Extracted from: LaBerge W.E., (1963). New Species and Records of Little-known Species of Melissodes from North America (Hymenoptera: Anthophoridae). The University of Nebraska State Museum, Volume 4, Number 10, pp. 227-242|
This small species is unique among the Tachymelissodes in that the male first flagellar segment is short, being only one-fourth to one-fifth (minimum length) as long as the second segment. In this respect M. sonorensis is very similar to lVI. monoensis LaBerge of the subgenus Eumelissodes. However, the form of the terminalia, especially of the seventh sternum, and the metasomal fasciae of both sexes places sonorensis among the Tachymelissodes. lVI. sonorensis is most closely allied to M. opuntiella Cockerell from which it can be distinguished readily by the short first flagellar segment and the yellow labrum of the male and by the smaller size and more densely punctate terga of the female.
Female. Measurements and ratios: N, 2; length, 9 mm.; width, 2.5 mm.; wing length, 13.5 mm.; hooks in hamulus, 11; flagellar segment l/segment 2, 1.83.
Structure and color: Integument black except as follows: eyes gray; flagellar segments 2-10 red below; tegulae testaceous, reddish; wing membranes hyaline, only slightly infumate, veins dark brown; tergum I hyaline and yellowish apically; terga 2-4 narrowly hyaline apically; tibial spurs testaceous.
Clypeus with coarse, round, regular punctures separated mostly by halI a puncture width, slightly elongate near apical margin, surface shiny, unshagreened; face below ocelli with small round punctures separated mostly by one puncture width, surface shiny; compound eye in lateral view about twice as wide as gena; maxillary palpal segments in ratio of about 5:5:4:1. Mesoscutum with posteromedian area punctures round, irregular in size, separated mostly by one-halI to one puncture width, surface shiny; scutellum similar but punctures smaller and more crowded; propodeum with dorsal surface medially impunctate and slightly depressed. Metasomal tergum 1 with apical third impunctate, basal area with small to minute punctures separated mostly by one-half to one puncture width, surface dulled by fine transversely reticulate shagreening but moderately shiny; tergum 2 with apical area with minute punctures, interband zone with small round punctures separated mostly by one puncture width or less, surface as in tergum 1; terga 3 and 4 similar to tergum 2; pygidial plate V-shaped with rounded apex.
Hair: Head white, sparse on clypeus and vertex. Mesoscutal hairs sparse, white anteriorly, brown posteromedially; scutellar hairs brown except peripherally white; pleural and propodeal hairs white. Metasomal tergum 1 with long, erect, white hairs on basal fourth, with short, appressed, brown, inconspicuous hairs medially, glabrous apically; tergum 2 with basal tomentum white, distal pale fascia white, interband zone hairs short, appressed to subappressed, brown; terga 3 and 4 similar to 2; terga 5 and 6 dark brown to black except small white lateral tufts; sterna brown except pale laterally. Legs white except inner surfaces hind basitarsi dark reddish brown, inner surfaces fore and middle tarsi and hind distitarsi red.
Male. Measurements and ratios: N, 6; length, 8-9 mm.; width, 2.0-2.5 mm.; wing length, M =2.47 ± 0.037 mm.; hooks in hamulus, M =10.33 ± 0.366; flagellar segment 2/segment 1, M =4.97 ± 0.942.
Structure and color: Integumental color as in female except as follows: clypeus, labrum (except narrow apical margin), and base of mandible pale yellow; terga 2-5 with apical areas hyaline, colorless; distitarsi rufescent. Maxillary palpi and eye width as in female; penultimate flagellar segment less than three times as long as broad, flagellum in repose not reaching prestigma; sculpturing as in female.
Terminalia much as in M. dagosa (LaBerge, 1956a, p. 1193, figs.118-121) except as follows: gonostylus with only 6 or 7, short, pointed spicules near base on dorsolateral surface; sternum 7 with median plate bare, with a distinct neck; sternum 8 with medioventral tubercle acute, extending to or beyond apical margin, with few exceedingly minute hairs along apical margin.