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 –4 View FIGURES 1 – 4 , 10 View FIGURES 9 – 11 , 15 –17 View FIGURES 12 – 20 , 23 View 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]” ( CNC). PARATYPES: Same data as holotype, 5 ♂ and 2 ♀ each to CNC and 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 ♂, USGS); Thru Sprs, UV light trap, 15– 16.viii. 2006, C. Parker & J. Robinson (3 ♂, 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 ♂, 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. 38 View 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. 3 View 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. 3 View 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 10 View FIGURES 9 – 11 , 15–17 View FIGURES 12 – 20 , 23 View FIGURES 21 – 24 ): 9 S lightly sclerotized, with straight anterior margin. Proctiger heavily sclerotized ( Figs 15 –17 View FIGURES 12 – 20 , 23 View FIGURES 21 – 24 ). Cercus narrow, acuminate, as long as lateral width of proctiger ( Figs 10 View FIGURES 9 – 11 , 15 View FIGURES 12 – 20 ). Basal gonocoxal lobe directed posterodorsally in lateral view with apex distinctly falcate ( Fig. 10 View FIGURES 9 – 11 ), appearing rectangular in ventral ( Fig. 16 View FIGURES 12 – 20 ) and terminal views ( Fig. 17 View FIGURES 12 – 20 ). Apical gonocoxal lobe blunt, directed mediolaterally, in lateral view appearing ca. 1 / 5 X or less of gonostylus length ( Figs 10 View FIGURES 9 – 11 , 15 View FIGURES 12 – 20 ). Gonostylus triangular in lateral view, ca. 1.3–1.5 X longer than greatest depth, ventral margin noticeably convex, bulbous ( Fig. 10 View FIGURES 9 – 11 ).

Female ( Fig. 4 View 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. 37 View FIGURE 37 ).

Remarks. This species is known from streams ranging from small first order hillside trickles ( Fig. 33 View FIGURES 31 – 36 ) to raging torrents ( Fig. 34 View 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