Reprinted with permission from: Mitchell, T.B. 1960 Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 141.|
FEMALE—Length 5-7 mm.; black; antennae piceous above, ferruginous beneath; face marks yellow, triangular, filling area between clypeus and eyes, ending acutely on eye margin above antennae; collar and tubercles yellow; tegulae fuscous or blackish; wings subhyaline, veins and stigma fuscous; legs black, but tibiae yellow at base and spurs yellowish; face narrowed below; cheeks narrower than eyes in lateral view; facial foveae deep and distinct, linear, separated from eye by a very slightly wider space and only slightly divergent from eye above; scape slender, no wider than flagellum; very short, about half as long as broad; front coxae simple; dorsal area of propodeum short, about equal to metanotum, coarsely reticulate, metanotum more finely rugose; facial punctures below antennae minute, sparse and obscure, these deep, distinct and closely crowded above antennae; thoracic punctures deep and distinct, moderately coarse, close but not contiguous on scutum and scutellum, more widely separated but not sparse on pleura; abdomen shining, punctures exceedingly minute, but visible with high magnification, well separated on 1st and 2nd segments.
MALE—Length 4.5-7.0 mm.; black; antennae piceous above, ferruginous beneath, scape entirely black; mandibles and labrum black; tegulae brownish-ferruginous or piceous, not maculated; wings subhyaline, veins and stigma brownish-ferruginous; maculations yellow, as follows: entire face below antennae, supraclypea mark reaching to about mid line of antennal fossa, lateral face marks extending in a triangle slightly above antennae, more or less acute, tubercles, a line on each side of collar, a narrow line on anterior face of front tibiae, basal third of mid tibiae, basal half (or slightly less) of hind tibiae, all basitarsi and tibial spurs; apical tarsal segments and front tibiae in large part more reddish; femora black; face narrowed below; cheeks somewhat narrower than eyes in lateral view; scape rather slender, apex slightly broader than flagellum; basal segment of flagellum slightly broader than long, length and breadth of 2nd segment about equal, 3rd much longer than broad; front coxae simple; dorsal area of propodeum about as long as metanotum, coarsely reticulate, metanotum more finely but densely rugose; thoracic punctures deep and distinct, close and rather fine but not crowded on scutum, coarser and well separated on scutellum and pleura; basal segment of abdomen shining, very sparsely and minutely punctate medially, closer laterally, more close, deep and distinct, yet minute on 2nd segment, becoming still closer but more obscure on following segments.
DISTRIBUTION—This occurs throughout the entire Eastern United States and Eastern Canada, from Louisiana to Minnesota, east to the Atlantic seaboard, with the possible exception of Florida. It is in flight from May until September, according to records now at hand.
FLOWER RECORDS—Specimens have been recorded from the following: Acer, Achilea, Angelica, Apocynum, Aralia, Aruncus, Azalea, Castanea pumila, Ceanothus, Chrysanthemum, Crataegus, Cicuta maculata, Daucus carota, Erigeron, Eupatorium, Gerardia, Houstonia purpurea, Hydrangea, hex, Koellia, Pyracanthci, Rhus, Rosa, Rubus, Solidago, Spiraea and Zizia. Robertson (1929) records this species (as P. sayi) on the following additional genera:
Amorpha, Arabis, Cacalia, Cornus, Rubphus, Geum, Heracleum, Lepiclium, Malva, Monarda, Osmorrhiza, Pastinaca, Ptelea, Pycnanthemum, Sanicula, Sium, Symphoricarpus, Taenidia and Thaspium.
From Mitchel (1960) - The females of H. modestus vary considerably in size, ranging from 5 mm to an extreme of 7 mm, and somewhat in extent of maculations, but are otherwise fairly constant. The males, however, are subject to much variation, and as a result, several names have been proposed for these differening forms. In size, they range from 4.5mm to 7mm. The scape varies in size, being quite slender in some individuals, very robust in others, and with all intergrading sizes evident in any extensive series. The pleural punctures also vary in their relative density, being quite close in some, rather sparse in others. The extent of the maculated areas varies most conspicuously. The mandibles and labrum may be entirely black, largely yellow, or with smaller yellow infusions. The lateral face marks may be abruptly truncate at the level of the antennae or may extend upward along the eye margin for some distance, and may be pointed on the eye margin or rounded above and slightly divergent. The collar may be largely yellow, or have only small yellow spots, or even be entirely black, and the tegulae may have large conspicuous yellow maculae, or small obscure spots, or none. The is no constant combination of these variations in any series studies so far that would indicate racial groups, except that there is a tendency for the yellow maculations to be extensive or limited, as the case may be, somewhat uniformly. Thus a specimen with maculated tegulae is likely to have a yellow collar, while one with a black collar usually has dark mandibles and tegulae, but there is no constancy in this, and all intergrades exist.