Abachrysa eureka

Part 2. Redescription of Abachrysa eureka (Banks, 1931)

(Figs. 6, 12–22)

Taxonomic Synonymy (selected references).

Chrysopa eureka Banks, 1931, Psyche 38: 174; “Hope, Ark., 22 Aug. (L. Knobel), at light”. Holotype in Museum of Comparative Zoology”; only one specimen mentioned, sex unknown, not examined.

Abachrysa eureka (Banks). Banks 1938: 75 [new combination, designated type species of new genus Abachrysa Banks]. Brooks & Barnard 1990: 164-5, 266 [redescription, figures]; Garzón-Orduña et al. 2019 [phylogeny within Neuroptera]; Winterton et al. 2019 [phylogeny within Neuroptera]; Tauber et al. 2020: 481 [description of first and third instars, images, biology, myrmecophily, evolutionary considerations].

Diagnosis. Abachrysa eureka is distinguished from other New World belonopterygines by its fairly large, robust body and distinctive markings; head gold, without markings, except pedicel black, flagellum mostly black, only distal ¼ pale; labial and maxillary palpi black distally; venter of thorax and abdomen heavily marked with black spots throughout; legs pale, except tarsal tips, tibial bases, femoral tips black. Forewing somewhat narrow, with most or all veinlets reaching posterior margin forked (except 3A and 1–2 small veinlets). Male genitalia with large, paired, elaborate parameres; female with praegenitale (sensu Tjeder 1966) tubule-like, looping externally from base to tip of subgenitale.

Redescription. Head. (n=3; Figs 12 & 13). Width (frontal, including eyes) 2.3–2.4 mm; ratio of head width to eye width = 4.1–5.0: 1; width between tentorial pits 0.72–0.73 mm; length mid-antenna to midway between tentorial pits 0.55–0.73 mm; length midway between tentorial pits to tip of clypeus ~ 0.60–0.65 mm. Scape with lateral margin straight, mesal margin slightly rounded; vertex rounded, raised posteriorly, with surface smooth, shiny. Frons smooth, shiny, with large torulli; epistomal suture slightly convex with slight transverse fold below. Clypeus with surface transversely striated, distal margin indented. Labrum rounded laterally, not withdrawn; distal margin deeply indented mesally. Antennal length 12.9–13.6 mm (n=2 from one specimen); scape slightly wider than long; basal flagellomeres (#2-#6) with length 0.13–0.16 mm, width 0.15–0.17 mm, ratio of length to width = 0.87–0.93: 1; flagellomeres (midantenna) of similar length (0.13–0.16 mm), smaller width (0.10–0.12 mm), higher ratio of length to width = 1.2–1.4: 1). Flagellar setae short, brown, positioned in four rings, with consistently fewer setae in fourth ring than in three basal rings; almost all flagellar setae extending distally; each flagellomere with pair of pale laterally projecting setae near edge of distal margin. Mandibles broad, symmetrical, heavy throughout; both mandibles with mesal tooth, with inner margin straight after tooth. Labium with ligula bulbous, bearing numerous stout setae basolaterally, numerous fine setae distally. Maxilla with stipe robust; galea large, greatly expanded distally, extending well beyond labrum in most specimens; all segments densely setose. Coloration: Head gold, without markings. Antenna: scape gold; pedicel, basal ¾ flagellum black; distal ¼ flagellum pale; labrum gold, unmarked. Maxilla with distal three palpomeres black, basal two pale; galea, cardo, stipe pale. Labium with distal palpomere black, middle palpomere black laterally, basal palpomere pale,

Thorax. (n=2; Fig. 14). Robust; pronotum broad, width ~two times greater than length, with small lateral patch of medium-length, pale setae, with sparse, short, dark setae elsewhere; mesonotum, metanotum with relatively few short, dark setae. Legs robust with short, dark setae; mesotibia, metatibia with small, brown spur on distal margin; protibia without distal spur; tarsal subsegments with ventral setae modified as robust spurs along lateral edge; pretarsus with pair of elongate, slender setae, pair of shorter setae; tarsal claws simple, recurved, without quadrate base, with tip not greatly extended beyond base. Coloration: Background cream to amber. Pronotum with four pairs of large, round, dark brown spots, evenly arranged over surface. Membranous region behind prothorax, anterior to wing base, with two pairs of dark brown spots. Mesonotum with prescutum bearing pair of large dark brown spots on frontal margin, posterior margin with single pair of irregularly shaped dark brown spots; scutum with two pairs of brown spots; scutellum gold, without marks. Metanotum with each side of scutum bearing round, dark brown marks above and below; scutellum gold, without marks. Pleural regions cream, each segment with large dark brown spots. Legs light cream, with dark brown setae; femur with dark brown mark distally; tibia with dark brown spot basally, smaller dark lateral spot at ¼ distance from femoral junction (spot also present on metatibia, but sometimes very small); distal tarsomere with dorsal surface dark brown; pretarsus with claws and arolium dark amber to brown.

Wings (n=2; Fig. 15). Forewing length 18.0–19.0 mm, maximum height 5.7–6.1 mm; slightly broad throughout, with tallest portion of wing being about midwing; height at distal end of basal quadrant 4.5–4.9 mm; height midwing 5.6–6.0 mm; height at basal end of distal quadrant 5.3–5.6 mm; anterior margin relatively straight; apex rounded with very slight angulation at tip. Costal area slightly expanded basally; tallest costal cell (c5) 0.20–0.21 times maximum height of wing. Subcosta, radius slightly sinuous to straight; subcosta bordered by abrupt fold basally which tends to obscure view of sc-r crossvein; most costal veinlets, radial crossveins straight or very slightly curved; basal sc-r crossvein ~ 0.35–0.69 mm distal to crossvein between mcu1 and mcu2, slightly more than half the distance to M f. Ten to eleven closed radial cells (rarp), height of tallest radial cell (rarp5) 1.4–1.7 times width. First rp-m crossvein meeting M at first intramedian cell (mamp1); mamp1 triangular in shape, composed of MA, MP, no distal crossvein (therefore true im1 cell), width ~0.55 times width of third medial cell (mcu3); gradate veins in two rows (sometimes with a single additional gradate vein), with five to six inner gradates, six to seven outer gradates, both rows regularly spaced, slightly divergent distally, with last pairs of gradates convergent. Three to four b cells, four to five b’ cells. Three intracubital cells: icu1 usually, but not always longer than icu2; icu3 open distally; CuP forked at icu2. Vein A1 forked. Hindwing fairly broad, with apex rounded; length 16.0– 17.1 mm, maximum height 4.8–5.3 mm. Eleven radial cells (rarp); base of M merged with R, t cell absent; five inner gradates; seven outer gradate veins; three b cells; four 4 b’ cells. Coloration: Forewing, hindwing hyaline, glossy; stigma prominent, white with dark brown suffusion around subcostal crossveins. All longitudinal veins pale with large dark marks at each intersection; most at base of hindwing pale; all veinlets and crossveins dark brown to black; radial crossveins, crossveins below PsM with pale areas mesally; setae dark.

Abdomen—Male. (n=2; Figs 16 –18). Exterior: Texture of integument soft, flexible, with tendency to fold or tear. All tergites, all sternites, pleural region of A8 (only) with short to medium-length, sturdy setae; T9+e with longer, more dense setae. Microtholi present at least on S6–S8. Pleural regions proximal to A8 mostly without setae; spiracles medium-sized, round, simple, with two atria. Tergites (dorsal view) roughly quadrate with rounded corners, almost twice as wide as long; dorsum of T9 short, fully fused with ectoproct, moderately bilobed distally (dorsal view), with dorsal surface entire, slight suggestion of mesal suture; lower margin of T9+e (lateral view) fully lined by slender dorsal apodeme with inverted V-shape; distal leg of V with small hook at terminus, then curving slightly upward, extending along entire ventral surface of T9+ectoproct, below callus cerci, to junction near T8; proximal leg of dorsal apodeme extending anteroventrally well into basal section of A8, ending near proximal peak of S8. Surface between legs of apodeme with long, robust setae similar to those on T9+e. Callus cerci circular (height 0.25 mm, width ~ 0.29 mm), with ~53–54 slender trichobothria. Basal sternites tall, e.g., for S4–S6, ratio of length to height (lateral view) = ~0.82: 1; S7 shorter, ratio of length to height = ~0.75: 1.

Sternites 8 and 9 fully fused, but marked by prominent line of fusion (suture); S8 with short, stout setae, proximal apex slightly lower than adjoining distal margin of S7; S9 with surface smooth, unmarked, bearing longer, finer setae than S8; ventral apodeme visible below dorsal margin of S8&9, sloping through upper region of distal S8, terminating in ventral region of mid-S9. Terminus of S9 relatively broad, straight, smooth, with robust, scabrous membrane folded internally; gonapsis absent, parameres present. Coloration: Cream with dark markings as in Figs 16 and 19. Callus cerci cream with black slash distoventrally.

Genitalia: Parameres elongate, slender, curved, acute tipped, with ~three acute thorns along inner margin, with bases remainng separate in heavy membranous sockets embedded in sturdy, darkened, scabrous membrane extending forward beneath each paramere, attached to robust, clear membrane via pair of brownish, scabrous membranes on tip of S9. Gonarcus rounded, arcuate; gonarcal bridge with quadrate, slightly fluted plate extending from dorsal surface; gonarcal apodemes elongate, broad, rounded distally, each bearing small dorsal protrusion near gonarcal plate; mediuncus attached below gonarcal bridge via heavy membrane; pair of spurs* lateral to gonarcal bridge, not attached directly to gonarcal bridge, but via membranous connection; long, robust, clear membrane holding parameres attached to ventral surface of mediuncus. Mediuncus flat, basally with two rounded wings hollow below; distal margin with small, sclerotized, rounded beak; proximal section bifurcated, with each wing separate. Hypandrium internum relatively large, V-shaped; arms straight, distally curved; dorsal keel slender, shallow; comes spear-shaped, about size of keel. Gonosaccus, gonosetae absent.

*The spurs (Figs 17B, 17C, 17E) mentioned in the lines above are not fused with the gonarcus, nor do they “articulate” with the gonarcus; rather, they are attached to the gonarcus via a membrane. Thus, they do not fall within the definition of either a gonocornu or an entoprocessus (Brooks & Barnard 1990: 124, Sosa & Tauber 2021). Here we use the descriptive term “spur” to identify them.

Abdomen—Female. (n=2; Figs 19–22). Exterior: Texture of integument soft, flexible, with tendency to fold or tear. Tergites (including T9+e) closely aligned but not completely fused dorsally; mesal line of fusion visible. Sternites (S3–S7) with relatively dense, evenly spaced, short setae throughout, becoming slightly longer, more robust posteriorly. Tergites (A3–A8) with longer, less dense, evenly spaced setae, also becoming denser and longer distally. Pleural regions of A3–A6 with few setae; pleural regions of A7, A8 with sparse covering of small setae, becoming larger distally; T9+e, gonapophyses laterales with dense, long setae throughout. Spiracles oblong, large on A5, A6 (length ~ 0.13–0.14 mm, width 0.05–0.06 mm), smaller distally (length ~ 0.08–0.09 mm, width 0.03–0.04 mm), with simple atrium, single small lobe. Tergites, sternites quadrate, with sides curved (flat view), rounded corners. Sternites S4–S6 (lateral view) with length about ¾ times height; S7 (lateral view) with height and length about equal, dorsal margin straight over basal ~one third, sloped to slightly angled over distal two thirds; distal margin of terminus with small mesal indentation. Ninth tergite + ectoproct (lateral view) narrow, with fairly straight, parallel lateral margins dorsally, diverging somewhat throughout; distal margin slightly concave; ventral margin gently rounded; proximal margin sloping slightly (width along ventral margin ~0.5x entire length of T9+e). Callus cerci ~round (height 0.23–0.25 mm, width 0.20 mm), with approximately ~47–51 trichobothria. Gonapophyses laterales slender, slightly crescent shaped in lateral view, curved, forming a circular doughnut shape in ventral view (height ~ 0.95–0.97 mm, width ~ 0.36–0.37 mm). Coloration: Exterior cream to tan, terminal sternites gold; all segments with tergites, sternites, pleural regions marked with bold black bands, spots; callus cerci gold, encircled with fine, dark line.

Genitalia: Internal female genitalia not especially large, contained within abdominal cavity of lower half of T9+e, pleural region of A8. Spermatheca robust, heavily sclerotized, doughnut-shaped structure with moderately deep invagination; spermathecal diameter (maximum) ~ 0.41 mm, height ~ 0.25 mm; invagination depth ~ 0.14 mm; invagination width at mouth ~ 0.12 mm. Dorsal surface of spermatheca with large, well sclerotized, sail-shaped velum extending proximally toward bursa copulatrix; length of spermatheca and velum ~ 0.80 mm; velum distally giving rise to spermathecal duct; basal section of spermathecal duct heavily sclerotized, U-shaped, extending directly into subgenitale, with distal end of U-shaped curve attached to membranous base of subgenitale; distal end of spermathecal duct exiting subgenitale, forming broad curves; sclerotized section of spermathecal duct ~ 1.9 mm long, ending abruptly, leading immediately to narrower, lightly sclerotized, brushy terminal section of spermathecal duct. Brushy, distal section of spermathecal duct forming ~half length (~ 1.7 mm) of entire duct. Dorsal surface of spermatheca, velum, and sclerotized section of spermathecal duct with broad, elongate slit opening into bursa copulatrix above. Bursa copulatrix consisting of robust membrane with fluted, coiled section basally, large, clear, sac-like distally; base of sac-like section with pair of elongate, narrow, ribbon-like bursal glands. Subgenitale with (i) broad basal arms reaching across distal section of abdominal terminus, (ii) broad elongate neck terminating distally as bilobed knob, (iii) single, elongate, recurved lobe (praegenitale, sensu Tjeder 1966) extending from base of subgenitale, protruding distally from below, then recurving toward base of S7 (Fig. 20). Colleterial gland delicate, with clear membrane, with broad duct leading to colleterial reservoir; colleterial reservoir bulbous, with narrow duct leading to transverse sclerite. Transverse sclerite with comb-like rows of setae.

Specimens examined. USA. AL: Baldwin Co., Bon Secour NWR, 30°15’09”N, 87°48’50”W, 11–15 May 1994, T. L. Schniefer, Mercury vapor and blacklight trap, William H. Cross Expedition (1♂, TRC); Weeks Bay NER Reserve, 30°25’03”N, 87°49’50’W, 4–6 Aug 2000, J. A. MacGowen, blacklight & M.V. lamp in mixed forest near estuary, W. H. Cross Expedition (2♀, TRC). FL: Dixie County, nr. Old Town, 7 Sept 1978, E. R. Hoebeke, M. E. Carter (1♀, TRC); Highlands Co., Archbold Biol. Station, 8 mi. S. Lake Placid, 11 Apr 1974, G. C. Eickwort (1♀, TRC).

Known geographic distribution. Southern USA: AL, AR, FL, GA, MS, TX.