Dixa calciphila , Moulton, John K., 2016

Moulton, John K., 2016, The Dixa inextricata Dyar & Shannon (Diptera: Dixidae) species group, with two new cryptic species from the eastern Nearctic Region, Zootaxa 4121 (4), pp. 458-472: 463-466

publication ID

http://doi.org/10.11646/zootaxa.4121.4.6

publication LSID

lsid:zoobank.org:pub:F15F9CC4-A5CE-45D9-94F7-7C112AE71544

persistent identifier

http://treatment.plazi.org/id/03F37E07-6F4B-410C-FF40-30B5FC97FD18

treatment provided by

Plazi

scientific name

Dixa calciphila
status

sp. nov.

Dixa calciphila  sp. nov.

( Figs 3 –4View FIGURES 1 – 4, 10View FIGURES 9 – 11, 15 –17View FIGURES 12 – 20, 23View FIGURES 21 – 24)

Type material. HOLOTYPE ♂, labeled: “ USA: TN: MARION COUNTY / Spr @ US 64 /TN 41 opposite Raccoon Mtn/ N 35 °03′ 31 ″ W 85 ° 29 ′08″, 243 m / 24.iv. 2014 / J.K. Moulton”; “ HOLOTYPE / Dixa  / calciphila  / J.K. Moulton [red label]” ( CNCAbout CNC). PARATYPES: Same data as holotype, 5 ♂ and 2 ♀ each to CNCAbout CNC and USNMAbout USNM.

Additional material examined. USA: KENTUCKY: EDMONSON COUNTY, Mammoth Cave NP, Cinnamon Fern Bog, UV light trap, 7.vi. 2007, C. Parker & J. Robinson (1 ♂, USGSAbout USGS); Thru Sprs, UV light trap, 15– 16.viii. 2006, C. Parker & J. Robinson (3 ♂, USGSAbout USGS). HART COUNTY, Three Hundred Sprs nr Munfordville, N 37 ° 17 ′ 29.85 ″ W 85 ° 43 ′ 45.70 ″, 29.ix. 2008, JKM— 1 ♂. Unnamed trib Lynn Camp Crk, 10.iv. 2008, JKM— 1 ♂. TAYLOR COUNTY, Little Angel Spr, Trib Craig’s Crk, N of Campbellsville, N 37 ° 26 ′ 40 ″ W 83 ° 21 ′ 18 ″, 9.vi. 2005, JKM; 1.vii. 2004, Malaise trap, G.K. Weddle— 2 ♂. 17.iv. 2005, JKM— 1 ♂, 1 ♀, 1 L; 15.ix. 2005 — 1 ♂. TENNESSEE: FRANKLIN COUNTY, Trib Turkey Crk, ex TN Rt 16 (Old Turnpike Rd.), Walls of Jericho SNA, N 34 ° 59 ′ 40.77 ″ W 86 °03′ 38.98 ″, 23.v. 2008, JKM— 1 ♂. MARION COUNTY, Spr @ US 64 /TN 41 opposite Raccoon Mtn, 243 m, N 35 °03′ 31 ″ W 85 ° 29 ′08″, 24.iv. 2014, JKM— 20 ♂, 7 ♀; 4.ix. 2015 — 5 ♂, 2 ♀. Daniel Cave Spr, N 36 ° 26 ′00″ W 85 ° 48 '00.00″, 8.ix. 2010, JKM— 3 ♂. MORGAN COUNTY, Frozen Head SP, Flat Frk, N 36 °07′ 10.91 ″ W 84 ° 27 ′ 52.67 ″, 20.vi. 2014, JKM— 1 ♂. Obed Wild and Scenic R NP, Melton Mill Br @ Footbridge, Point Tr. below Lilly Bluff Overlook, 357 m, UV light trap, 6.ix. 2005, C. Parker (2 ♂, USGSAbout USGS). PUTNAM COUNTY, Tayes Hollow Spr. @ TN Rt. 84, S of Monterrey, 498 m, N 36 °08′ 12 ″ W 85 ° 17 ′ 28 ″, 17.iv. 2010, JKM— 1 ♂, 2 ♀, 1 L; 7.iii. 2009 — 4 ♂ & 2 ♀; 10.iii. 2009 — 3 ♂, 1 ♀, 6 L; 31.iii. 2013 — 6 ♂, 4 ♀, 4 L, 2 P.

D. calciphila  sp. nov.; 11, D. inextricata  . Scale bar = 50 µm.

Diagnosis. This species can be distinguished from D. appalachiensis  sp. nov. and D. inextricata  by the following characters: Morphological. Ventral margin of gonostylus strongly convex; basal gonocoxal lobe with apex noticeably acuminate; cercus narrow, acuminate, as long as lateral width of proctiger. Molecular. Among the most significant differences within the 66 nucleotides (22 codons) shown ( Fig. 38View FIGURE 38) that serve to distinguish this species from the other two are amino acid substitutions at the following codon positions: 2 (valine/methionine), 3 (alanine/proline), 14 (asparagine/serine), 18 (asparagine/serine), 19 (arginine-CG)/arginine-AG or lycine), and 21 (glycine/absent).

Description. Male ( Fig. 3View FIGURES 1 – 4). Same as D. appalachiensis  sp. nov., except as follows: Wing length (n = 13) 2.6– 3.1 (avg= 2.9) mm. Wing darker smoky gray. Thorax generally darker brown ( Fig. 3View FIGURES 1 – 4), most distinctly differing in katepisternum concolorous with head, anepisternum, and anepimeron and contrasting sharply against whitish to straw-colored mesocoxa. Meron brown, nearly as dark as katepisternum. Terminalia ( Figs 10View FIGURES 9 – 11, 15–17View FIGURES 12 – 20, 23View FIGURES 21 – 24): 9 S lightly sclerotized, with straight anterior margin. Proctiger heavily sclerotized ( Figs 15 –17View FIGURES 12 – 20, 23View FIGURES 21 – 24). Cercus narrow, acuminate, as long as lateral width of proctiger ( Figs 10View FIGURES 9 – 11, 15View FIGURES 12 – 20). Basal gonocoxal lobe directed posterodorsally in lateral view with apex distinctly falcate ( Fig. 10View FIGURES 9 – 11), appearing rectangular in ventral ( Fig. 16View FIGURES 12 – 20) and terminal views ( Fig. 17View FIGURES 12 – 20). Apical gonocoxal lobe blunt, directed mediolaterally, in lateral view appearing ca. 1 / 5 X or less of gonostylus length ( Figs 10View FIGURES 9 – 11, 15View FIGURES 12 – 20). Gonostylus triangular in lateral view, ca. 1.3–1.5 X longer than greatest depth, ventral margin noticeably convex, bulbous ( Fig. 10View FIGURES 9 – 11).

Female ( Fig. 4View FIGURES 1 – 4). Wing length (n = 4) 2.9–3.2 (avg=3.0) mm. Not reliably separated from D. appalachiensis  sp. nov. or D. inextricata  .

Etymology. Named for the karst geography (calc - = lime + - phil = loving) that largely defines the region in which it occurs.

Distribution. Currently known only from Kentucky and Tennessee ( Fig. 37View FIGURE 37).

Remarks. This species is known from streams ranging from small first order hillside trickles ( Fig. 33View FIGURES 31 – 36) to raging torrents ( Fig. 34View FIGURES 31 – 36) originating from underground streams. In central Tennessee adults are already on the wing by early March, earlier than other dixids found in the region. This species has been collected in association with Dixa fusca  , D. modesta sensu Peters  , Dixa  nr. repanda Peters, and a member of the Dixella indiana  complex. This species is expected to occur in northeastern Alabama and possibly, southern Indiana  . Morphologically and molecularly, this species is more distantly related to the other two species in the group than they are to one another.

CNC

Canadian National Collection of Insects, Arachnids, and Nematodes

USNM

Smithsonian Institution, National Museum of Natural History

USGS

U.S. Geological Survey

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Dixidae

Genus

Dixa