Sonoma tridens, 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: 22-23

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Sonoma tridens

new species

13. Sonoma tridens   new species

Fig. 13 View Figure 11-16 , 30 View Figure 28-31 ; Map 14

Description. Holotype, male. Measurements: head 0.34 long, 0.42 wide; pronotum 0.46 long, 0.48 wide; elytra 0.76 long, 0.40 wide; antennomeres 1-11 total 1.12; total length 2.38.

Head. Eyes large, maximum length in dorsal view 4/5 length of first antennal segment, with approximately 30 facets. Antennomere 2 approximately 3/4 width of 1; 3 smallest.

Thorax. Elytra with row of approximately 5 fine sutural foveae in basal 2/5; central row of approximately 3 large foveae in basal 1/4. Winged.

Abdomen. Transverse row of microtrichia on first visible tergite narrowly interrupted at midline. No abdominal foveae. Basal pubescence present on all visible ventrites.

Aedeagus. Lanceolate. Left paramere: base broadly oval; apical 1/3 dagger shaped, attached subapically to base, blade not extending to apex of endophallus, extremely acute; setose process bearing 4 thick mesal setae, and 3 lateral thick setae. Endophallus: lateral digitate process very wide, ventrad from right paramere, sharply curved dorsally; apical 1/2 sinuate to right; with small subapical dorsal shelf 1/5 from apex; apex blunt. Right paramere: setose process very large, 4 thick apical setae, dorsolateral seta bifid at tip; lateral constriction at level of digitate process of endophallus very deep; apex acute. Sparse fine tubercles scattered on dorsal surfaces of left and right parameres.

Type Material. Holotype, male: * USA: Ky., Powell Co., Natural Bridge St. Pk., 12–VII–1968, FMHD #68–41, log stump litter, S. Peck ( FMNH) (1M). Deposited in FMNH.  

Geographical Distribution. Sonoma tridens   is known from a single specimen collected in Powell County, Kentucky from within Natural Bridge State Park.

Comments. Sonoma tridens   was collected in July from log and stump litter.

Sonoma tridens   is the only species of Sonoma   in which both parameres and the endophallus have acute apices pointed posteriorly. However if the left paramere of S. mayori   is damaged and possesses an elongate blade-like apex the two species may be distinguished by the presence of the subapical dorsal shelf in the apical 1/5 of the endophallus and the very deep lateral constriction of the right paramere at the level of the digitate process of the endophallus in S. tridens   .

Etymology. The specific epithet of this species refers to the unique trident-like, elongate, posteriorly pointed parameres and endophallus of the aedeagus.


Field Museum of Natural History