Vitaleucopis, Gaimari, 2020

Gaimari, Stephen D., 2020, Two new genera of Nearctic Chamaemyiidae (Diptera: Lauxanioidea) associated with Cinara aphids (Hemiptera: Aphididae) on Pinus, Zootaxa 4852 (1), pp. 61-82 : 67-68

Vitaleucopis gen. nov.

urn:lsid:zoobank.org:act:BB7B83C0-1A53-407C-993D-76429E2EAADB

“Undescribed genus B”— Gaimari 2010: 1005.

Type species. Vitaleucopis nidolkah sp. nov., by present designation.

Etymology. Named for my good friend and premier chamaemyiid expert, the late Vitali Tanasijtshuk, from Vitali truncated and appended to the feminine genus name Leucopis .

Diagnosis. The body is compact and stout, with length 1.9–2.5mm. The head is predominantly dark grey pruinose. Postocellar and ocellar setae are absent. The eye is higher than long, with the height>4 X the genal height. The frons lacks fronto-orbital setae, but has one or two rows of stiff black lateroclinate setulae along the eye margin. In males: the frons protrudes roof-like over the lunule, with a descending lunule and face, and has a cluster of enlarged laterally directed setulae in the anterolateral corners (sometimes clumped into horn-like pencils); and the ocellar triangle is elongate and only slightly tapering anteriorly (never to a point), ending with a dense patch of short white setulae on a distinct pale spot at the anterior tip of the frons. In females: the anterior frons curves into the plane of the lunule, and does not have a cluster of setae in the anterolateral corners; and ocellar triangle tapers to a point ending before the edge of the lunule, and does not have a pale spot or a patch of setulae. The maxillary palpus is spatulate, and in females is enlarged (subequal to first flagellomere) and flattened. On the thorax, the scutum is dark silvery grey pruinose, lacking dorsocentral vittae, setulose dorsally (bounded laterally by supra-alar line), and prescutellar acrostichal setae are absent. The abdomen is shiny black with only sparse pruinosity. In males, microtrichiae are present on the lateral edges of syntergite 1+2 and tergite 3, and the surstylus is long and fully or partly articulating with the epandrium (i.e., is entirely separate, or is partly fused but separated at the base). In females, sternite 6 is wider than the preceding sternites, tergite 7 is entirely membranous, sternite 7 is small with a deeply emarginated posterior margin, tergite 8 is present but lightly sclerotized, and all setulae of the pseudo-ovipositor are large (subequal to setulae of cercus, and only slightly smaller than setulae of the pregenital sternites).

Remarks. In describing Leucopis astonea McAlpine, McAlpine (1977) posited that the species belongs to the group of species including Leucopis argenticollis , Leucopis atrifacies and Leucopis piniperda Malloch. However , despite several characteristics held in common with these species, it is included here in the discrete genus Vitaleucopis, which differs in several substantial respects, including egg and puparial morphology, the male-specific dimorphic characteristics, and the presence of an articulated or partly articulated and elongated surstylus in the male. However, it does seem likely that the new genus belongs to a complex of related genera with similar feeding habits, also including Anchioleucopis Tanasijtshuk , Lipoleucopis de Meijere and Neoleucopis Malloch. Besides the three species described or redescribed here, there is one additional species known, but only from a single female ( Figs 46–47 ), so remains undescribed but is included in the key to species to aid in future recognition. The locality data for this specimen is as follows: USA. CALIFORNIA. Los Angeles Co., La Crescenta, 2 km up Eagle Canyon, on S base Mount Lukens, 30.vi.1994, coll: S.D. Gaimari, ex: Malaise trap (1 ♀, CSCA). This specimen was collected in the same sample with Leucopis atrifacies , and although the author has collected in this area many times over the years, the species has not been encountered again.

Keys to species of Vitaleucopis

The following key separates males and females in the first couplet, because they are sexually dimorphic, and because the female of Vitaleucopis scopulus and the male of the undescribed species are unknown. Given the characteristics typically held in common between males and females, the following observations can be made to aid in recognizing the species for which the opposite sex is not known. For the undescribed species, it is very likely that the male differs from all other species in this genus using the characteristics presented in couplet 4. For Vitaleucopis scopulus , the female will likely key out to Vitaleucopis astonea , given the tarsal coloration in the male; however, no characters are obvious that would set the females of these two species apart.

1. Female (unknown for Vitaleucopis scopulus )............................................................... 4

- Male (unknown for undescribed species)................................................................... 2

2. Anterolateral part of frons with cluster of 2–4 lateroclinate setae, whisker-like (not clustered to appear as 1 very thick seta), with length less than length of inner vertical seta......................................... Vitaleucopis nidolkah sp. nov.

- Anterolateral corner of frons with distinct tight cluster of 4–5 lateroclinate setae (appearing like 1 very thick seta), with length 1.5 X that of inner vertical seta.......................................................................... 3

3. Frons with width and length subequal; distance from vertex to anterior tip of frons 1.7 X width of frons at level of anterior ocellus.......................................................................... Vitaleucopis scopulus sp. nov.

- Frons 1.4 X wider than long; distance from vertex to anterior tip of frons 1.3 X width of frons at level of anterior ocellus.............................................................................. Vitaleucopis astonea (McAlpine)

4. Upper face (between antennal sockets) silvery pruinose; antenna light brown, except basal part orange; palpus orange, with distal part light brown; scutum and scutellum bronzy pruinose, distinctly differentiated from silvery grey pruinose pleuron....................................................................................... undescribed species

- Upper face (between antennal sockets) shiny black, lacking pruinosity; antenna and palpus black; scutum, scutellum and pleuron concolorous silvery grey pruinose..................................................................... 5

5. At least basotarsomere of each leg yellow......................................... Vitaleucopis astonea (McAlpine)

- Tarsi entirely dark brown (hind basotarsomere sometimes dark orange basally)............. Vitaleucopis nidolkah sp. nov.

Figures

FIGURES 46–47. Vitaleucopis (undescribed species from La Crescenta, California), ♀. 46. Head and thorax, anterolateral view. 47. Abdomen, dorsal view.