Howickia myersi (Richards) Richards, 2014

Marshall, S. A., Luk, S. P. L. & Dong, H., 2014, A revision of the New Zealand species of Howickia Richards, Zootaxa 3887 (1), pp. 1-36 : 24-26

Howickia myersi (Richards) comb. nov.

( Figs. 17, 18 , 53–56 )

Leptocera (Biroina) myersi Richards, 1973: 349 Biroina meyersi, Marshall, 1989: 602

Biroina myersi, Roháček et al., 2001: 125

Description. Colour: Brown to black, head reddish brown to reddish yellow; knees paler; antenna, palpus and tarsi white; halter brown to black on a yellow stem; anepimeron darker. Interfrontal area with a broad, silvery microtrichose triangle tapering from ocelli to anterior margin of frons, apex of triangle flanked by bare V-shaped area. Interfrontal bristles inserted on inner margin of silvery microtrichose interfrontal strips; orbital bristles on silvery microtrichose orbital strips; orbital strips usually much darker than interfrontal strips (indistinctly so on very pale or very dark specimens); orbital and interfrontal strips separated by a very narrow bare strip.

Head: Interfrontal bristles in 3 strong equal pairs. Two orbital bristles, lower smaller, upper slightly shorter than outer vertical bristle and much shorter than inner vertical and ocellar bristles. Orbital and interfrontal setulae well developed. Ocelli well developed. Eye distinctly notched at level of antennae, eye relatively small, 1.5–1.8X genal height. Gena mostly microtrichose, with a small anterodorsal shining area. Vibrissa and anterior genal bristle strong. Face tuberculate between antennae, concave at middle. Pedicel with several long bristles along distal margin and with 2 large inclinate dorsal bristles. Arista with long hairs, hairs as long as first aristomere.

Thorax: Scutum with single postpronotal, notopleural, supraalar, postalar and prescutellar dorsocentral bristles; postalar, dorsocentral and apical scutellar bristles subequal. Acrostichal setulae strong but prescutellar acrostichals not enlarged. Scutellum microtrichose, 3.0X as wide as long; apical scutellar bristles twice as long as basal pair. Anterior dorsal katepisternal bristle minute, posterior dorsal bristle small, reaching half way to wing base. Mid tibia with strong, subequal paired proximal and distal dorsal bristles and an additional small anterior bristle above large distal dorsal bristle; ventrally with only a long apical bristle. Hind tarsus with first 2 tarsomeres strongly swollen, together longer than distal 3 tarsomeres. Wing absent, halter well developed.

Abdomen: Capsule-like, syntergite 1+2 entirely separate from and slightly longer than tergite 3; all tergites and sternites dark, microtrichose and sparsely setulose.

Male abdomen: Sternite 5 subequal in length to sternite 4 laterally but deeply excised posteromedially with a pale concavity leaving the sclerotized part of sternite 5 less than half as long as sternite 4 at middle. Subanal plate broad and complete, each half subquadrate, not strongly differentiated from lower/outer part of cercus. Surstylus U-shaped, broad anteroventral lobe with only small bristles, narrow posteroventral lobe terminating in a very large apical spur; spur of left surstylus conspicuously longer and narrower than spur of right surstylus. Hypandrium broadly but asymmetrically fused with anteroventral corners of epandrium, fused area of right side shorter and twice as wide as fused area on left. Ventral lobe of hypandrium prominent. Posterodorsal apodeme of hypandrium strongly developed, reaching anterior surface of distiphallus near base. Distiphallus narrow, tubular. Postgonite uniformly broad, slightly bent anteriorly beyond middle, apex rounded with a beak-like anterior process. Basiphallus frame-like, projecting beyond distiphallus base for a distance equal to one third of width of distiphallus base.

Female terminalia: Tergite 8 divided into 3 sclerites, dorsal sclerite greatly reduced, bare and pale medially; lateral sclerites large, pale and shining except along posterior quarter. Epiproct small, medially pale, with 2 small setae. Hypoproct divided into anterior and posterior parts: posterior part bare and shining laterally, pale medially, setulose along posterior margin; anterior part entirely bare and shining. Sternite 8 small, but distinct and darkly pigmented, posterior portion transverse, broad, microtrichose and setose; anterior portion narrow and bare. Spermathecae broadly oval, with transverse grooves.

Type material. Holotype: The unique holotype ( BMNH; examined and illustrated by the first author in 1989) is a female from Day's Bridge ("in leaf mould, 12.Jun.1922, J.G. Myers"). Although there is no further locality information on the label, and no current locality is called "Day's Bridge", there is a "Days Bay" in Wellington, North Island. According to Dr. Trevor Crosby (pers. comm.), John Golding Myers was based in Wellington in 1922 and it is therefore "without question that the locality is Days Bay -- at the bridge [ New Zealand, WN]".

Other material examined (Approximately 100 specimens: DEBU, NZAC): North Island: Mt. Ruepehu, Ohakune, 700 m, Rimu Track, 18.Jan.1999, S.A. Marshall; Egmont National Park, Stratford Plateau, 1200 m, pan trap, 8–12.Jan.1999, S.A. Marshall; Mt. Taranaki, Wilkies Pools, 3000 m, moss, 16.Jul.1965, J.I. Townsend; Mt. Pirongia, 800 m, TK2 to Wharauroa, 9.Jul.1977, B.M. May. South Island and nearby small islands: Stephens Island, 14–28.Jan.1933, E.S. Gourlay; Stephen's Island, ex. litter, Feb.1971, G.W. Ramsay; Westland National Park, Franz Josef, 100–250 m, 14–19.Feb.1999, S.A. Marshall; Takaka, Pupu Springs, 60 m, 6.Feb.1999, dung traps, S.A. Marshall; Reefton, 12.Apr.1977, J.A. Wightman; Abel Tasman National Park, 30 km NW Motueka, 19.May.1982, S. Peck; Nelson, Canaan, ex. litter 17.Sep.1964, L.P. Marchant.

Comments. The type specimen was examined and sketched during a visit to BMNH in 1989, providing some details of head pigmentation and chaetotaxy absent from the original description but mostly supporting the interpretation of the species followed here. Richards’ description differs from all known New Zealand Howickia in one important detail. He clearly states that the mid tibia has "no proximal bristles but a pair of preapical dorsals", while all Howickia species known to us have a strong pair of proximal dorsal bristles. The type has a proximal anterodorsal bristle and an apparent socket where a posterodorsal bristle has probably been broken off. The most significant difference between the type and the specimens described above is the anterior orbital bristle, which is equal in size to the posterior orbital in the type but smaller in the specimens here treated as H. myersi .

This species has the widest distribution and the widest range of colour forms of any New Zealand Howickia , and is the only species known from both the North Island and South Island. The genitalia are distinctive (asymmetrical surstyli, uniquely shaped postgonites) and consistent across the entire range, as are the diagnostic details of head pruinosity.

Figures

FIGURES 15 – 18. Howickia myersi group. Howickia tangata Marshall, sp. n.: 15, habitus; 16, head. Howickia myersi (Richards): 17, live individual in situ; 18, habitus.

FIGURES 53 – 56. Howickia myersi (Richards): 53, epandrium, posterior; 54, epandrium, left lateral; 55, male sternite 5; 56, aedeagus and associated structures.