Paleosisyra minor, Wichard, Wilfried, Wedmann, Sonja & Weiterschan, Thomas, 2016

Wichard, Wilfried, Wedmann, Sonja & Weiterschan, Thomas, 2016, Spongillaflies (Neuroptera, Sisyridae) in Baltic amber, Zootaxa 4158 (1), pp. 117-125 : 118-121

Paleosisyra minor n. sp.

Figs. 1–2

Holotype. Male, deposited in the Senckenberg Forschungsinstitut und Naturmuseum, coll-no. SMF Be 2519 (ex coll. Weiterschan no. 1551). The specimen is embedded in a very small piece of amber; it is well preserved, in dorsal view the hindwings are largely covered by the forewings, in ventral view the right fore- and hindwing are distorted and partially covered by thin air films; male genitalia are poorly preserved.

Etymology. The species minor (latin: small) is named after its small size (forewing length 3.5 mm), smaller than P. electrobaltica (forewing length 4–5 mm) and P. eocenica (forewing length 5.2 mm)

Diagnosis. Paleosisyra minor n. sp. comes with the traits of genus Paleosisyra and differs from P. eocenica and P. electrobaltica mainly by the male genitalia. The coxopodits are stocky and almost hemispherical, compared to the elongate and digitiform coxopodits of P. electrobaltica and to the “long” coxopodits of P. eocenica . The forewing venation is characterised by the 3-branched RP in contrast to the 4-branched RP in P. eocenica and P. electrobaltica . Three gradate series of cross-veins can be discerned ( Fig. 1 b). The apical cross-veins are arranged in a more or less aligned outer gradate series. In the forewing of Paleosisyra minor n. sp., CuA runs to the wing margin with only two terminal branches and a final terminal fork. In the hindwing the sinusoid cross-vein rpma-mp originates from MP and enters RP+MA directly at the dichotomous branch ( Fig. 2 b).

Description. Head ( Fig. 1 a): Antenna filamentous, two-thirds of the length of the forewings. Scapus distinctly larger than the other segments; pedicellus smaller, basally narrow and distally globular. The following 29 flagellomeres slightly longer than wide and approximately cylindrical. Maxillary palp 5-segmented, with first, second and fourth segments shorter than the third; terminal segment triangular in dorsal view, twice as long as the third, broadest at base, narrowed and tapered at apex. Labial palps with third terminal segment enlarged, flattened, triangle-shaped, the second segment smaller than the terminal and than the narrow first segments. Dorsal region of the head capsule (vertex) slightly convex, on both sides large compound eyes well visible.

Forewing ( Fig. 1 b): Length 3.5 mm; membrane hyaline; costal area widened, costal cross-veins all simple, about 14 before the apical fusion between Sc and RA; subcostal area between Sc and RA with subcostal cross-vein sc-ra below the 2nd costal cross-vein and above the dichotomous branch of RA and RP+MA, then followed by the dichotomous branch in RP and in MA below the 3rd costal cross-vein.

Between RA and RP cross-vein 2ra-rp just placed basally of the dichotomous branch of RP in RP1+2 and RP3+4. The dichotomous branch of RP1+ 2 in RP1 and RP2 is located close to the next cross-vein 3ra-rp; RP3+4 unbranched, simple; RP 3-branched (RP1, RP2, RP3+4), all 3 branches apically with short terminal forks. MA simple, divided apically into two short terminal branches; MP midway with dichotomous branch MP1+2 and MP3+4, both divided apically into two or three terminal branches. CuA and CuP separated from wing base; CuA running parallel to margin with two terminal branches and finally a terminal fork; CuP simple. Anal veins 1A to 3A all simple, running separately to anal margin.

The area between RA and RP has three cross-veins: 2ra-rp, 3ra-rp and 4ra-rp. Cross-vein 2ra-rp participates in the inner cross-vein gradate series. Crossvein 3ra-rp is connected to the middle cross-vein gradate series. The outer cross-vein gradate series consists of cross-veins running along the furcation of the terminal branches at the apical wing margin, including cross-vein 4ra-rp of the area between RA and RP.

Hindwing ( Fig. 2 a): Costal cross-veins all simple and numerous before the apical fusion of Sc and RA; subcostal area between Sc and RA with a basal cross-vein. At wing base the stem of R hypothetically present and fused with MA; subsequently follows the dichotomous branch with RA and RP+MA; then MA separating from RP. Sinusoid cross-vein rpma-mp originating basally of MP and entering apically RP+MA directly at the dichotomous branch with separated RP and MA ( Fig. 2 b). RP 2-branched, separated in RP1+2 and RP 3+4, all of them with terminal forks. MA and MP simple, with terminal forks. CuA with terminal branches, CuP simple. Anal veins (1A, 2A, 3A) simple, running separately to anal margin. Apical cross-veins forming an outer gradate series.

Male genitalia ( Fig. 2 c, d): The outer genital structures are poorly preserved. The ectoproct is horseshoeshaped but largely covered by a white reflecting air film (verlumt), the gonocoxites (cp) heavily sclerotized, stocky and almost hemispherical; their inner sides slightly concave, apparently with a spacer to keep apart the gonocoxites. Ninth sternite (S9) slightly sclerotized, V-shaped, wide angled, without any posterior processes.

Figures

FIGURE 1. Paleosisyra minor n. sp. (holotype, deposited in the Senckenberg Forschungsinstitut und Naturmuseum, coll-no. SMF Be 2519). a—male in dorsal view; right forewing apically distored, left forewing length 3.5 mm. b—left forewing, scale bar = 1 mm, labelling see material and methods.

FIGURE 2. Paleosisyra minor n. sp. (holotype, deposited in the Senckenberg Forschungsinstitut und Naturmuseum, coll-no. SMF Be 2519). a—male in ventral view. b—hindwing venation. c—male genitalia in ventral view. d—male genitalia in ventrodistal view.