A Revision Of Brachinus Of North America: Part I. The California Species (Coleoptera: Carabidae)
Author
Erwin, Terry L.
San Jose State College, San Jose, California
text
The Coleopterists Bulletin
1965
1965-03-31
19
1
1
19
journal article
http://doi.org/10.5281/zenodo.3828883
2dbd1492-da1f-4175-9353-71d642668466
3828883
CA22A5CE-B3C9-43F2-B5D6-6FA7DACEC956
Brachinus pallidus Erwin
,
NEW SPECIES
TYPE
LOCALITY:
Mad River,
5 miles
east of Mad River Post Office, Trinity County
,
California
.
TYPE
SPECIMENS
: The
holotype
male
and
allotype
female
have been deposited in the entomological museum at the
California Academy of Sciences in San Francisco
. Both were collected by the
author
at the type locality, on
August 16, 1964
. Forty-eight paratypes (of both sexes) were collected by the author at the type locality and from Coyote Creek, 7 miles east of Gilroy, Santa Clara County, California (below Gilroy Hot Springs). Ten of these paratypes are deposited in each of the following: CAS, MCZ, AMNH, and the author's collection. Two paratypes are in each of the following: SJSC, UCD, UIM, and the University of Moscow. The remaining paratypes have been returned to their owners.
DISTRIBUTION: This species is mostly restricted to northern California, with only two populations known to occur south of Monterey Bay (
fig. 13
).
DESCRIPTION: Size. Length 7 to 9 mm.; width 3 to 3:5 mm. Coloration. Elytra
of both sexes dark blue with blue epipleura; head and pronotum ferrugineus; mandibles reddish brown with piceous mesal edges and tip; antennal segments 1-2, legs, and palpi ferrugino-testaceous; antennal segments 3-11 ferrugineus; mesepisterna
and sides of abominal sterna ferrugineus (occasionally caudal half of mesepisterna is brown, in which case sides of abdominal sterna will also be brown). Head. Labrum entire; dorsal surface of mentum slightly convex, with a setae at each anterior corner; bead around eyes entire, thickened at dorsal edge; frons with shallow frontal furrows which are finely rugose; numerous setae arise behind eyes and on top of had; microsculpture consists of very fine isodiametric meshes. Pronotum. Wider just before middle and with sides deeply sinuate; anterior angles slightly prominent; posterior angles acute and directed posteriorly, with lateral basal impressions shallow; lateral margins slightly reflexed, with a narrow bead of slightly darker color than pronotum; disc flat, quite rugose down midline and with a few setiferous punctures on basal half and at anterior corners; microsculpture consists of fine isodiametric meshes. Elytra. Male elytra with sides almost parallel, narrowing very little to slightly prominent humeri; deeply costate; microsculpture consists of fine isodiametric meshes; pubescent bands occur near humeri only in 7th and 8th intervals, but broaden to cover entire elytra beyond apical fourth; a few hairs occur in scutellar region. Female elytra similar, but proportionately wider than those of male in apical half. Aedeagus (
fig. 4
). Phallus prominently compressed resembling a "T" shape in cross section and ending in a feebly rounded point; microsculpture lacking. The endophallus bears a lightly pigmented bilobed virga which is connected ventrally by a thin "bridge."
CALIFORNIA LOCALITY RECORDS: 392 paratypes were examined. Alameda County: (Arroyo Mocho) TLE, (Livermore) CAS, (Sunol) CAS, (Niles Canyon) SDNHM; Amador County: (5 miles west of Sutter Creek on Horse Creek) TLE; Butte County. (Oroville) CAS; Calaveras County: (Mokelumne Hill) CAS; Contra Costa County: (Marsh Creek) TLE; Fresno County: (Camp Greely) CAS; Glenn County: (Elk Creek) CAS; Humbolt County: (Garberville) CAS UIM, (Schively) ATM, (Fort Seward) CAS UIM; Lake County: (Middletown) CAS UIM, (North Fork Cache Creek, Hwy. 20) ATM; Madera County: (Coursegold) CAS UIM; Marin County: (Pt. Reyes) ATM CAS; Mariposa County: (Jolon) CAS, (3 miles S. E. of Jolon) CAS; Napa County: (Rutherford) TLE, (Monticello) ATM; Placer County: (Auburn) ATM; San Joaquin County: (San Joaquin County) SJSC; San Luis Obispo County: (Atascadero) CAS; Santa Clara County: (Gilroy Hot Springs) TLE, (Uvas Creek) TLE, (Isabel Creek) TLE, (Los Gatos) CAS, (Mt. Hamilton) CAS, (San Jose) CAS, (Arroyo Bayo) JGE, (Santa Clara) CAS; Siskiyou County: (south of the Shasta River) CAS; Shasta County: (Anderson) CAS, (Redding) CAS VVB; Sonoma County: (Del Puerto Creek) TLE; Tehama County: (Red Bluff) CAS; Trinity County: (Mad River) TLE; Yolo County: (Putah Canyon) ATM, (Dav'is) ATM.
DERIVATION OF THE NAME: Latin,
pallidus
= pale; referring to the pale ferrugineus venter, limbs, head, and thorax.
DISCUSSION: Members of this species are easily recognized by the compressed ventral surface of the aedeagus, and by the light color of the abdomen and mesepisterna.