Descriptions of Mature Larvae of the Bee Tribe Emphorini and Its Subtribes (Hymenoptera,Apidae,Apinae)

Abstract

A description of the mature larvae of the bee tribe Emphorini based on representatives of six genera is presented herein. The two included subtribes, Ancyloscelidina and Emphorina, are also characterized and distinguished from one another primarily by their mandibular anatomy. The anatomy of abdominal segments 9 and 10 is investigated and appears to have distinctive features that distinguish the larvae of the tribe from those of related apine tribes.

Full text

Descriptions of Mature Larvae of the Bee Tribe Emphorini and Its Subtribes... 279
Descriptions of Mature Larvae of the Bee Tribe
Emphorini and Its Subtribes
(Hymenoptera, Apidae, Apinae)
Jerome G. Rozen, Jr.
Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th St., New
York, NY 10024, USA
Corresponding author: Jerome G. Rozen, Jr. (rozen@amnh.org)
Academic editor: Michael Engel|Received 22 July 2011|Accepted 2 September 2011|Published 21 November 2011
Citation: Jerome G. Rozen, Jr. (2011) Descriptions of Mature Larvae of the Bee Tribe Emphorini and Its Subtribes
(Hymenoptera, Apidae, Apinae). In: Engel MS (Ed) Contributions Celebrating Kumar Krishna. ZooKeys 148: 279–291.
doi: 10.3897/zookeys.148.1839
Abstract
A description of the mature larvae of the bee tribe Emphorini based on representatives of six genera is
presented herein. e two included subtribes, Ancyloscelidina and Emphorina, are also characterized and
distinguished from one another primarily by their mandibular anatomy. e anatomy of abdominal seg-
ments 9 and 10 is investigated and appears to have distinctive features that distinguish the larvae of the
tribe from those of related apine tribes.
Keywords
Emphorini, Emphorina, Ancyloscelidina, larva, last larval instar
Introduction
A recent study of the immature stages of the Exomalopsini (Rozen in press) presented
a preliminary tribal key based on last larval instars to the non-cleptoparasitic apine
taxa whose larvae were available, exclusive of the corbiculate tribes. It revealed that
the last stage larva of Ancyloscelis apiformis (Fabricius) was in certain ways remarkably
dierent from those of other Emphorini. To investigate these dierences the present
paper describes the tribe based on its mature larvae and then oers a larval descrip-
tion of Ancyloscelis (based primarily on A. apiformis), the only genus in the subtribe
Ancyloscelidina, and compares it with a characterization of mature larvae of the sub-
ZooKeys 148: 279–291 (2011)
doi: 10.3897/zookeys.138.1839
www.zookeys.org
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Jerome G. Rozen, Jr. / ZooKeys 148: 279–291 (2011)
280
tribe Emphorina as listed in Table 1. Although Roig-Alsina and Michener (1993) rst
proposed the subtribe Ancyloscelina for Ancyloscelis, the tribal name was corrected as
Ancyloscelidina and validated by Engel and Michener in Engel (2005). ese are the
only two subtribes of the Emphorini (Michener 2007).
With great pleasure I dedicate this study to Drs. Kumar and Valerie Krishna, long-
term associates and currently next-door oce neighbors, whom I have known for near-
ly a half century. May their good humor and scholarship prevail long into the future!
Aspects of the biology of Ancyloscelis apiformis were described by Torchio (1974),
Michener (1974), and Rozen (1984), and more recently Gonzalez et al. (2007) treated
the biology of Ancyloscelis a. apiformis. Previous descriptions of immature stages were
listed by McGinley (1989).
In the study of larval Exomalopsini, the highly sclerotized mandibular morphol-
ogy revealed considerable structural variation; this variation was not reected in the
surrounding mouthparts, presumably because of their soft, non-sclerotized anatomy.
A preliminary survey of emphorine larval mandibles from the earlier study revealed
mandibular variation as remarkable as that of the Exomalopsini, thus prompting the
current study.
Methods and terminology
For clearing, larvae were boiled in an aqueous solution of sodium hydroxide, stained
with Chlorazol Black E, and then submerged in glycerin on well slides for study and
storage. Specimens to be examined with a Hitachi S-4700 scanning electron micro-
scope (SEM) were critical-point dried and then coated with gold/palladium. Micropho-
tographs of Figs. 1–3 were taken with a Microptics-USA photographic system equipped
with an Innity Photo-Optic K-2 lens system. Microphotographs of mandibles were
taken with a Cannon PowerShot SD880 IS handheld to the ocular of a Zeiss compound
microscope. Fig. 12 was rendered with a Carl Zeiss LSM 710 confocal microscope.
Table 1 gives the full name and authorship of all species treated herein.
For descriptions of mandibles, the right mandible is used and assumed to have its
long axis horizontal making the upper surface dorsal, lower surface ventral, and inner
surface the adoral surface. As explained in Rozen (in press), the cusp is dened as an
adoral extension of the apical mandibular edge that forms the upper boundary of the
apical concavity. It seems well represented in the Emphorina but greatly modied in
Ancyloscelidina because of the blade-like thinness of the mandibular apex and the
coarse serrations of the dorsal apical edge (Figs. 12, 21, 22). e ventrally projecting
tubercle-like structure and surrounding uneven surface (Figs. 12, 21) near the basal
boundary of the apical concavity is likely a derived modication of the cusp.
To determine the foramen-to-head-width index of mature larvae, the maximum
transverse width of the foramen was divided by the maximum transverse head width.
is is a measure of the degree of constriction of the posterior edge of the head capsule
relative to the lateral expansion of the parietals.

Descriptions of Mature Larvae of the Bee Tribe Emphorini and Its Subtribes... 281
Anatomy of Abdominal Apex
is section explores the anatomy of abdominal segments 9 and 10 of the emphorine
last larval instar because certain features found there have been overlooked. Although
this study is based primarily on the predefecating larva of Melitoma grisella (Cockerell
and Porter) and Diadasia rinconis Cockerell, these features are evident on all empho-
rine larvae examined. Abdominal segments 9 and 10 each has a scarcely visible dorsal
sclerotized area that is nearly unpigmented. However, when a specimen is cleared and
stained with Chlorazol Black E, the sclerite of abdominal segment 9 is visible (al-
though poorly delineated) as a narrow, transverse, somewhat impressed (compare with
surrounding integument) dark band (Figs. 1, 2) tapering at both ends and stretching
across the segment somewhat more than halfway to the segment’s posterior edge. Al-
though its anterior margin in gently curved, its posterior margin is broadly V-shaped
and points toward the following segment.
e stained transverse sclerite (also not sharply delineated) of abdominal seg-
ment 10 rings much of the segment but fades ventrally. Its anterior margin ap-
proaches the preceding segment at mid line, so that the sclerites of abdominal seg-
ments 9 and 10 point toward one another suggesting that they function together.
e dorsal part of the posterior edge of the sclerite on segment 10 bends outward
forming a shallow groove in front of it. e abdominal apex lies beyond this sclerite,
and the anus (Figs. 1, 11, 16, 17) is a transverse slit, positioned a short distance pos-
terior to the sclerite. e surface of the abdominal apex between anus and sclerite
projects beyond the sclerite as the raised, verrucose supra-anal surface (Figs. 11, 16,
17) with its dorsal edge forming a semicircle from one side of the anus to the other
when viewed from behind (Figs. 11, 16, 17). is edge often becomes carinate on
postdefecating specimens creating a ridge circling the anus from above (Figs. 11,
Table 1. Taxa of the Emphorini whose mature larvae were examined for current study, with source of
material and other information
EMPHORINI
Ancyloscelidina:
Ancyloscelis apiformis (Fabricius)
Emphorina:
Diadasia (Diadasia) enavata (Cresson)
D. (Dasiapis) olivacea (Cresson)
D. (Coquillettapis) rinconis Cockerell
D. (Coquillettapis) vallicola Timberlake
Diadasina (Diadasina) sp.
Melitoma grisella (Cockerell & Porter)
M. marginella (Cresson)
M. segmentaria (Fabricius)
Ptilothrix bombiformis (Cresson)
P. near sumichrasti (Cresson)
P. tricolor (Friese)
Toromelissa nemaglossa (Toro & Ruz)
KU and AMNH collections
Michener, 1953; AMNH collection
AMNH collection
“
“
“
“
“
“
Michener, 1953; AMNH collection
AMNH collection
“
“

Jerome G. Rozen, Jr. / ZooKeys 148: 279–291 (2011)
282
Figures 1–3. Microphotographs of terminal abdominal segments of cleared, stained emphorine larvae. 1,
2 Melitoma grisella, predefecating, dorsal and lateral views 3 Diadasia rinconis, postdefecating, lateral view.
16). e area below the anus is planar, dened as a semicircle by the conspicuous
setae at the border in the case of Melitoma grisella (Figs. 1, 2, 17); in other species
that area is less well-dened. Hence, the dorsal view of the abdominal apex is an
oval, traversed by the anus (Fig. 1).
e dorsal sclerites of abdominal segments 9 and 10 and the position of the anus
with projecting, verrucose surface, all ringed by ne setae, suggest that these structures
function together for some purpose currently not understood. One can speculate that
these modications support fecal deposition or perhaps deposition of some substance
on the cell wall to safeguard the bee from water loss or parasites. Instead, these features
might relate in some way to locomotion, for how does such an elongate larva move
around in the cell while it feeds and defecates? Careful observations of living specimens
during this stadium will likely lead to an explanation.

Descriptions of Mature Larvae of the Bee Tribe Emphorini and Its Subtribes... 283
Mature larva of Emphorini
Diagnosis: e best way to distinguish larval emphorines from those of other apid tribes
is with the characters indicated in the preliminary tribal key based on last larval instars
to the non-cleptoparasitic apine taxa (Rozen, in press). e presence of ne to moderate
setae on abdominal segment 10 is a feature restricted to the Emphorini and to the exom-
alopsine genus Eremapis among the Apidae, but Eremapis lacks the sclerites of abdominal
segments 9 and 10. Unlike other emphorines, Toromelissa nemaglossa (Toro and Ruz),
known from Chile, has only a pair of setae on the outer surface of its mandible, although
like other emphorine taxa it does possess numerous scattered ne setiform sensilla on
abdominal segment 10 as well as a spiculate mandibular corium. No other bee larva is
known to possess this combination of characters. e following is based on mature lar-
vae of species listed in Table 1, which also indicates the sources of preserved specimens.
Head (Figs. 5, 8, 9, 13): Integument of head capsule with scattered, small sensilla,
many of which are clearly setiform; epipharyngeal surface spiculate but with dierent
patterns of distribution; mandibular corium nonspiculate, except clearly spiculate in
Toromelissa and in some Diadasia. Integument pigmentation variable; mandible pig-
mented apically but far less so basally, with pigmented area usually dened by sharp
line of separation (Figs. 24, 26, 28, 30, 32, 34); hypopharyngeal groove distinct.
Head (Figs. 6, 7) moderately to very small relative to elongate body (Figs. 6, 7);
width of foramen magnum compared to head width as follows: Ancyloscelis 0.73; Dia-
dasia 0.66–0.70; Diadasina 0.67; Melitoma 0.65–0.72; Ptilothrix 0.71; Toromelissa 0.71;
bridge between posterior tentorial pits well developed; rest of tentorium normally robust
for cocoon-spinning larva (even though not all spin cocoons). Center of anterior tento-
rial pit much closer to anterior mandibular articulation than to outer ring of antenna in
frontal view (Figs. 9, 13; ATP = anterior tentorial pit), so that lateral segment (between
anterior tentorial pit and anterior mandibular articulation) of epistomal ridge extreme-
ly short; posterior tentorial pit (i.e., junction point of postoccipital ridge, hypostomal
ridge, and tentorial bridge) in normal position, deeply recessed; all internal head ridges
strongly developed; coronal ridge extending to, or nearly to, middle of epistomal ridge
in frontal view; median section of epistomal ridge more or less well developed; dorsome-
dial portion of postoccipital ridge nearly straight (not bending forward) as viewed from
above; hypostomal ridge without distinct dorsal ramus. Parietal bands faintly evident
as integumental scars. Antennal prominence non-extant; antennal papilla moderate to
large in size, always longer than basal diameter, conical in shape, apically bearing 6 or
more (in some cases many more) sensilla. Apex of labrum at most shallowly emarginated
in frontal view (Figs. 9, 13); apical front surface of labrum with pair of low, forward-
projecting, sensilla-bearing lobes (Figs. 5, 8, 9, 13); transverse labral sclerite absent.
Mandible with two apical teeth but on postdefecating forms mandible sometimes
appearing to have single tooth because of wear; outer surface of mandible with 8 or
more small to large setae at mid length, except Toromelissa with only a pair of setae; other
mandibular features varying considerably between subtribes: see subtribal descriptions,

Jerome G. Rozen, Jr. / ZooKeys 148: 279–291 (2011)
284
below. Labiomaxillary region moderately weakly projecting in lateral view (Figs. 5, 8)
for cocoon spinning larva. Maxilla with apex bent adorally, bearing palpus subapically;
galea not evident; cardo and stipes sclerotized but in some cases unpigmented; articulat-
ing arm of stipital sclerite evident; maxillary palpus well developed, about twice as long
as labial palpus but shorter and more slender than antennal papilla. Labium clearly di-
vided into prementum and postmentum; prementum moderately small in frontal view;
premental sclerite weakly evident; labial palpus about as long as basal diameter. Salivary
opening on apex of prementum, transverse with strongly (Diadasina, Melitoma, Ptilo-
thrix) to weakly (Ancyloscelis, Toromelissa) projecting lips that vary in width; lips consist-
ing of tapering elongate laments (Fig. 15). Except in Ancyloscelis, hypopharynx abrupt-
ly elevated behind articulating arms of stipes, high, sometimes densely covered with
coarse spicules, other times with fewer, ner spicules; hypopharyngeal groove present.
Body: Integument without general body setae, but abdominal segment 10 with ne
to moderately conspicuous setae found especially around anus (a few setae may also be
found dorsally on posterior part of segment 9); ventral surfaces of all segments with
most species spiculate except for segment 10. Body form of predefecating larva (Fig.
6) unusually elongate, linear, parallel-sided; extent of expression of inter- and intraseg-
mental lines variable on predefecating larva (partly determined by amount of food
ingested), on postdefecating larva often evident; dorsal body tubercles usually absent
but see Remarks, below; dorsal tubercles absent on abdominal segment 9; abdominal
segment 9 on pre- and postdefecating forms produced ventrally as seen in lateral view
(Figs 4, 6, 7); abdominal segment 10 positioned dorsally on 9 in lateral view (Figs. 4, 6,
7); anus positioned close to dorsal surface on segment 10 (Figs. 2, 3); on postdefecat-
ing larvae, dorsal surface of segment 10 traversed by groove extending from one side
of anus to other side, its posterior edge ending as strong transverse ridge above anus.
Spiracles (Figs. 4, 6, 7) small to moderate sized, usually inconspicuous, subequal in size
throughout, not surrounded by well dened sclerites, and not on tubercles; peritreme
present; atrium projecting beyond body wall, with distinct rim, globose; atrial wall
smooth, without ridges or spines, moderately thick; primary tracheal opening with
collar; subatrium consisting of about 12 chambers; subatrial chambers decreasing in
outside diameter from body surface inward. Males to extent known (but unknown in
case of Ancyloscelis apiformis) with single median scar on apex of ventral protuberance
of abdominal segment 9; females presumably lacking scars.
Remarks: Although dorsal body tubercles are generally absent on mature larvae,
earlier instars and even on early stages of last larval instars have paired tubercles on most
body segments rising from the middle of each segment for abdominal segments 9 and
10. (ese tubercles should not to be confused with the middorsal tubercles of immature
Megachilidae, which are intersegmental in position, Rozen and Hall (2011) gs. 85, 86.)
Each tubercle is small but often rises sharply with its front-to-back measurement
about the same as the lateral measurement (i.e., tubercle non-transverse). Tubercles
are uniquely positioned for bee larvae: those of each segment tend to be contiguous,
lying close to the body midline. On some species they appear to be a single median
bimodal tubercle.

Descriptions of Mature Larvae of the Bee Tribe Emphorini and Its Subtribes... 285
Figures 4-8. 4–5. Diagrams of mature larva of Ancyloscelis apiformis, lateral view 4 Posterior part of ab-
domen of predefecating form 5 Head. 6–8. Diagrams of last larval instar of Diadasia rinconis, lateral view
6 Predefecating form 7 Postdefecating form 8 Head, lateral view; Figs. 6 and 7 to same scale.
Figures 9-12. 9–11. SEM micrographs of last larval instar of Ancyloscelis apiformis. 9 Head, frontal view
10 Antenna with many sensilla 11 Abdominal segment 10, posterior view. 12. Confocal micrograph of
mandible of same, ventral view.

Jerome G. Rozen, Jr. / ZooKeys 148: 279–291 (2011)
286
Mature Larva of Subtribe Ancyloscelidina
Description: Head (Figs. 5, 9): Epipharyngeal surface with patch of short but abundant
spicules covering most of anterior surface on each side; mandibular corium nonspicu-
late. Integument unpigmented except for mandibular apices and mandibular points of
articulation with head capsule; hypopharyngeal groove faintly pigmented.
Mandibular apex uniformly pale tan, with sharp line demarking tan apex from
nearly pigmentless basal part of mandible as seen in dorsal view (Fig. 22, though val-
ue contrast generally not as great as in mandible of Emphorina). Entire mandibular
apex rotated and attened, blade-like, so that coarsely serrated dorsal edge directed
adorally, forming very broad, ventrally directed apical concavity (Fig. 12); dorsal api-
cal tooth elongate, gradually narrowing to acute point directed adorally (mandible
appearing rapacious) (Figs. 12, 22); ventral apical tooth greatly reduced, scarcely
noticeable (Figs. 12, 21, 22); ventral edge of apical concavity sharply dened by ne
ridge, which toward base bears short series of small tubercles (Fig. 12, 21); dorsal
apical edge of concavity broadening slightly toward base and bearing large, ventrally
projecting tubercle and uneven surface at its base (Fig. 12); these elements presum-
ably homologue of mandibular cusp. Cardo and stipes sclerotized but unpigmented.
Prementum moderately small in frontal view. Salivary lips weakly projecting, only
about one-half as wide as distance between bases of labial palpi. Hypopharynx well
behind apices of articulating arms of stipes, low, questionably bilobed, faintly spicu-
late on both sides.
Material examined: 3 postdefecating larva: Trinidad: Maracas Valley, II-24-1966,
III-01-1966 (F.D. Bennett, J.G. Rozen); 1 predefecating larva: same except III-08-
1968 (J.G. and B.L. Rozen); 4 predefecating, 1 postdefecating larvae: Colombia: Valle
del Cauca: Cali I-10-1972 (C.D. Michener).
Mature Larva of Subtribe Emphorina
Description: Head (Figs. 8, 13): Apicolateral angles of epipharyngeal surface an-
gles with restricted swollen protuberances well separated from one another, each of
which is densely covered with short spicules; mandibular corium nonspiculate, except
clearly spiculate in Toromelissa nemaglossa and in some Diadasia. Integumental scle-
rotized areas, especially internal head ridges and sclerotized mouthparts, tending to be
more pigmented than those of Ancyloscelidina.
Apical part of mandible (including mandibular apex and all of cuspal area)
very darkly pigmented, almost black; line separating pigmented and nonpigmented
parts sharply dened as seen in dorsal (Figs. 24, 26, 28, 30, 32, 34) or ventral view.
Mandibular apex usually with two apical teeth; dorsal tooth larger, ventral tooth
slightly smaller (except approximately equal in Diadasina, Fig. 27, and in some
species such as Diadasia olivacea, Fig. 25, ventral tooth longer than dorsal one);

Descriptions of Mature Larvae of the Bee Tribe Emphorini and Its Subtribes... 287
dorsal apical mandibular edge without teeth; ventral mandibular tooth and ventral
edge of mandibular apex twisted adorally forming elongate oblique apical concav-
ity (Fig. 20) on adoral apical surface in conjunction with strongly produced dorsal
apical edge (Fig. 20); when viewed dorsally (Figs. 19, 34) ventral tooth appearing
more curved than dorsal tooth; adoral surface of cusp thick toward mandibular
base; leading cuspal edge linear, rounded (Ptilothrix), or narrowly planar (Melitoma,
Diadasia), without distinct spines, sometimes irregularly roughened or minutely
pebbled (e.g., Diadasia enavata, Fig. 24). Prementum moderately small to moder-
ately wide in frontal view. Salivary lips weakly to strongly projecting; width one-
half as wide, to as wide, as distance between bases of labial palpi. Hypopharynx well
behind apices of articulating arms of stipes, often dorsally projecting, in some cases
bilobed, spiculate on dorsal surface.
Material examined: Diadasia enavata: 10+ larvae, all stages: USA: Washintdon:
Yakima Co.: S of Granger, IX-5-1993 (E. Miliczky). D. olivacea: 3 predefecating last
larval instars: USA: Arizona: Cochise Co.: Southwestern Research Station, 5 mi S of
Portal, IX-7-1773 (J.G. Rozen, M. Favreau). D. rinconis: 10+ larvae, all stages: USA:
Arizona: Pima Co.: Arizona-Sonora Desert Museum, V-9-1987 (J.G. Rozen, S.L Bu-
chmann); 10+ mature larvae: same except: Catalina State Park, V.-8-1990 (S.L. Bu-
Figures 13–16. SEM micrographs of postdefecating larva of Diadasia rinconis. 13 Head, frontal view
14 Left mandible, showing setae on outer surface 15 Salivary lips, from above 16 Upper part of segment
10, posterior view.

Jerome G. Rozen, Jr. / ZooKeys 148: 279–291 (2011)
288
chmann). D. vallicola: 10+ late stage larvae: USA: California: Riverside Co.: 18 mi
W of Bythe, V-2-1991 (J.G. Rozen). Diadasina sp. 2 postdefecating larvae: Argen-
tina: Chaco Prov.: Capitan Solari, I-31-2006 (J. Straka). Melitoma grisella: 10+ vari-
ous larval instars: USA: Nebraska: Keith Co.: Cedar Point Biological Station, VII-20-
1988 (J.G. Rozen). M. marginella: 1 postdefecating larva: Mexico: Jalisco: Chemela,
XI-7-1986 (J.G. Rozen). M. segmentaria: 5 mature larvae: Trinidad: Nariva Swamp,
X-12-1965 (F.D. Bennett). Ptilothrix bombiformis: 2 cast larval skins: USA: Maryland:
Prince George Co.: Greenbelt, IX-21, 22-1986 (B. Norden). P. near sumichrasti: 3
mature lavae: USA: Arizona: Cochise Co.: 8 mi NE of Portal, VIII-18–24- 990 (J.G.
Rozen, J. Krieger). P. tricolor: 2 postdefecating larvae: Argentina: Tucumán Prov.: 11
km NW of Cadillal, XII-4-1993 (J.G. Rozen). Toromelissa nemaglossa: 10+ larvae of
all stages: Chile: Atacama Region(III): Huasco Prov. 37 km W of Domeyko, XI11-11-
2000 (J.G. Rozen).
Remarks: In Diadasia enavata (and perhaps in some other species in that genus) the
ventral apical mandibular tooth appears missing (Michener, 1953: Figs. 209, 210). Ex-
amination of an early stage last larval instar (Fig. 23) shows that it clearly present, but
in postdefecating forms it is worn away leaving the mandible with a broad, obliquely
truncate apex, bearing a large, adorally directed apical concavity.
Figure 17–20. SEM micrographs of mature larva of Melitoma grisella. 17 Left side of abdominal seg-
ment 10, posterior view 18 Antenna 19 Mandible, dorsal view, and 20 inner view.

Descriptions of Mature Larvae of the Bee Tribe Emphorini and Its Subtribes... 289
Figures 21–34. Right mandibles of mature larvae of Emphorini, showing inner view and dorsal view of
each representative, as labeled.

Jerome G. Rozen, Jr. / ZooKeys 148: 279–291 (2011)
290
Conclusions and discussion
Because all taxa whose immatures were examined in this study possessed most if not
all features of abdominal segments 9 and 10 described above, this character complex
strongly supports the relationship of Ancyloscelis with the Emphorina, despite the very
dierent mandibles of the two groups.
Except for mandibular morphology, there is a strong similarity among not only
larval Ancyloscelidina, as represented by Ancyloscelis apiformis, and larvae of Empho-
rina, but also larvae of Exomalopsini (Rozen, in press) and Tetrapediini (Rozen, et
al., 2006). ese similarities include: body shape (protruding venter on abdominal
segment 9, dorsally positioned anus, and paired low or virtually absent dorsal body
tubercles); spiracle morphology; and head features (excluding mandible morphology).
Acknowledgments
I thank the following persons for donation of specimens of taxa (in parentheses) used
here to the American Museum of Natural History (AMNH): Jakub Straka (Diadasina
sp.), Eugene Miliczky (Diadasia enavata), Fred Bennett (Melitoma segmentaria), and
Beth Norden (Ptilothrix bombiformis). ese donations added greatly to this investiga-
tion. I also thank Charles D. Michener for the loan of larval Ancyloscelis apiformis.
Heather M. Campbell, Curatorial Assistant, AMNH, prepared specimens for
SEM examination and took SEM micrographs in the Microscopy and Imaging Fa-
cility, AMNH. All illustrative material was arranged and labeled by Steve urston,
Senior Scientic Assistant, AMNH. Both Heather M. Campbell and John S. Ascher,
Bee Databasing Manager, AMNH, kindly reviewed the manuscript. I also extend my
appreciation to the three anonymous reviewers for their corrections and helpful com-
ments.
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