE | Parorectis | arenaria | Riley”. Deposited in TAMU. The holotype is in excellent condition, not dissected, with all appendages intact.

Paratypes (Total 50). MINNESOTA: Clay Co., 3 mi. E, 2 mi. S Felton, 47°02.77 ′ N 96°25.24 ′ W, Tsct FLT B-B123 b-bl, VII-13-2000, P. B. Beauzay, sweep on mesic prairie [1 NDSU]. NEBRASKA: Cherry Co., 2.9 mi. N Merriman on Hwy. 61, VI-29-1992, E. G. Riley [1 EGRC]; same data except, reared from late-instar larvae taken on Physalis sp. [2 EGRC]; 17 km. E Merriman, 42.9215°N, 101.4947°W, reared from larva; adult reared from larva collected on VI-25-2018, E. G. Riley, on Physalis hispidus (Waterf.) Cronquist [9 EGRC]. Sheridan Co., 10 mi. E Alliance, 3600 ft., 42.0765°N, 102.6746°W, VII-14-2016, A. J. Gilbert [1 AJGC]; Trail 358, 7.5 km. E Hwy. 250, 43.3592°N, 102.3385°W, VI-23-2018, E. G. Riley, on Physalis hispidus (Waterf.) Cronquist [1 EGRC]. SOUTH DAKOTA: Bennett Co. same data as holotype [7 EGRC, TAMU]; 12.5 (rd.) km. S Martin on Hwy. 73, 43.0661°N, 101.7031°W, VI-27-2016, E. G. Riley, sandhills [1 EGRC]; same data, except collected as larva on Physalis sp. [1 EGRC]; 11 km. N Merriman (Nebraska), 43.0179°N, 101.7022°W, reared from larva; adult reared from larva collected on VI-24-2018, E. G. Riley, on Physalis hispidus (Waterf.) Cronquist [20 AJGC, BYUC, EGRC, TAMU, USNM]. WISCONSIN: Columbia Co., T 12N R 8E Sec. 32, VIII-9-1997, A. H. Williams, feeding on leaf of Physalis heterophylla , 4 PM, hazy, 80°F [1 UWRC]. Dane Co., Walking Iron Prairie, T 8N/ R 6E/Sec.8NW, VI-22-1995, R. A. Henderson, DNR study 053 [1 UWRC]. Grant Co., Hwy. 133, sandy prairie, T 8N R 3W Sec.24, VII-8-2001, A. H. Williams, spiny pupa, with dung on “tail”, atop leaf of Asclepias viridiflora , adult emerged July 16 [1 teneral, UWRC]. Sauk Co., Green Spring Prairie –E, T 8N/ R 4E/Sec.6NE, V-31-1996, R. A. Henderson, DNR study 053 [1 UWRC]; Green Spring West, T 9N R 3E S35/NE, VII-22-1997, DNR study 053, sweep net [1 UWRC]. WYO- MING: Platte Co. Glendo, VI-1-1961, R. J. Lavigne [1 USNM].

Description. General. Oblong, subparallel-sided in dorsal view, broadly arched in lateral view with dorsal crest at approximately midlength of body. Body length 4.8–6.4 mm (avg. = 5.55, n = 12), greatest width more-or-less at midlength of body 3.6–4.56 mm (avg. = 4.15, n = 11). Color (non-teneral, non-reared specimens). Dorsum yellowish-brown; pronotum with pair of small, round, black spots near center of disc, variable in size, rarely irregular in shape; elytral disc with faint dark smudge on largest swelling on second interval; explanate margins of pronotum and elytra with small semi-transparent cells. Venter brownish-yellow, except metasternum on each

side usually with large brownish smudge faded toward margins. Terminal three or rarely terminal two antennomeres dark brown to black; legs pale.

Form. Head. Clypeus flat with faint medial impression and lateral grooves, surface shagreened, base ill-defined laterally and at basal corners ( Fig. 2 ). Dorsum of cranium with longitudinally elongated fusiform pars stridens at base in male ( Fig. 3, 4 ), absent in female; round binding patch present, positioned centrally in both sexes, anterior to pars stridens of male ( Fig. 3, 5 ). Eyes moderately large, not especially bulging, length of genal space subequal to maximum width of antennal scape. Antenna moderate in length, exceeding lateral pronotal margin by terminal two antennomeres; pedicle (antennomere II) shorter than III, nearly as wide as scape; first two flagellar segments (antennomeres II–IV) slightly longer and narrower than last two flagellar segments (antennomeres V–VI); terminal antennomeres commencing with antennomere VII, formed into a weak antennal club ( Fig. 14 ). Pronotum. Wider than long (avg. W/L ratio1.66, n = 12); anterior margin and lateral margins broadly and evenly rounded; posterior margin shallowly emarginate on each side before short, median truncate lobe. Surface impunctate, shining to finely shagreened; disc transverse, with broad anterolateral lobe on each side; margin with evenly distributed, closely spaced, semi-transparent cells; extreme margin with no apparent marginal bead. Elytra. Subparallel, broadly, evenly rounded distally. Each elytron with basal margin finely crenulate from near scutellum to beyond humeral umbo ( Fig. 6 ), humeral umbo prominent; disc punctate striate, with 10 more-or-less well developed striae, slightly irregular over central portion of disc; punctures of striae large and deep, separated on average by spaces roughly equal to their diameters; punctures of outermost stria larger and transverse; sutural interval and interval II slightly elevated, other intervals slightly expanded and elevated at various points, especially near dorsal crest where a weakly raised transverse elevation partially disrupts regularity of striae I and II. Explanate margin broad, moderately deflexed anteriorly, horizontal and extended shelf-like at apex, with semi-transparent cells as in pronotal margin; surface impunctate, uneven, shiny; anterolateral corner right-angled, blunt; extreme marginal bead well-developed, strong to apex; internal ridge of epipleuron meets suture before elytral apex. Venter. Prosternum with apex moderately expanded post-coxae, apex bluntly rounded; surface weakly impressed, irregular; metasternum and abdominal ventrites smooth, shining. Legs. Tarsomere IV mostly embedded in lobes of tarsomere III ( Fig. 15 ). Claws divergent, each claw simple, ventral basal angle of claw rounded ( Fig. 21 : BA). Pectens of meso- and metatarsal claws symmetrical sensu Riley (1986) ( Fig. 13 , 21 : PE). Genitalia. Male genitalia in en-face view spatulate with subtruncate tip ( Fig. 16 ), shaft of median lobe evenly weakly bowed in lateral view ( Fig. 17 ); endophallus not studied. Female sternite VIII (internal) with sclerotized portion cross-shaped, lateral arms narrow; each side with broad membranous fenestra; distal margin transverse, with distinct fringe of long setae; basal stem short and broad ( Fig. 19 ). Female genitalic tract with spermathecal duct frail, tightly coiled, long, composed of ca. 133–149 coils, avg. = 140 (n = 3) ( Fig. 18 ); spermatheca simple, c-shaped, with terminal appendix ( Fig. 20 : AP).

Comparative remarks. The new species is separated from P. callosa and P. rugosa by obvious differences in body coloration and shape. These two species are much more strongly arched in profile and the elytral discs sport a mix of distinctly elevated large and small tubercles. Also, the elytral discs of these two species are dark, with that color extended anteriorly and posteriorly onto the semi-transparent explanate margins and reaching the extreme elytral edges. The new species is most similar to P. sublaevis which is uniformly yellowish-brown above but lacks the pair of black spots on the pronotal disc, dark smudges on the elytral disc and dark smudges on the sides of the metasternum. The elytral punctation of P. sublaevis is more crowded than in the new species, and it is also smaller in body size, ranging in length from 4.72 to 5.6 mm (avg. 5.13 mm, n = 16).

Some of the reared specimens possess a greater amount of darkening of the raised elytral areas, this often extended over most of the disc. This more extensive darkening is thought to be in some way related to the rearing environment, as this color variation is not seen in any of the wild-caught adult specimens.

Etymology. This species is named for its association with sandy habitats, its name derived from arena, Latin for sand. Gender feminine.

Range. North-central United States ( Map 1 ). One additional specimen (non-paratype) is known through examination of a website photo. This specimen is misidentified as Deloyala guttata (Olivier) in the photo gallery of insect specimens collected from Cedar Creek Ecosystem Science Reserve near East Bethel, Minnesota ( Haarstad 2002). This locality is plotted on Map 1 along with localities from the specimens examined.

Biological remarks. Andrew H. Williams (in litt. to EGR) describes the known Wisconsin localities as “sand prairies.” The Cedar Creek Minnesota locality includes sand prairie, savanna and other habitat types ( Haarstad 2002). The Nebraska and South Dakota localities are part of the Sandhill Region of these states, the largest sand dune system in North America consisting mostly of dunes stabilized by the sandhills mixed-grass prairie type ( Bleed and Flowerday 1990; Joern and Keeler 1995). All specimens collected by the writer were taken in this region at localities of deep sand and were associated with Physalis (Solanaceae) , either by rearing larvae to adults or by collecting adults from this plant. Associated Physalis specimens were later identified as P. hispidus (Waterf.) Cronquist. One of the Wisconsin specimens was observed feeding on a leaf of Physalis heterophylla (A. H. Williams label data). The examined Minnesota specimen is labeled as having been taken by sweeping mesic prairie. Living adults are non-metallic. Larvae are unremarkable in general appearance, being pale greenish in life, with semi-transparent lateral scoli.

Figures

Map 1. Known distribution of Parorectis arenaria, new species, based on specimens examined and Haarstad (2002) (see text).

Figures 1–8. Parorectis arenaria new species 1) Holotype and holotype labels. 2) Male head, face. 3) Male head, dorsum of cranium: BP = cephalic binding patch, PS = pars stridens. 4) Pars stridens. 5) Cephalic binding patch. 6) Base of pronotum and anterior margin of elytron. 7) Anterior prothoracic foramen with head removed, ventral view: AG = antennal groove, CFR = circum-foraminal ridge, LR = lateral ridge, PC = prosternal collar, PL = plectrum. 8) Anterior prothoracic foramen with head removed, ventrolateral view.

Figures 9–13. Parorectis arenaria new species, scanning electron microscopy images. 9) Anterior prothoracic foramen with head removed, ventral view. 10) Anterior prothoracic foramen with head removed, ventrolateral view: AG = antennal groove, CFR = circum-foraminal ridge, LR = lateral ridge, PC = prosternal collar, PL = plectrum. 11) Plectrum. 12) Spicules of cephalic binding patch. 13) Mesotarsal claws, lateral view: PE = pecten.

Figures 14–21. Parorectis arenaria new species, body parts. 14) Male antennae. 15) Male protarsus, lateral and dorsal. 16) Male genitalia, en-face view. 17) Male genitalia, lateral view. 18) Female genitalia tract and pygidium. 19) Female sternite VIII. 20) Spermatheca and adjacent duct: AP = appendix. 21) Male mesotarsal claws, exterior and interior surfaces of posterior claw on left, interior and exterior surfaces of anterior claw on right: BA = basal angle, PE = pecten.