Reprinted from THE UNIVERSITY OF KANSAS SCIENCE BULLETIN
VOL. XLVI PAGES 509-624 JUNE 17, 1966 No. 16
Systematics of the Genus Augochlorella (Hymenoptera, Halictidae) North of Mexico
By Ellen Okdway|
Female: (1) Length 5 to 6 mm; head with 1.47 to 1.79 mm (holotype=1.79 mm), averaging 1.63 m, width equal to, or slightly greater than length. (2) Color yellow-green to dark green (bright green in holo¬type); frons without bluish reflection; metasoma often slightly browner than rest of body. (3) Mandible with basal third dark brown, yellowish brown centrally, rufous at tip, without green basal reflections. (4) Clypeal width equal to or subequal to length (length slightly greater than width in holo¬type), basal two-thirds green, punctures variable, irregularly spaced, smaller basally than apically; apical third brown and slighdy beveled with large, deep, punctures; surface between punctures shiny and smooth. (5) Supra-clypeal area sparsely punctured medially, becoming densely punctured pe¬ripherally; surface smooth to minutely reticulated. (6) Paraocular area with large contiguous punctures below antenna, finely rugose above antenna. (7) Antenna dark brown; flagellum usually lighter below than above; pedi¬cel longer than wide; first flagellar segment slightly wider than long; pedicel longer and narrower than first segment. (8) Scutum smooth, finely and uniformly punctured throughout, punctures small, close, distinct, extending almost to anterior edge; anterior edge with surface slightly roughened medi¬ally as on vertex becoming slightly rougher laterally to very finely rugose at anterolateral angles. (9) Tegula 1.5 to 2.0 times as long as wide. (10) Scu-tellum rough with fine, shallow, irregular to indistinct punctures. (11) Pleu-ron punctorugose to shallowly and finely rugose (finely punctorugose in holotype), areolate anteriorly. (12) Propodeum with disc equal to or slightly longer or shorter than metanotum (slighdy longer in holotype); outline of disc semicircular, profile type 2, posterior edge of disc abrupdy rounded, in¬distinct, more gradually rounded laterally; striae irregular, vermiform or straight (rather straight in holotype), fine and close together, usually ending almost at edge of disc medially, straight and reaching edge but not crossing it laterally; surface at ends of striae minutely roughened, narrowly shiny; posterior vertical surface and posterolateral corners shiny but surface un¬even, without punctures or coarse roughening, often weakly granular posteri¬orly and finely granular at posterolateral corners; lateral surface moderately roughened to weakly rugose (weakly rugose in holotype), without basal subhorizontal rugae. (13) Legs brown, fore and hind coxae with strong green reflections, femora and hind trochanter with weak metallic reflections. (14) Metasomal terga green, suffused with brownish; apical margins nar¬rowly pale brown; first tergum shiny, polished, with numerous, fine, distinct punctures anteriorly, almost impunctate along narrow median longitudinal area, smooth and shiny dorsally with numerous, small, close, distinct, regu¬larly spaced punctures; second tergum with punctures more numerous and smaller; first sternum without metallic reflections. (15) Pubescence golden-white dorsally, white ventrally on head, thorax and basal parts of legs, golden on leg extremities and ventral part of metasoma.
Male: (1) Length 5 to 6 mm; head width 1.53 to 1.76 mm, averaging 1.63 mm, width less than, equal to, or greater than length (width equal to length in allotype). (2) Color yellowish green to dark green; frons without bluish reflections; metasoma variably suffused with brownish. (3) Mandible with¬out metallic reflections basally. (4) Clypeus with punctures large medially small and close basally and laterally; surface between punctures usually smooth and shiny. (5) Supraclypeal area finely punctate laterally; surface shiny basally, usually minutely roughened above. (6) Paraocular area finely and weakly rugosopunctate. (7) Antenna dark brown above, dark yellow below; scape usually narrowly yellow below; last flagellar segment entirely pale brown to dark brown, pedicel and first flagellar segment each less than 1.5 times as wide as long. (8) Scutum shiny and smooth with punctures small, distinct, usually separated by at least the width of a puncture medially, closer laterally and anteromedially; anterior margin weakly roughened as on vertex, becoming weakly rugose at extreme anterolateral angles. (9) Tegula slightly more than 1.5 times as long as wide. (10) Scutellum shiny and punctate; punctures distinct, closer posteriorly than elsewhere. (11) Pleuron rugosely punctate, areolate anteriorly. (12) Propodeum with disc slightly longer than metanotum; outline of disc obtusely V- or U-shaped to semi¬circular (semicircular in allotype), posterior edge sharply angulate to gradu¬ally rounded (abruptly rounded in allotype); striae fine to coarse, regular to irregular (fine and irregular in allotype), reaching edge medially, crossing edge laterally; marginal surface narrowly shiny and slightly roughened pos¬teriorly, shiny posterolateral^; posterior vertical surface either with widely separated shallow punctures and surface between punctures shiny, or weakly roughened and impunctate; posterolateral corners evenly punctate; lateral vertical surface more closely punctate with punctures usually distinct, regu¬lar, separated by about the width of a puncture; surface between punctures finely roughened or entire surface weakly rugosopunctate (punctate in type). (13) Legs light brown; fore and hind coxae, trochanters and femora with metallic reflections; tibiae light brown, yellow-brown at apices; tarsi uni¬formly pale yellow-brown; hind basitarsus with erect hairs of uniform length, about as long as width of basitarsus, basal tuft slightly shorter. (14) Metasomal terga dark green, usually suffused with brownish, yellowish or reddish with apical margins brownish, scarcely contrasting in color with rest of tergum; first tergum polished anteriorly with small, widely spaced punc¬tures throughout; smooth but less shiny dorsally, with punctures variable, usually large, distinct and irregularly spaced; second tergum with punctures of same size but very closely spaced; sterna dark brown, smooth, with short inconspicuous white pubescence; first sternum with weak metallic reflec¬tions; fourth sternum broadly and shallowly emarginate. (15) Pubescence short and white over entire body. (16) Genital capsule, seventh and eighth sterna and eighth tergum of type 1 (Figs. 31, 40, 43).
Comparisons. The females of this species look most like persimilis or the striata-persimilis integrades. The size is small, at most the size of persimilis. The female can be distinguished from the other species found in the United States by its small size, the small but distinctly separated punctures on the scutum, and the lack of coarse roughening or rugosity anteriorly on the scutum (Fig. 78). It is further separated from gratiosa and neglectula by the very smooth posterior surface of the propodeum. Although this is also consistently smoother than aurata, persimilis or striata, the differences among these species in the posterior surface of propodeum are usually too slight to be recognized without comparative material.
The male is about the size and color of the male of persimilis but has the characteristics of a small striata with an emarginate fourth sternum, short basitarsal hair, and with the last segment of the antenna dark. The male genitalia are not perceptibly different from those of other members of the eastern species group, although there is a tendency for the process of the inner lobe of the gonostylus to be shorter and blunter than in other species (Fig. 31). Like the female, the male can be distinguished from all forms of striata by both its small size and its smooth but distinctly punctured scutum.
Variation. The greatest variation in bracteata is found in the characters of the propodeum. Males are in general more variable than females, the females varying chiefly in connection with differences in size. There is little geographical variation, probably due to the limited range and to the few specimens available outside of Texas.
As with most of the eastern species of Augochlorella, there is considerably more size variation in females than in males. This may be due to caste differ¬ences. In females the width of the head is usually greater than the length, but sometimes the width and length are equal. No such general pattern can be established for the males since the length-width ratio is highly variable, even though the overall variation in size is not great.
Color varies from dark green to yellow-green in both males and females, with no apparent correlation between size, date or location. There seems to be an unusual amount of discoloration, fading or bleaching in many of the specimens, especially on the metasoma. Among males, many of the speci¬mens are coppery or reddish (see section on Specific Characters). In spite of the large proportion of specimens thus discolored, freshly caught specimens are probably normally green.
The number and size of punctures on the clypeus of the female is vari¬able. When the punctures are sparse, the clypeus looks smooth, shiny and gently rounded, with the apex also smooth. This condition is apparent especially in the smaller (worker?) individuals. There is little variation in the size and density of punctures in males.
The supraclypeal area in both males and females is usually punctate, with the surface between punctures variably roughened. A female with a sparsely punctate clypeus will usually have a sparsely punctate supraclypeal area, with the central portion smooth and shiny. In the male the supraclypeal area may be shiny with few punctures (14% of the specimens) or with the upper half rough and lower half shiny (67%) or entirely rough (19%).
There is little variation in the punctation of the thorax except as related to the size of the individual bee. On particularly small females the punc¬tures are exceeding small and close and may give the scutum the appearance of being granular rather than punctate.
The rugosity of the mesepisternum also becomes very fine on small fe¬males so that the surface may look similar to that of the metepisternum.
The disc is the most variable structure in this species. Although the edge is rounded in both males and females, it may be smooth and shiny, minutely or weakly roughened, or smooth with minute reticulations. In males the punctures of the posterior vertical surface of the propodeum may reach the dorsal part of the edge on some shiny specimens, and the edge may be more or less sharply defined (but never carinate) with shininess often associated with a rounded edge and dullness with a more distinct edge. A V-shaped depression is rarely apparent but may be indicated on those specimens with a relatively defined edge.
The shape of the disc shows little variation in females. In all cases it is semicircular, like that found in persimilis or in the persimilis-striata inter¬mediates. There, is somewhat more variation in males, with the outline vary¬ing from semicircular to roundly V-shaped, but not bracket-shaped as in striata form A. The striae may be of any thickness from very fine to coarse, especially in males, and may vary from straight to vermiform or, as in some small females, may be so irregular as to be unrecognizable as striae. Striae usually reach ,the edge of the disc, at least medially, where they are usually branched or irregular. In both sexes they are frequently slightly shorter on each side of the median line, where the edge then becomes thicker (see Fig. 66). The striae are straighter and more regular in the larger females than in smaller ones. There is as much variation in the characters of the disc as in persimilis and its intermediates, with some specimens resembling the small striata form c and others resembling persimilis.
The posterior surface of the propodeum is smoother in some females than others but never equals the smoothness of the anterior part of the first ter¬gum. The roughening takes the form of fine granulations or irregularities on an otherwise smooth surface.
The lateral vertical surface of the propodeum ranges from rugose to finely roughened in the females and distinctly and evenly punctured to weak¬ly roughened, largely punctorugose or finely reticulate, in the males.
The metasomal punctures are variable in both sexes, although the type series of 72 females, all collected at the same time and place, are similar in this feature. The punctures on the first tergum in females may be absent in some small specimens or small and irregularly spaced to large, distinct, and closely spaced. There is little indication of regional variation, although most specimens with large, close punctures are from southern Texas. The four specimens from Mexico have small to minute punctures. In males the punc¬tures of the first tergum vary from very small to large, close to widely spaced, with no regional pattern evident. The second tergum of females usually has very small punctures regardless of the size of those of the first tergum. In males both the size and the spacing of punctures on the second tergum are variable, but usually the punctures are smaller than on the first. The third tergum in males sometimes has small but distinct punctures.
There are a few females with all white pubescence over the body. These are usually discolored individuals with brown metasoma (Victoria, Kings-ville, etc.).
Distribution. From northeastern to southern Texas, southward through eastern Mexico to Hidalgo Mexico