Agrotis kuamauna Medeiros & Kirkpatrick, 2019

Kirkpatrick, Jessica, Prestes, Andersonn, Eiben, Jesse & Rubinoff, Daniel, 2019, Two new day-flying species of Agrotis Ochsenheimer (Lepidoptera: Noctuidae) from the alpine summit of the Maunakea Volcano, Zootaxa 4545 (2), pp. 277-285 : 281-283

Agrotis kuamauna Medeiros & Kirkpatrick , sp. nov.

Diagnosis. A. kuamauna is very similar to, and possibly sister to, A. epicremna Meyrick ; both species have acute triangular processes on each segment of the male antennal flagellomere. However, A. epicremna occurs on Haleakalā on Maui and is presumed to eat Argyroxiphium sandwicense ( Zimmerman 1958) in contrast to a diet based on insects, various plants, and lichens, as observed in A. kuamauna ; the spots on the wings of A. kuamauna are consistently more irregular and less well-defined at their edges than those of A. epicremna (see Figs. 1B, 1C, & 1D for comparison).

Description ( Figs. 1B, 1C , & 2B ). Head: Vertex and frontoclypeus mottled black to brown, heavily scaled. Ocelli present. Antenna ca. 0.7–0.8x forewing length; flagellomere bipectinate in males, each segment with acute triangular processes (sensu Zimmerman 1958 pg 216); flagellomere filiform in female. Labial palpus mottled black to brown; porrect; third segment drooping; heavily scaled, length ca. 2.0x diameter of eye; proboscis naked.

Thorax: Mottled black to brown dorsally and ventrally. Legs mottled black to brown with light brown scales near apex of each segment; all tibiae and tarsal segments heavily spined; midleg with one pair of tibial spurs; hindlegs with two pairs. Forewing expanse 31–40 mm (n = 15), ground color brown; pronounced black medial reniform spot present near costal margin; several smaller antimedial black spots present; black subbasal band running from costa nearly to anal margin; irregular black subterminal band present running from costa to anal margin; black terminal spots present; fringe brown; brown ventrally. Hindwing light brown dorsally and ventrally.

Male genitalia ( Fig 3A ): Uncus thin, straight except along base, with fine setae along nearly entire length, heavy at apex. Tegumen truncated at apex. Valva subrectangular, gradually widened on dorsal half, long, narrow, with band of strong setae immediately based of corona. Sacculus well defined, extending ~0.6x length of valva and terminating in a pointed apex, ampulla swollen at base. Saccus narrow, U-shaped, with anterior spine-like projection. Juxta subrectangular. Aedeagus broad, cylindrical, with long internal sac (sensu Zimmerman 1 958 pg 216), apex adorned with very short cornuti.

Female genitalia ( Fig 3B ): Posterior apophysis similar in length to anterior apophysis; ductus bursae 1x as long as anterior apophysis; corpus bursae 0.8x as long as anterior apophysis, signum absent; appendix bursae 9x as long as corpus bursae, apex globose; ductus seminalis originating laterally very near corpus bursae apex.

Abdomen: Brown with tufts of scales projecting laterally from each segment.

Larva ( Fig. 2C ): Early instar larva mottled light brown to dark brown dorsally, four distinct black spots dorsally on each dorsal segment: two anterior spots near each other per segment and two posterior spots farther apart from each other. Black spots not as distinct in mature larva. Faint dorsal-medial line parallel to body, light in color. Semi-transparent ventrally, segments apparent, with sparse setae. Head capsule semicircular, dark brown, mandible strong, antennae with single setae. Each leg with a single terminal claw and long setae.

Pupa ( Fig. 2D ): ~ 15 x 5 mm, reddish brown, rounded anteriorly, tapered posterior. Brownish red, black spots on wings become visible through membrane, blackish brown before eclosion. Darker color lines the posterior of segments 5–10, single cone on segments 6, 7, 8, black spot on segments 5–8. Cremaster small with two acute hooks; hooks diverging from each other.

Holotype: UNITED STATES: HAWAI‘ I: Hawai ‘ i Island: Mauna Kea VLBA, 12,000 ft.: 1 ♂, 8 Jan 2017, J. Kirkpatrick ( UHIM).

Paratypes: UNITED STATES: HAWAII: Hawai ‘ i Island: Maunakea , 3,840m, 19.81544 -155.45583, 26 Oct 2015, pup. 9 & 11 Nov 2015, em. 1 Dec 2015: 3 ♂, J. Eiben ( BPBM) . Maunakea, Halepōhaku region , 3171 m, 19.77039 -155.45267, 21–27 Feb 2014, pup. 1 May 2014: 1 ♂, J. Eiben ( UHIM) . Maunakea, Halepōhaku region , 3171 m, 19.77028 -155.45221, 21–27 Feb 2014, em. 29 May 2014: 1 ♀, J. Eiben ( BPBM) . Maunakea, Halepōhaku region , 9605 ft, N19°45.836 W155°27.668 (at UV light), 28 Jun 2013: 2 ♂ (slide LB84), J. Eiben ( UHIM) . Maunakea, Halepōhaku Facility , 9,270ft 19°45'40.54"N 155°27'20.63"W, 7 Jun 2012: 1 ♂ (slide LB83), J. Eiben ( UHIM) . Maunakea MKSR, 30 Aug 2016: 1 ♀, F. Klasner ( BPBM) . Site ID: TH7, 26 Oct 2015, pup. 15 Nov 2015, em. 4 Dec 2015: 1 ♂, J. Eiben ( UHIM) . Maunakea, Puʻuwēkiu base, 12,750ft 19.81834 -155.4599, 26 Oct 2015, pup. 13 Dec 2015, em. 1 Jan 2016: 1 ♂, J. Eiben ( UHIM) . Maunakea, Puʻuwēkiu base 12,650ft, 19.81815 - 155.45627, 26 Oct 2015, pup. 7 Dec 2015: 1 ♂, Dominique Zarders ( UHIM) . Maunakea, Puʻuwēkiu base, 12,650ft 19.81815 -155.45627, 26 Oct 2015, pup. 12 Nov 2015, em. 1 Jan 2016: 1 ♀, J. Eiben ( UHIM) . Maunakea, North of Puʻulilinoe , 12,700ft, 19.81538 -155.45906, 26 Oct 2015, pup. 29 Nov 2015: 1 ♀, J. Eiben ( UHIM) . Maunakea, West Halepōhaku region , 9,500ft, N19°45.636 W155°27.683 (at UV light), 28 Jun 2013: 1 ♀ (slides LB82 and LB82 “wings”), J. Eiben ( UHIM) . Mauna Kea , TMT13B, 26 Sept 2008: 1 ♀, J. Eiben & Brenner, (voucher AP115; UHIM) . Mauna Kea, PuusVLBA West facing slope, 17 Jul 2006, 1 ♂, D. Rubinoff & J. Eiben, (voucher AP113, UHIM) . Mauna Kea, Burns cone, 14 May 2006: 1 ♂, A. Prestes, (voucher AP114; UHIM) .

Etymology. The Hawaiian word “kuamauna” means “spine [of the] mountain” or “mountaintop,” referring to the presence of A. kuamauna on the uppermost slopes of Maunakea.

Remarks. A. kuamauna larvae have been collected throughout the alpine and subalpine ecosystems (3000– 4205m) on Maunakea including tephra rock cinder cones and glacial till substrates. Larvae appear to be associated with ash substrates which are higher in relative humidity and experience smaller changes in temperature than cinder substrates ( Eiben & Rubinoff 2010). The ash substrates may reduce larval desiccation and allow for thermoregulation in this extremely dry and harsh environment, as has been observed in the co-occurring wēkiu bug ( Duman & Montgomery 1991; Eiben & Rubinoff 2014). Observations made in the lab and field over a decade suggest that the larvae of this species are omnivorous and although they appear to prefer protein sources, they will also feed on plant material blown up to the alpine region ( Howarth 1987); A. kuamauna larvae were observed to readily consume tuna and wind-deposited insects in field baited pitfall traps. A generalist carnivorous diet was observed in the laboratory for this species as well, with larvae able to successfully pupate and emerge as adults after being fed an insect-only diet. Unconfirmed field observations suggest that larvae may also feed on lichens ( Duman & Montgomery 1991). Generally, larvae stop eating and lay in a supine position 2–3 days before pupation. Most larvae pupated on the surface of the ash, but a few specimens also buried their head under the ash with their abdomen erect. One larva built a loose ash case, apparently combined with salivary excretions, in which it pupated. This casing completely covered the pupa and was about 25 mm in length, 15 mm in width, and 10 mm in height. This particular specimen took about 10 days from the time it stopped eating until pupation. Eclosion for all specimens occurred about 30 days after pupation in laboratory temperatures at 20–22°C. Like A. helela , A. kuamauna is diurnal, though not small or particularly dark in color.

Figures

FIGURE 1. A: A. helela, paratype voucher AP117, wing expanse 28.5mm. B: A. kuamauna, holotype voucher AP114, wing expanse 46.6mm. C. A. kuamauna, paratype (voucher AP114; UHIM), wing expanse 40.5mm. D: A. epicremna (voucher AP327; UHIM), wing expanse 48mm. E: A. helela, paratype (voucher AP117; UHIM), wing expanse 24mm. F: A. microreas (BPBM), wing expanse 26mm.

FIGURE 2. A: Wing venation of A. helela (from slide LB81 “wings”). B: Wing venation of A. kuamauna (from slide LB82 “wings”). C: A. kuamauna larva, length = 20mm. D: A. kuamauna pupa, length = 15mm.

FIGURE 3. A: A. kuamauna, male genitalia (slide LB83) scale bars = 1mm. B: A. kuamauna, female genitalia (slide LB82) scale bar = 1mm. C: A. helela, male genitalia (slide LB80) scale bars = 1mm. D: A. helela, female genitalia (slide LB81) scale bar = 1mm.