Brachinus pallidus Erwin 1965, NEW SPECIES
Creators: name: Erwin, Terry L.
Publisher: name: Zenodo
Year: 1965
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Brachinus
Brachinus pallidus

description: 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.
description: Published as part of <i>Erwin, Terry L., 1965, A Revision Of Brachinus Of North America: Part I. The California Species (Coleoptera: Carabidae), pp. 1-19 in The Coleopterists Bulletin 19 (1)</i> on pages 8-9, DOI: 10.5281/zenodo.3828883