Extracted from: LaBerge, W. E., 1961. A Revision of the Bees of the Genus Melissodes in North and Central America. Part III (Hymenoptera, Apidae). The University of Kansas Science Bulletin, Vol. 43. 1-107.
The females of this species can be distinguished from females of all other species of the genus Melissodes by the short apical flagellar segments and by the form of the tibial scopal hairs as described below. The males can be distinguished from other males of the subgenus Callimelissodes by the galae being dulled above, he relatively short first flagellar segment and the lack of a longitudinal sulcus on the flagellar segments two through four. In addtion, the males have the labrum and mandibular bases yellow and the apical areas of terga 2 to 4 provided with suberect simple ahirs.
Female. Measurements and ratios: N, 20; length, 9-13 mm; width, 3-4 mm.; wing length, M = 3.23 - 0.673; flagellar segments 1/segment 2, M = 1.73 - 0.087.
Structure and color: Integument black; distitarsi and apical half of mandible rufescent; flagellar segments 3-10 (and often apex of segment 2) red to yellow beneath; eyes usually bluish-gray or gray; wing membranes colorless, veins dark brown; tibial spurs yellow to white.
Clypeus with large, shallow, rounded punctures separated mostly by half a puncture width or less, surface duled by irregular shagreening, without a well-defined boss or median carina apicallyl supraclypeal area with scattered, deep punctures, surface usually dulled by coarse, reticular shagreening; flattened lateral areas of vertex extending medially and somewhat posterior from apices of compound eyes moderately shint, dulled by small, round punctures seperated by one puncture width or less and by delicate, sparse shagreening; apical flagellar segment as broad as long or broader, truncatel eyes in facial view or slightly less than three times as long as wide, converging strongly towards mandibles; maxillary palpal segments in ratio of about 2.4:2.2:2.0:1.0, fourth segment often shorter; galea with scattered punctures bearing short straight hairs, surface opaque, dulled by dense, regular tessellation. Mesoscutum with punctures round, deep, crowded anteriorly and laterally, but sparse in posteromedian area where seperated mostly by two puncture widths and often much more, surface shiny posteromedially but usually dulled anteriorly and laterally by fine shagreening; metanotum with abundant round punctures distinctly smaller than those of mesoscutum, seperated mostly by half a puncture width or less, surface opaque, dulled by delicate, fine tessellation. Metasomal tergum 1 with basal three-fifths with small, round, shallow punctures crowded basally and laterally, sparser apically expect crowded zone at margin of punctate area, apical two-fifths impunctate, surface dulled by dense, reticular shagreening; tergum 2 with basal zone with small, round punctures separated mostly by one puncture width, interband zone with irregular shallow puncture which in lateral raised areas seperated mostly by two puncture widths, apical zone with minute shallow punctures, separated by one to three puncture widths, surface dulled by dense, reticular shagreening; terga 3 and 4 similar, but punctures more crowded in interband zones; pygidal plate V-shaped.
Hair: On head pale ochraceous to white except dark brown on vertex. Thoracic hairs ochraeceous to pale ochraceous expect as follows: mesoscutum with large dark brown posteromedian patch extending forward usually to a transverse line at anterior margins of tegulae; scutellum with large dark brown median area. Metasomal tergum 1 with long pale ochraceous hairs basally and laterally; tergum 2 with basal zone with long pale ochraceous pubescence , with interband zone with short, suberect, relatively simple, brown to dark ochraceous hairs, with broad, arched, distal, pale pubescent band usually interrupted medially and reaching or almost reaching apex of tergum laterally, with apical area with short, simple, appressed to suberect, brown to ochraceous hairs expect narrow glabrous marginl tergum 3 similar to tergum 2 but interband zone often with sparse, appressed, pale pubescence and pale distal pubescent band broader, not interrupted medially and reaching or almost reaching apex of tergum laterally, with apical area with short, simple, appresed to suberect brown to ochraceous hairs expect narrow glabrous margin; tergum 3 similar to tergum 2 but interband zone often with sparse, appressed, pale pubescence and pale distal pubescent band broader, not interrupted medially and extending to apical margin laterally; tergum 4 with broad apical pale ochraceous pubescent band, occasionally with a few simple, pale hairs near margin mediallyl terga 5 and 6 with dark brown hairs except lateral pale ochraceous tufts; sternal hairs reddish brown medially to ochraceous pubescent band, occasionally with a few siple, pale hairs near margin medally; terga 5 and 6 with dark brown hairs except lateral pale ochraceous laterally. Legs with pale ochraceous to white hairs except as follows: distitarsi usually, basitarsi and inner surfaces of fore tubuae brown, inner surfaces of middle and hind basitarsi dark red to dark brown (usually paler on middle basitarsus), on basitibial plates brown: scopal hairs white to ochraceuous, rachises not extending much beyond plumose part, each hair usually with 4 to 6 branches on each side inap ical half or less, with two to several scopal hairs on posterior part of apex of tibia almost sinuous, bent to shape of surface of apical, hairless area of tibia.
Male. Measurements and ratios: N, 20; length, 7.5-11.0 mm.; width, 2,5-4.0 mm.; wing length, M =3.12 - 0.206 mm>; hooks in hamulus, M = 10.95 - 0.526; flagellar segment 2/segment 1, M = 7.14 - 0.189.
Structure and color: Integument black except as follows: clypeus, base mandible and labrum yellow (labrum without dark margin); flagellum yellow to red below (labrum without dark margin); flagellum yellow to red below(except first segment), dark brown above; eyes gray to bluish gray, rarely greenish blue; wing membranes hyaline, veins brown to black, metasomal terga 2-5 usually opqaue, brown, occasiaonlly translucent and yellowish apically; distitarsi rufescent; tibial spurs yellow to white.
Eyes strongly converging towards mandibles, about three-eighths as wide as long; minimum length of first flagellar segment less than one-fifth maximum length of second segment; flagellar segments 5 to 9 with elongate, shiny, shallow, dorsolateral depresions (occasionaly also on segment 10 but never on segment 11), penultimate segment more than twice as long as wide, last segment more than three times as long as broad. Maxillary palpal segments in ratio of about 3.25:3.75:2.75:1.0. Apical margin of sternum 4 tiwh broad flap shallowly emarginate medially; sterna 3 and 5 distincily convex apically. Sculpturing as in female with the following differences: clypeus with puncutres coarse and irregular, with surfaces moderately shiny, slightly dulled by sparse coarse shagreening; supraclypeal area with surface usualy dulled by sense tesselation; galae above with coarse shagreening; tergum 1 with basal four-fifths punctate; terga 2-4 with apical areas often with minute punctures (at least a few present near distal pubescent bands).
Sternum7 with median plate slightly turned laterad, with long, slender neck with apicolateral angle narrow (almost strap-shaped). Sternum 8 with apicoventral tubercle bidentate apically, with few or no hairs at apex. Gonostylus two-thirds as long as gonocoxite, distinctly capitate, with a few slender hairs on outer and lower surfaces near basel spatha sinuate apically about three times as wide as long; penis valve with dorsolateral lamella ending at spatha without being turned inward to form a tooth just in front of spatha.
Hair: On head and thorax pale ochraceous to ochraceous, often with brown on vertex of head and usually with a few long brown hairs poseteromedially on mesoscutum and almost always on scutellum. Metasomal tergum 1 with basal four-fifths with long pale ochraceous hairs, apically with short, suberect, simple, usually ochraceous, but often pale brown hairs almost to apex; tergum 2 with hairs white o pale ochraceous, basal pubescent band white, distal pubescent band white and often borwn at least medially; tergum 5 as in tergum 4 but distal pubescent band usually reaching margin across entire tergum; terga 6 and 7 ochraceous to pale brown; sternal hairs pale ochraceou, often darkened medially; legs with white to pale ochraceous hairs except as followsL pale rufescent to yellow on innter surfaces of basitarsi and often distitarsi.
Distribution. From Alberta, Canada, in the NE to Colorado in the SE, west to southern California and NW to the State of Washington. This species has been collected from May 4 until November 8, but mainly from the middle of June until the middle of September. In addition to the type material, 1080 females and 1337 males have been examined from the localities listed below.