Sonoma cygnus, Ferro & Carlton, 2010

Ferro, Michael L. & Carlton, Christopher E., 2010, Fifteen new species of Sonoma Casey from the eastern United States and a description of the male of Sonoma tolulae (LeConte) (Coleoptera: Staphylinidae: Pselaphinae), Insecta Mundi 2010 (137), pp. 1-44: 9

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Sonoma cygnus

new species

1. Sonoma cygnus   new species

Fig. 1 View Figure 1-5 , 18 View Figure 17-19 ; Map 5

Description. Holotype, male. Measurements: head 0.33 long, 0.40 wide; pronotum 0.43 long, 0.48 wide; elytra 0.75 long, 0.33 wide; antennomeres 1-11 total 0.96; total length 1.92.

Head. Eyes prominent, maximum length in dorsal view 4/5 length of first antennal segment, with approximately 50 facets. Antennomere 2 approximately 2/5 width of 1; 3 smallest.

Thorax. Elytra with row of three large sutural foveae in basal third; central row of approximately 10 foveae contained in basal 1/2. Winged.

Abdomen. Tergite one with transverse patch of microtrichia narrowly interrupted at midline. Weak basal lateral foveae on ventrites. Basal pubescence present on all visible ventrites.

Aedeagus. Asymmetrical. Left paramere: lobed internally (scoop shaped); short, basal half parallel sided; apical half bulbous, with apical margin mesally and mesal face concave; narrow posteriorly curved hooked process at midpoint of external margin, sub-apical setose process with 7 long stout setae, 3 inserted along lateral margin, 4 at apex of subapical process. Endophallus: base of lateral digitate process 4/ 5 width of base, basally broad, distally narrowed to broad truncate apex, ventrad from right paramere; apical one half thick, strongly re-curved to left. Right paramere: elongate, blade like; dorsolateral lobe on basal third with 6 long stout setae inserted distally; lateral constriction at level of digitate process of endophallus; lateral rounded lobe 1/3 from base; distal 2/3 twisted mesally, apically lamellate and ventral margin curved mesally. Parameres lacking tubercles.

Type Material. Holotype, male: * Rabun Bald , Ga. Rabun Co. 30. V.64 El. 2,500’ / Forest floor debris near dead wood / H. R. Steeves Jr. Collector / H. R. Steeves Jr. Collection / [male symbol] ( FMNH) (1M). Deposited in FMNH.  

Paratypes (n=3). UNITED STATES: NORTH CAROLINA: Macon Co.: *N.C.: Macon Co. 2 mi NW Highlands 19–III–1976 / berlese rhododendron litter LEWatrous ( DENH) (1M). * N.C. Macon Co. Coweeta Hydrologic Lab rhododendron litter 13 Apr. 1979 R. Turnbow ( DENH) (1M)   ; same data (1M) SLIDE   .

Geographical Distribution. Sonoma cygnus   has been collected at three localities, Rabun County in the extreme northeastern corner of Georgia, and two localities in neighboring Macon County, North Carolina. The only available elevational record is from 760 m.

Comments. Sonoma cygnus   adults have been collected during March - May. Specimens were collected from “forest floor debris near dead wood,” and “rhododendron litter” using a Berlese funnel.

Sonoma cygnus   most closely resembles S. baylessae   in aedeagal characters. The hooked process at the external margin of the left paramere, and the narrow digitate process and strongly recurved apex of the endophallus of S. cygnus   will serve to separate it from S. baylessae   . The strongly recurved apex of the endophallus is a unique feature in the genus.

Etymology. The specific epithet refers to the curved apical portion of the endophallus, which is reminiscent of curved neck of some species in the genus Cygnus (swan).


Royal British Columbia Museum - Herbarium


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Field Museum of Natural History


University of New Hampshire