Atyphella maritimus Saxton & Powell, 2020

Saxton, Natalie A., Powell, Gareth S., Martin, Gavin J. & Bybee, Seth M., 2020, Two new species of coastal Atyphella Olliff (Lampyridae: Luciolinae), Zootaxa 4722 (3), pp. 270-276 : 271-272

Atyphella maritimus Saxton & Powell , sp. nov.

( Figs. 1B, E, H ; 2B )

Type material. Holotype. male ( Fig. 1A ): // Vanuatu: Malekula Is. / Brenwe , -16.1105 / 167.3314, 22.v.2018 / coll. S. Bybee & G. Powell // ( BYU) . Allotype female ( Fig. 2E ): // Vanuatu: Malekula Is. / Brenwe , -16.1105 / 167.3314, 22.v.2018 / coll. S. Bybee & G. Powell // ( BYU) . Paratypes (61 males): (4 ANIC, 3 BYU, 4 NHM, 4 USNM) Vanuatu: Malekula Is. / Brenwe , -16.1105 / 167.3314, 22.v.2018 / coll. S. Bybee & G. Powell // (5 ANIC, 9 BYU, 5 NHM, 5 USNM) Vanuatu: Malekula Is. / Tenmaru , -16.0290 / 167.1728, 24.v.2018 / coll. S. Bybee & G. Powell // (20 BYU) Vanuatu: Santo Is. / Ipayato , -15.6296 / 166.8541, 4.vi.2018 / coll. S. Bybee & G. Powell // (3 BYU) Vanuatu: Santo Is. / Lowerie , -15.1598 / 166.9511 1.vi.2018 / coll. S. Bybee & G. Powell // (4 BYU) Vanuatu: Santo Is. / Lowerie , -15.1598 / 166.9511 5.vi.2018 / coll. S. Bybee & G. Powell //

Other material examined. New Hebrides (= Vanuatu): Malekula Atchin Island , vi. 1929, L. Cheesman, 3 males; Malekula Atchin Island, iii.1930, L. Cheesman, 1 male ( NHM); Malekula, 1 male ( BPBM, per image in Ballantyne and Lambkin 2009) .

Diagnosis. Atyphella maritimus is distinguished from all other South Pacific Atyphella , except A. aphrogeneia and A. marigenous by the thickened elytral apices in conjunction with a dark median marking on the pronotum (see Ballantyne and Lambkin 2009). Atyphella maritimus resembles A. aphrogeneia and A. marigenous but differs in the following ways; excavation on frons shallow (frons deeply excavated in A. marigenous ); pronotum broadly rounded (pronotum with weakly obtuse, anterior angles in A. aphrogeneia ); base of scutellum with dense punctation (punctation larger, but less dense in A. marigenous and A. aphrogeneia ); weak elytral costae (more pronounced elytral costae in A. marigenous ).

Description. Holotype. Male. Overall, body parallel-sided, length 9.8mm, width measured at elytral humeri 3.7mm. Coloration: Elytra and head dark brown to black, pronotum notably lighter, light brown with disc darker ( Fig. 1E, H ). Venter lighter than pronotal margins, becoming darker apically but before the light organ. Sculpturing on dorsal body surfaces moderately shiny beneath pubescence; pubescence fine and gold in color. Legs tan at base, darkening distally. Head: 2.4mm at widest point (center of eyes), eyes large, black; frons depressed, depression broad, widening and becoming shallow towards clypeus, red apunctate region at narrowest point of depression, setae long and golden on frons; antennae filiform, light brown gradually becoming lighter in color distally; scape about 0.3mm long, antennomeres 2–11 broadly uniform in length and about half as long as scape; mandibles sickleshaped, reddish brown, darker toward pointed apices; apical maxillary palpomere enlarged, widest almost at base, apex rounded, longer than wide; apical labial palpomere longer than wide, similar to that of apical maxillary palpomere but smaller and thinner, half as long as apical maxillary palpomere. Pronotum: 2.3mm long, 3.4mm wide, pronotal width slightly less than humeral width; margins light brown, basal third subparallel, broadly rounded anteriorly, weakly explanate, hind angles almost at right angles; disc dark brown, dorsal surface with dense punctation, with dark median region not reaching either anterior or posterior margins, median area of dorsal surface somewhat convex. Scutellum: trapezoidal with dense punctation, dark brown with thin, lighter lateral and posterior margins. Elytra: 7.4mm long, dark brown almost black, parallel-sided; punctures dense, not as large as that on pronotum, unevenly spaced; epipleuron developed as ridge along margin, widest at humeri, narrowing posteriorly, weakly developed towards apex; Costae somewhat pronounced, becoming less defined apically. Abdomen: Ventrites 1–4 tan, becoming darker anteriorly, fat body visible at margins of ventrite 2 to ventrite 4; light organ occupying all of ventrite 5–6. Legs: Dark brown except for pale coxae, trochanters, and basal half of femora; dark marking present on metacoxae. Aedeagus: 1.3mm long, 0.7mm wide, slender ( Fig. 2B ); median lobe slightly longer than lateral lobes; posterior end of lateral lobes curve toward each other; lateral margins of lateral lobes symmetrical, tapering to apex, and rounded, diverging anteriorly; lateral lobes more sclerotized ventrally before apical fourth; median lobe apex rounded and ventrally excavated.

Variation. Males: Length 8.7–10.3mm (n=10), width 2.9–3.3mm (n=10). Pronotum of some specimens lighter in color. Depression on frons sometimes deeper with apunctate region larger. Female: Length, allotype 12.9mm, width 4.7mm. Females similar to males, pubescence more dense on elytra; head is noticeably smaller and covered entirely by pronotum. Eyes much smaller, depression on frons also less developed. Ventral surface overall lighter, without darker patch on metasternite, instead small cloudy darker region on ventrites 1–2. Fat tissue visible through entire ventrites 1–6. Abdomen enlarged.

Distribution. Atyphella maritimus is known from the islands of Malekula and Santo, Vanuatu.

Etymology. In reference to the habitat this taxon is found in, the specific epithet for this species is derived from the Latin term for coastal.

Biology. Atyphella maritimus was collected on volcanic rock outcroppings subject to high tide and frequent waves from the Pacific Ocean. Larvae were observed to inhabit the crevices of these rocks with despite regular sprays of salt-water and individuals were often seen clinging to wet rocks. Adult males were caught flying out over these rocks and climbing on the same rocks as females collected. Only at one locality did we observe a second species of firefly belonging to the genus Maganalata which allowed us to infer the relationship of the males and females here. Additionally, various instars were collected at all locations suggesting that this species reproduces yearround. Nine larvae were collected from Malekula, Tenmaru and completely submerged in salt-water for fourteen hours with a 100 percent survival rate, suggesting that the larvae of this species are at least partially marine and able to withstand being submerged during high tide. The similar biology and morphology of this species to Atyphella aphrogeneia and Atyphella marigneous suggests that these species are closely related.

Figures

FIGURE 1. A–I) Atyphella spp. holotypes. A–C) dorsal pronotum: A) A. aphrogeneia, B) A. maritimus, C) A. marigenous; D–F) scutellum: D) A. aphrogeneia, E) A. maritimus, F) A. marigenous; G–I) left elytron, notice extent of costae G) A. aphrogeneia, H) A. maritimus, I) A. marigenous. Atyphella aphrogeneia holotype images are the property of © CSIRO.

FIGURE 2. A–C) Atyphella spp. dorsal view of aedeagus. A) A. aphrogeneia holotype, B) A. maritimus paratype, C) A. marigenous holotype. Atyphella aphrogeneia holotype images are the property of © CSIRO.