Nomada fervida Smith

Droege, Sam, Rightmyer, Molly G., Sheffield, Cory S. & Brady, Seán G., 2010, New synonymies in the bee genus Nomada from North America (Hymenoptera: Apidae), Zootaxa 2661, pp. 1-32 : 8-11

Nomada fervida Smith

Figures 27, 28 , 33, 34

Nomada fervida Smith 1854: 247 [Holotype: Natural History Museum, London, Ψ; label data: " Type H.T// B.M. Type Hym 17B.580// Nomada fervida Type Sm.// fervida Type Sm.// [ USA] Georgia "].

Nomada wisconsinensis Graenicher 1911: 239 –240 [Lectotype: Milwaukee Public Museum, Ψ; label data: "[ USA] Randall, Wis. [Wisconsin] Burnett Co., Aug. 5-7, '09 [5-7 August 1909]// TYPE [pink label]// 29752// Nomada wisconsinensis Graen Ψ// Lectotype Ψ Nomada wisconsinensis Graenicher des. Droege et al"] new synonymy, new lectotype designation.

Diagnosis. A group of Nomada species in eastern North America possess a distinct posterior pointing spine on the front coxa; of those, N. fervida is the only one whose females have a high number and density of spinelike hairs lining the outer apical margin of the hind tibia ( Fig. 33 ). Unlike the spaced, spine-like hairs of other species that form a single line along the rim, these hairs number over 20 and form a tightly packed group without any spaces, looking a bit like a bundle of tiny pencils with slightly reddish erasers at the top. Also helpful in identifying this species is the yellow integument on the scutellum and the entirely black propodeum and propodeal triangle.

Males of N. fervida also are identified by the combination of the spine on the front coxa and extremely dense, numerous, stout, reddish, spine-like hairs on the hind tibia ( Fig. 34 ). However, following the pattern of most Nomada species, the spine-like hairs on the hind tibia of the males are not as prominent and consequently must be inspected closely.

Molecular results. We obtained DNA barcoding data from six specimens, three males and two females from Florida and one male from Ontario ( Table 1). The sequence divergence among these specimens ranged from 0–0.2% The male from Ontario matches the description of N. wisconsinensis , having more extensive yellow maculations on the metasomal terga. All of the specimens from Florida have maculations throughout the terga that are tinged with orange-brown rather than entirely yellow.

Variation. Specimens of N. fervida vary primarily in the color and pattern of their maculations. The variability can be roughly characterized according to geographic distribution. There appears to be two main areas where the species has been collected, one centered in the Great Lakes region and one centered in Florida and Georgia. In keeping with the general pattern of many bees and wasps from the Deep South, the southern specimens of N. fervida all have burnt orange overtones to the yellow maculations, while in northern specimens those overtones are much less prominent (although still present to varying degrees). On average, southern N. fervida tend to have the least extensive maculations, partially reduced on the head, mesepisternum, and metasomal terga and sterna; however, there is extensive overlap and similar maculation patterns can be found in both populations. When present, the placement of these maculations is identical in specimens of N. fervida from both geographic locations and there appears to be no significant intraspecific variation in the punctation, body size, relative lengths of the flagellar segments, or number of specialized, spine-like hairs on the outer apical margin of the hind tibia of this distinctive species.

Distribution. Nomada fervida is an uncommon sand specialist with two separate populations, one centered on the sand areas of the Great Lakes and the other from the sand areas of Florida and north into Georgia. Database records from a wide variety of specimen records available on the website Discoverlife (www.discoverlife.org) indicate that the species has been collected outside of these main areas, but we have not confirmed any records aside from the ones listed below. Interestingly, all of the southern collection records for N. fervida only appear to come from the interior of Florida and none from equally sandy coastal dune systems (with the only possible exception of a single record from St. Petersburg, Florida). As with all uncommonly collected Nomada , we would not be surprised if more focused collecting efforts result in additional specimens from similar areas of deep sand, for example in the Sandhills of the Carolinas, New Jersey Pine Barrens, or comparable areas on Long Island and Cape Cod. However, it is interesting to note that T.B. Mitchell (1960, 1962) did not collect this species in North Carolina despite having grown up collecting amidst the large deep sand deposits in the Sandhills and regularly visiting the coastal areas of that state. Similarly, we find it strange that this species appears to be absent from the extensive Nebraska Sand Hills region as well as other interior dunes on the western side of the Great Plains.

Material examined. In addition to the female lectotype designated above, we examined the male lectoallotype which had the following label data: "[ USA] Randall, Wis. [Wisconsin] Burnett Co., Aug. 5–7, '09 [5–7 August 1909]// TYPE [pink label]// 29751// Nomada wisconsinensis Graen ɗ// Lectoallotype ɗ Nomada wisconsinensis Graenicher , des. Droege et al." We examined 39 specimens from the following states and provinces: FL, WI, MI, IL, ON, GA, IN (Appendix).

Comments. We synonymize N. wisconsinensis (representing the northern distribution of the species) with N. fervida (representing the southern distribution) based on both morphological and DNA barcoding evidence. An examination of the two female primary types showed that diagnostic characters, especially those of the mandibles, labrum, propodeum, hind tibia, and metasoma, are the same between the two specimens (the N. wisconsinensis lectotype lacks antennae). The two type specimens appear only to differ in the strength and pattern of yellow maculations, with the N. wisconsinensis lectotype a brighter yellow (the N. fervida holotype appears to be faded, possibly due to preservation), and with the N. fervida holotype having more restricted maculations on T3–T5. Nonetheless, the maculation patterns on the metasoma are very similar for both types, and are the same on both the head and mesosoma. The color pattern differences used to justify the recognition of two distinct species by previous authors fall well within known patterns of northern and southern populations and intraspecific patterns found in other Nomada . Additional support for the synonymy of these two species is provided by the nearly identical DNA sequences from specimens conforming to the type specimens that were caught at both extremes of the species’ distribution (i.e., Ontario and Florida, see above).

We encourage researchers to investigate the large sand deposits of central and eastern North America in June and July, a time when these areas are not commonly visited, to look for more specimens of N. fervida . Note that populations in Florida are active as adults from March until November. While the host for this species is unknown, we suspect that Agapostemon splendens (Lepeletier) may be a good candidate as it is similarly restricted to sandy areas. Similar species of Nomada are known to parasitize other Agapostemon species (as well as Nomia and Exomalopsis ).

Figures

FIGURES 27, 28. Nomada fervida, dorsal habitus. Fig. 27. Female. Fig. 28. Male. FIGURES 29, 30. Nomada texana, dorsal habitus. Fig. 29. Female. Fig. 30. Male.

FIGURES 33 – 38. Outer apical surface of hind tibia. Figs. 33, 34. Nomada fervida. Fig. 33. Female. Fig. 34. Male. Figs. 35, 36. Nomada texana. Fig. 35. Female. Fig. 36. Male. Figs. 37, 38. Nomada tiftonensis. Fig. 37. Female. Fig. 38. Male.