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Andrena perarmata Cockerell, 1898
Andrena pyrrhacita Cockerell, 1907; Andrena pyrrhacita var mosina Cockerell, 1908; Andrena pyrrhacita coloradensis Viereck and Cockerell, 1914; Andrena (Andrena) magnifica Viereck, 1924

Life   Insecta   Hymenoptera   Apoidea   Andrenidae   Andrena
Subgenus: Andrena

Andrena perarmata, male, abdomen
Smithsonian Institution, Entomology Department · 9
Andrena perarmata, male, abdomen

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Andrena perarmata, male, genitalia
Smithsonian Institution, Entomology Department · 9
Andrena perarmata, male, genitalia
Andrena perarmata, male, side
Smithsonian Institution, Entomology Department · 9
Andrena perarmata, male, side

Andrena perarmata, male, top
Smithsonian Institution, Entomology Department · 9
Andrena perarmata, male, top
Andrena perarmata, male, wing
Smithsonian Institution, Entomology Department · 9
Andrena perarmata, male, wing

Andrena perarmata, female, face
Smithsonian Institution, Entomology Department · 9
Andrena perarmata, female, face
Andrena perarmata, female, side
Smithsonian Institution, Entomology Department · 9
Andrena perarmata, female, side

Andrena perarmata, female, top
Smithsonian Institution, Entomology Department · 9
Andrena perarmata, female, top
Andrena perarmata, female, wing
Smithsonian Institution, Entomology Department · 9
Andrena perarmata, female, wing

Andrena perarmata, side
Smithsonian Institution, Entomology Department · 1
Andrena perarmata, side
Andrena perarmata, top
Smithsonian Institution, Entomology Department · 1
Andrena perarmata, top

Andrena perarmata, wing
Smithsonian Institution, Entomology Department · 1
Andrena perarmata, wing
Andrena perarmata, face
Smithsonian Institution, Entomology Department · 1
Andrena perarmata, face

Andrena perarmata, side
Smithsonian Institution, Entomology Department · 1
Andrena perarmata, side
Andrena perarmata, top
Smithsonian Institution, Entomology Department · 1
Andrena perarmata, top
Overview
Reprinted with permission of the American Entomological Society from: LaBerge, W. E. 1980. A revision of the bees of the genus Andrena of the Western Hemisphere. Part X. Subgenus Andrena. Transactions of the American Entomological Society 106: 395-526.

Please report text errors to: leah at discoverlife dot org.

Andrena perarmata is a fairly common Salix bee of the western mountains closely related to A. frigida Smith. Both sexes of perarmata are separable from those of frigida by having basal mandibular teeth near the inferior mandibular articulation. The basal mandibular teeth are well developed in the males of perarmata but are small to extremely small and obscure in the females. Both sexes are also marked by having a longer malar space than in frigida, a very broad head and short and closely punctate clypeus. The female is further distinguished by the tergal vestiture being especially long and dense, arising from small but distinct punctures on a tessellate surface. These tergal hairs range in color from almost white through yellow and orange to light fox-red. Lanham (1965) discusses the taxonomic status of Andrena pyrrhacita and correctly associates males from Colorado with females of this species. These males were previously named perarmata, but Lanham did not synonymize pyrrhacita with perarmata. This is done here, after reviewing the type specimens involved.

FEMALE. MEASUREMENTS AND RATIOS. N = 20; length, 11-14 mm; width, 3-4 mm; wing length, M = 5.07 0.183 mm; FL/FW, M = 0.88 0.006; FOVL/ FOVW, M = 2.77 0.053.

INTEGUMENTAL COLOR. Black except as follows: mandible with apical third dark rufescent; flagellum below blackish-brown to dark reddish-brown; tegula piceous; wing membranes hyaline, veins dark reddish-brown to dark brown; tergal apical areas translucent, rufescent; sternal apical areas translucent to hyaline at edges; tarsi dark brown; tibial spurs testaceous.

STRUCTURE. Antennal scape length equals first two and one-third to two and one-half flagellar segments; flagellar segments as in frigida but segment 2 often as long as broad; Eyes each about three and three-fourths times as long as broad, inner margins parallel; Mandibles short, when closed surpassing midlabrum by no more than one-fifth mandibular length; inferior angle or tooth at base present to absent (extremely small when present); Malar space long, minimum length equals about one-third basal mandibular width; Galea as in frigida; Maxillary palpus as in frigida but segmental ratio about as 1.0:0.9:0.8:0.8:0.6:0.5; Labial palpus as in frigida but ratio about as 1.0:0.5:0.4:0.5; Labral process as in frigida but median crista usually distinct; Clypeus sculptured as in frigida but median impunctate line usually present and complete and surface often slightly shinier; Supraclypeal area almost twice as broad as long, rectangular, sculptured as in frigida; Face above antennal fossae and genal area as in frigida; Vertex short, above lateral ocellus equal to half an ocellar diameter or somewhat more (always less than one diameter); Facial fovea shallow, broad, long, extends down to level below lower margins antennal fossae; separated from lateral ocellus by half to three-fourths an ocellar diameter.

Pronotum as in frigida; Mesoscutum, scutellum and mesepisterna sculptured as in frigida; Propodeum as in frigida but dorsal enclosure usually without basal rugulae; Metasomal tergum 1 tessellate, basal area and extending onto apical area with small round punctures separated by one to two puncture widths; Terga 2-4 with basal area punctures more crowded, distinct, separated mostly by half to one puncture width (rarely more), surfaces dulled by fine dense tessellation; Pygidial plate broad at base, V-shaped with distinct raised internal triangle; Sterna sculptured as in frigida.

VESTITURE. Pale specimens with vestiture white to pale ochraceous except as follows: facial fovea with black hairs; face with black hairs on vertex to below ocelli, surrounding foveae and along side compound eye almost to lateral angle of clypeus; propodeum often with long black hairs mixed with pale laterally (in corbiculum); tergum 5 with apical hairs dark brown; tergum 6 with hairs dark brown; hind tibia with posterior half to three-fourths of scopal hairs blackish-brown, apex of femur dark brown, outer surface tarsus dark brown, inner surfaces tibia and basitarsus yellow; fore and middle tibiae and tarsi with outer surfaces dark brown or largely so. Darkest specimens with head hairs entirely blackish-brown; thoracic pleural hairs dark brown; hind tibia with scopal hairs entirely brown; basal segments of legs with dark brown hairs; Intermediate forms may be pale (without red tergal hairs) except having head hairs mostly dark and sterna 2-5 with basal and median hairs dark brown. Darker intermediates have more dark brown hairs plus terga 2-5 with ochraceous to yellow or orange hairs. Hair in general long and abundant; pollen-collecting hairs as in frigida; terga 2-5 with dense, long, erect to suberect hairs partially to completely obscuring surfaces.

MALE. MEASUREMENTS AND RATIOS. N = 20; length, 9-11 mm; width, 1.5-3.0 mm; wing length, M = 4.20 0.380 mm; FL/FW, M = 0.85 0.012; FS1/FS2, M = 1.47 0.028.

INTEGUMENTAL COLOR. Black except as follows: mandible with apical fourth or less rufescent; flagellar segments below dark reddish-brown; tegula piceous to dark reddish-brown; wing membranes hyaline, veins reddish-brown; tergal apical areas translucent, dark rufescent; sterna 2-5 with apical areas hyaline; tarsi dark brown; tibial spurs testaceous.

STRUCTURE. Antennae long, in repose reaching propodeum; scape length and flagellar segments as in frigida but flagellar segment 2 usually longer than broad and almost as long as segment 3; Eyes each about three and one-third times as long as broad, inner margins parallel or diverging slightly towards mandibles; Mandibles decussate as in frigida but inferior margin at base with a distinct sickle-shaped tooth; Malar space long, minimum length equals about one-third basal mandibular width (disregarding basal tooth); Galea as in female; Maxillary palpus as in female but segmental ratio about as 1.0:1.0:0.8:0.8:0.1:0.6; Labial palpus as in female but ratio about as 1.0:0.5:0.5:0.5; Labral process as in female, entire to distinctly bidentate and reflexed; labrum below process without crista, shiny; Clypeus flat, with small round crowded punctures separated mostly by half a puncture width or less, without median impunctate line; surface moderately shiny, faintly shagreened; Supraclypeal area, face above antennal fossae and vertex as in female but vertex usually slightly taller, above later ocellus often equaling one ocellar diameter and (in two males) occasionally more; Genal area as in frigida; Thorax as in frigida but propodeal dorsal enclosure usually without rugulae or roughening basomedially.

Metasomal terga sculptured as in frigida but surface slightly duller, reticularly shagreened, and punctures often more distinct (but not crowded as in females); Sterna sculptured as in frigida; Sternum 6 flat, not emarginate apically or extremely shallowly so.

Terminalia similar to frigida but sternum 7 often minutely emarginate apically, sternum 8 with apical portion broader towards base and gonocoxites with more abundant hairs (Figs; 27-31).

VESTITURE. Generally white to pale ochraceous except as follows: vertex and face alongside compound eyes with long dark brown hairs; genal hairs often black and white mixed especially above; propodeum with dark brown and pale hairs mixed especially laterally, dorsolaterally and posteriorly; terga 3-5 and apical half of tergum 2 with brown hairs or largely brown; Form and distribution of hairs as in frigida.

VARIATION. Lanham (1965) pointed out that females with red tergal vestiture in Colorado tend to occur at 8200 feet in altitude or above, whereas paler females tend to occur at altitudes below 8000 feet. This is upheld in California where females from the higher altitudes in the Sierra Nevada Mountains (and neighboring areas of Nevada) are of the dark type with red tergal hairs, dark head hairs, and dark pleural and sternal hairs, whereas females from the lower altitudes of the Coastal range and from the mountains of southern California are of the palest form. On this basis, Lanham (1965) recognized the dark form as a separate subspecies. Further north, however, in British Columbia, Alberta and Washington, the altitudinal difference is affected by the latitude and one cannot make a distinction so readily. For instance, the Seattle region, at low altitudes, exhibits pale and intermediate types of females. Dark females are known for Agassiz, British Columbia, and Medicine Hat, Alberta, localities of relatively low altitude. It is curious that the males of perarmata show very little variation in vestitural color and the slight variation which exists does not correlate with altitude as in the females. Specimens from southern California (Los Angeles, San Bernardino and Riverside counties) exhibit another variation. The pale females of these localities all have terga 2-4 with hairs relatively short (half as long as hairs of tergum 2 or shorter). The males similarly have short tergal hairs, but only two males from this area have been studied. Also, the females from this area all lack the basal mandibular tooth or angle, whereas the two males examined have these teeth as well-developed as in males from elsewhere in the range of the species. The southern California populations could be recognized as a geographic race on this basis. The few specimens from the San Francisco Bay area in California have the tergal hairs somewhat intermediate in length but more like the normal perarmata females of further north and east. Males of this species exhibit variation in the form of the tip of the eighth sternum which is usually visible in undissected specimens. The eighth sternum may have the tip rounded, truncate or emarginate or bidentate. This led to an attempt to correlate this difference with the dark and pale forms of females with no success. The same collection of males may have either bidentate or entire eighth sternal tips and these types are not correlated with other male characters. Indeed, one specimen was found with one of the teeth evidently broken off and, if both teeth were removed, the result would be a truncate, entire eighth sternum. Perhaps wear is responsible for the variation.

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FamilyScientific name @ source (records)
Apiaceae  Lomatium cous @ BBSL (2)
Polycitoridae  Salix sp @ BBSL (15)
Salicaceae  Salix @ AMNH_BEE (8)

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Updated: 2019-10-19 04:38:20 gmt
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