A review of the cleptoparasitic bee genus Townsendiella (Apidae, Nomadinae, Townsendiellini), with the description of a new species from Pinnacles National Park
Author
Orr, Michael C.
Author
Griswold, Terry L.
text
ZooKeys
2015
546
87
104
http://dx.doi.org/10.3897/zookeys.546.6443
journal article
http://dx.doi.org/10.3897/zookeys.546.6443
1313-2970-546-87
1CEAF6086B6A4DBD929DA5FFA2FB776B
1CEAF6086B6A4DBD929DA5FFA2FB776B
Taxon classification Animalia Hymenoptera Apidae
Townsendiella ensifera
sp. n.
Figs 1a, 3a, 4a, 5a, and 6-8
Type-locality.
USA, California: San Benito County, Pinnacles National Park, East of Mount Defiance, 36.46060 -121.15210, Blue oak woodland, white pantrap, 29 May 1999, O. Messinger leg., host unknown.
Holotype.
Female, pinned. Original label: "USA CA San Benito Co., / Pinnacles Natl. Mon., / East of Mount Defiance /
36°28.24'N
121°09.13'W
[white typed label]" "White pantrap, burn / Blue oak woodland [white typed label]" "29 May, 1999 / O. Messinger [white typed label]" "NativeBeeSurvey / USDA,Logan,Utah / BBSL331869 [barcode label]."
Paratypes.
Nine topo-typical specimens (1F8M); all deposited in the NPIC. Unique specimen identifiers are as follows: BBSL330902, BBSL331852, BBSL331878, BBSL331886, BBSL331887, BBSL331891, BBSL332126, BBSL332137, and BBSL332139. Selected specimen data for each paratype is available in the Suppl. material 1.
Other material.
Additional records are detailed in the Suppl. material 1.
Diagnosis.
Both males and females are most similar to
Townsendiella pulchra
and are separated easily from other
Townsendiella
by the absence of a medially projecting knob on the metanotum, the length of the marginal cell being about equal or greater than the distance from its posterior tip to the posterior tip of the wing, and the asymmetrical second submarginal cell with the longer, more curved distal vein. From
Townsendiella pulchra
, it may be differentiated by the following characteristics: five maxillary palpomeres, the final palpomere almost as long as the second palpomere; male pygidial plate narrower, sharper at the tip; female S5 lacking a pubescent apicomedial area, setal density roughly even along rim; when viewing the genital capsule laid flat against a surface, with your view perpendicular to the surface: the tip of the male gonostylus is about its maximum width distant from the gonocoxite tip, while in
Townsendiella pulchra
it is almost equal; male gonocoxite with shorter, fewer, and less plumose setae present ventrolaterally (Fig. 5a) compared to
Townsendiella pulchra
(Fig. 5b); and male genital capsule smaller overall, with gonocoxites less expanded apically (Figs 4, 5).
Figure 3. The female T5 of a
Townsendiella ensifera
sp. n. (BBSL331869) and b
Townsendiella rufiventris
(BBSL209499). The latter has a distinctly impressed, finely-pitted, and tessellate lunule medially in the pseudopygidial area, a feature unique within
Townsendiella
. The scale bar represents 0.5 mm.
Figure 4. The male genitalia of a
Townsendiella ensifera
sp. n. (BBSL259479) and b
Townsendiella pulchra
(BBL340294). Dorsal view of genital capsule and gonostylus. The scale bar represents 0.25 mm.
Figure 5. The male genitalia of a
Townsendiella ensifera
sp. n. (BBSL259415) and b
Townsendiella pulchra
(BBSL349670). Lateral view of gonocoxite, with focus on setae. The scale bar represents 0.25 mm.
Description.
Female: Head: Pubescence dense, white, covering one-half to three-fourths of height of compound eye, becoming sparser, less plumose, and often off-white in coloration dorsally. Facial integument black, reddening, if present, limited to labrum and rim of clypeus. Punctation relatively dense throughout, integument shining between punctures. Mandible simple, basal three-fourths to four-fifths of integument dull orange to bright yellow, tip reddish-brown. Clypeus protuberant from anterior margin of compound eye by one-third to one-half of maximum compound eye width. Integument of antenna dark brown to black, sometimes light brown. Compound eyes slightly converging ventrally. Lateral ocellus distinctly closer to rear margin of head than compound eye, separated from rear margin by roughly 2
-2.5x
lateral ocellar diameter.
Mesosoma: Pubescence all white except for light brown areas of mesoscutum and mesoscutellum. Pubescence dense over mesosoma, except slightly less dense where brown, sparser on pronotum anteriorly, mesepisternum anteriorly, and propodeal triangle below metanotum. Mesoscutum with pubescence primarily light brown except along border, with two thin, longitudinal stripes of white setae intruding posteriorly from anterior margin for one-third to one-half of mesoscutal length. Mesoscutellum
with
pubescence largely light brown, bordered by white, with anterior-directed stripe of white setae from posterior midline. Integument dark brown to black, often with pronotal lobe reddened, less commonly reddened ventrally or elsewhere on pronotum. Punctation dense throughout mesosoma, except propodeal enclosure where absent or obscured by tessellation, integument otherwise relatively smooth and shiny. Tegula brown, slightly transparent, but obscured by dense setae.
Wings: Wings equal to 3.0
-3.1x
medial length of mesoscutum along longitudinal axis. Length of marginal cell slightly greater than distance from distal tip of marginal cell to apical tip of wing. Length of posterior margin of first submarginal cell greater than that of second, but clearly less than twice length of second. 2m-cu usually interstitial with juncture between first and second submarginal cells, or only slightly past this point, creating four-way intersection.
Legs: Integumental color variable, ranging from dark brown to light reddish-brown; tarsi typically black. White pubescence present ventrally on femora, variable in extent. Outer surfaces of tibiae densely clothed in white pubescence, densest on metatibia. Thicker, spine-like setae readily apparent on meso- and metatibiae, usually obscured by pubescence on protibia.
Metasoma: Pubescence white except in basal areas of terga, where it is slightly browned; brown setae obscured on T5 by white setae throughout. Pubescence denser and more branched apically on terga, creating distinct setal bands on T1-T4, each of which is usually thinner medially and thicker laterally, with V-shaped medial notch. Sternal pubescence primarily white but thinner and sparser in basal and lateral areas, appearing apically banded at some angles. S5 pubescence relatively even throughout. Integumental color of terga highly variable, ranging from nearly all black to nearly all red. T5 even across its rim, with simple setae extending posteriorly. Pygidial plate roughly square, only slighter wider at base than apex due to rounded posterior corners; entire rim slightly raised into carina, marked by darker, blackish integument there compared to pitted, redder interior.
Male similar to female, except as follows: Head: Pubescence all white, dense over much of lower face up to slightly below top of compound eye and on gena to about top of compound eyes, becoming less branched and, in some specimens, slightly off-white near vertex. Clypeus protuberant from anterior margin of compound eye by about half of compound eye width or slightly less. Paraocular area raised into flange adjacent to clypeus, this area impunctate and shiny. Integument of antenna dark brown to black, sometimes slightly lighter brown on apical segments.
Mesosoma: Integument dark brown to black, rarely with dark reddish-brown coloration on pronotum or venter.
Wings: Wings equal to 3.1
-3.2x
medial length of mesoscutum along longitudinal axis.
Legs: Integumental color variable, ranging from dark brown to light reddish-brown. Metabasitarsus and metatarsus more obscured by white, plumose setae than on other legs.
Metasoma: Pubescence white except in basal areas of terga, where slightly browned; brown setae intermixed with lighter setae in basal area of T6. Pubescence denser
and
more branched apically on terga, creating distinct setal bands on T1-T4, each of which is usually thinner medially and thicker laterally, typically with those of T5 and T6 thicker, more uniform overall. S6 pubescence notably thinner than preceding sterna, not appearing apically banded. Integumental color of terga variable from dull reddish-brown to near black, more often black. Pygidial plate coming to acute point, sides roughly straight to weakly convex, heavily-sculpted medial region often raised, integumental color darker brownish around rim and reddened interiorly.
Figures 6-8. General appearance of the female
Townsendiella ensifera
sp. n. holotype (BBSL331869). 6 Anterior view of face 7 Dorsal view of body 8 Lateral view of body. All scale bars represent 0.25 mm.
Etymology.
The specific epithet,
ensifera
, is Latin for sword-bearing. This name is primarily a reference to the elongate, sword-shaped terminal maxillary palpomere, and secondarily a reference to its cleptoparasitic life history.
Distribution.
Townsendiella ensifera
is known primarily from the South Coast Range of California, where it has been found at two localities: Pinnacles National Park in San Benito County and San Luis Obispo County, 6 mi NE Santa Margarita. The only other record is a single specimen from south of the Transverse Range ("The Gavilan") near Riverside, California. More collections are necessary to determine the true extent of this
species'
range, although it presently appears more restricted than most other
Townsendiella
.
Phenology.
Known to be active from early May to late August. Within Pinnacles National Park, where multiple collections took place, it was collected from early May to early July.
Bee hosts.
There is no direct knowledge concerning the host of
Townsendiella ensifera
. Given the apparent preference of the similar
Townsendiella pulchra
for species of
Hesperapis
Cockerell and the extensive sampling of Pinnacles National Park,
Hesperapis
as a potential host may be inferred as a working hypothesis. Only two species of
Hesperapis
,
Hesperapis (Amblyapis) ilicifoliae
(Cockerell, 1910) and
Hesperapis (Panurgomia) regularis
(Cresson, 1878), have been recorded from Pinnacles.
Hesperapis regularis
is many times the body size (>12 mm in length) of
Townsendiella ensifera
, while
Hesperapis ilicifoliae
is about 5-6 mm in length, suggesting
Hesperapis ilicifoliae
is the better candidate as host. The likelihood of
Hesperapis ilicifoliae
as host increases when considering that it belongs to the same subgenus as
Hesperapis (Amblyapis) larreae
Cockerell, 1907, the host for
Townsendiella pulchra
(
Rozen and McGinley 1991
). Further support is derived from the synchrony of their flight periods; both
Hesperapis ilicifoliae
and
Townsendiella ensifera
fly from May to July, with the majority of records from June and July. It should also be noted that the specimen of
Townsendiella ensifera
from Gavilan, California was collected on
Adenostoma fasciculatum
Hook. & Arn., the plant which
Hesperapis ilicifoliae
specializes on, and in an area where
Hesperapis ilicifoliae
has been collected previously (
Moldenke and Neff 1974
,
DiscoverLife 2014
). In fact,
Townsendiella ensifera
has only been collected in areas where
Hesperapis ilicifoliae
is known. Based on all evidence,
Hesperapis ilicifoliae
is currently the most likely host for
Townsendiella ensifera
.
Floral hosts.
Polygonaceae
:
Eriogonum fasciculatum
Benth. and
Rosaceae
:
Adenostoma fasciculatum
.
Discussion.
This species is much closer in body form to
Townsendiella pulchra
than the other species are to each other or to the pair of
Townsendiella ensifera
and
Townsendiella pulchra
. It is possible that these very distinct species led to a general expectation of great differentiation between species in the group and that the relatively minor differences between
Townsendiella ensifera
and
Townsendiella pulchra
were overlooked as a result.