The Extinct Fauna of Stingless Bees (Hymenoptera: Apidae: Meliponini) in Dominican Amber: Two New Species and Redescription of the Male of Proplebeia dominicana (Wille and Chandler)

24 Pages·2000·0.7 MB·English

by  João M. F. Camargo

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PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY
CENTRAL PARK WEST AT 79TH STREET, NEW YORK, NY 10024
Number 3293, 24 pp., 22 figures, 1 table March 16, 2000
The Extinct Fauna of Stingless Bees
(Hymenoptera: Apidae: Meliponini)
in Dominican Amber: Two New Species and
Redescription of the Male of Proplebeia
dominicana (Wille and Chandler)
JOA˜O M.F. CAMARGO,1 DAVID, A. GRIMALDI,2 AND SILVIA R.M. PEDRO3
ABSTRACT
Seventeen specimens of Meliponini in Dominican Republic amber were studied, including
eight workers of Proplebeia dominicana and four males, presumably of this same species.
Detaileddescriptionsoftwonewspecies,placedtentativelyinProplebeia,areincluded.Char-
actersofthemale(mainlyshapeofsterna5and6)corroboratethehypothesisthatProplebeia
constitutes a distinct branch within the lineage of Neotropical Plebeia (s.s.). We discuss pos-
sible phylogenetic affinities among Plebeia, Proplebeia, and Nogueirapis silacea,thelatterin
amber from Chiapas, Me´xico.
INTRODUCTION Proplebeia.Onlyonespecies,P.dominicana
(Wille and Chandler), has been described,
Dominican amber is renowned for the probably because the other meliponines in
great diversity of organisms in it, and one of this amber are so rare and morphologically
the most common insects is a stingless bee, similar to P. dominicana as to have escaped
1,3DepartamentodeBiologia,FaculdadedeFilosofia,CieˆnciaseLetrasdeRibeira˜oPreto—USP,Av.Bandeirantes,
3900, 14040-901—Ribeira˜o Preto, SP, Brasil (JMFC is CNPq fellow researcher, Proc. 300014/84-8 RN); e-mail:
[email protected]/[email protected]
2Curator,Divisionof InvertebrateZoology,AmericanMuseumofNaturalHistory.e-mail:[email protected]
Copyright(cid:113)AmericanMuseumofNaturalHistory2000 ISSN0003-0082/Price$1.90
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2 AMERICAN MUSEUM NOVITATES NO. 3293
notice. Only Michener and Poinar (1996) described male specimens, presumably of P.
mentioned the existence of other undescribed dominicana (in Poinar’s personal collection,
species. Indeed, our description of the puta- numbers H10-52 and H10-94).
tive males of P. dominicana and two new In the present paper new data on workers
species is based on nine specimens out of and putative malesofP.dominicanaarepre-
several thousands of Proplebeia examined sented with the description of two new spe-
over the past decade by Grimaldi. The abun- cies.
dance and manageable size of amberProple-
beia have made them favored subjects for MATERIALS AND METHODS
studies on internal ultrastructural preserva-
tion (Grimaldi et al., 1994), DNA, and other Seventeen pieces of Dominican Republic
macromolecules (Cano et al., 1992a, 1992b; amber, each containing one specimen ofMe-
Walden and Robertson, 1997; Stankiewiczet liponini, except the piece AMNH-DR-14-
al., 1998). Proplebeia is certainly one of the 1439 with one complete specimen and two
most intensively studied of all fossils, but fragments, were examined. The pieces are
discovery of very similar species indicates deposited in the American Museum of Nat-
that even such fundamental aspects as iden- ural History (AMNH—14 pieces),andinthe
tity and diagnosis, as well as phylogenetic NaturalHistoryMuseumoftheUniversityof
relationships, require clarification. The nu- Kansas (3 pieces). All specimens came from
merous studies cited above and below pre- commercial dealers who exclusively market
sumably refer to P. dominicana, since the Dominican amber. As such, it is impossible
new species constitute less than 0.1% of all to know the exact mine from which any one
stingless bees found in Dominican amber. piece originated. Copal—hardened resin
Proplebeia dominicana was originally from moderntrees,onlyseveralyearstosev-
placed by Wille and Chandler (1964) in the eral thousand years old—occurs in the Cotui
genus Liotrigona, a modern group endemic region of the Dominican Republic, but this
to Africa and Madagascar (Moure, 1961; material is visually very obvious and no me-
Moure and Camargo, 1978; Michener, 1982, liponines have ever been found in it. It is
1990; Brooks and Michener, 1988). Moure derived from the living tree Hymenaeacour-
and Camargo (1978), using the original de- baril,whichoccursthroughouttheCaribbean
scription of P. dominicana and a superficial and Central America. True amber, which is
examination of some specimens (probably a usually darker, harder, and much more po-
distinct species), suggested the inclusion of lymerized and inert than copal, comes from
P. dominicana in the Neotropical genus Ple- mines in the Cordillera Septentrional just
beia (s.s.). Michener (1982), who examined north and east of Santiago. It isderivedfrom
98 specimens and compared them with Ple- an extinct Hymenaea species possibly most
beia and Liotrigona, did not find derived closely related to the east African speciesH.
characters (synapomorphies) to supportplac- verrucosa.
ing P. dominicana in one of these two gen- Unfortunately, published ages of Domini-
era. In order to avoid taxonomic ‘‘artificial- canamberhavebeenunnecessarilyconfused.
ities,’’ he proposed a new subgenus for this Earlier publications have claimed the mate-
species: Proplebeia, at that time subordinate rial to be between Lower Miocene (ca. 23
to Trigona (s.l.). The name proposed by Ma) to even Upper Eocene (ca. 40 Ma) in
Michener reflected his belief in a close re- age (e.g., Poinar and Hess, 1982; Poinar,
lationship between Proplebeia and Plebeia 1994a).Inparticular,minesfromtheLaToca
(s.s.):‘‘...TheplacementofProplebeianear region have been claimed to be older (Eo-
Plebeia by Michener (1982) still seems rea- cene) than other amber deposits in the Do-
sonable’’ (Michener, 1990: 107). Michener minican Republic (Lambert et al., 1985), but
(1990) also described other characters from this dating is based on molecular analysesof
the sting apparatus of P. dominicana, which the amber, which have been shown to be er-
are shared with American genera and not roneouslyinterpreted(Grimaldi,1995).Inre-
with Liotrigona or any other African group. ality, based on the most comprehensive
Michener and Poinar (1996) superficially stratigraphic study done thus far (Iturralde
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2000 CAMARGO ET AL.: STINGLESS BEES IN AMBER 3
and MacPhee, 1996), Dominican amber is grateful to Roy Larimer, Jacob Brodzinsky,
from the lower part of the Mid Miocene to and Manuel Perez, for providing specimens
the uppermost part of the Lower Miocene, to the AMNH; and to Robert Goelet, trustee
ca. 15–20 Ma. This date is corroborated by and Chairman Emeritus of the AMNH, for
the apparent recency of organismal inclu- funds to acquire specimens.
sions, which are not as plesiomorphic as
most species preserved in older, Eocene am- SYSTEMATICS
ber from the Baltic (e.g., Grimaldi, 1995,for
GENUS PROPLEBEIA MICHENER
Diptera; Engel, 2000, for bees). Also, com-
Figures 1–22
prehensive unpublished analyses using py-
rolysis-gas chromatography (Shedrinsky and Trigona (Proplebeia) Michener, 1982: 44. Type-
Grimaldi, unpubl.) show no consistent vari- species Trigona (Liotrigona) dominicana Wille
and Chandler, 1964, by original designation.
ationinDominicanamberregardlessofmine
source, suggestive of origins that are botan- DIAGNOSIS: Small bees; body length 2.0–
ically identical and contemporaneous. 4.4 mm. Generalbody form,legsandpattern
Despite an age that is younger than pre- of wing venation as in Plebeia (s.s.). Differs
viously believed, Dominican amber remains from Plebeia principally by broad, smooth,
averysignificantsourceoffossilinsects,one depressed posterior margin of the inner sur-
reason being its preservative qualities— face of tibia III (2⁄ to ⅓ the width of keiro-
7
probably better than any other amber (Gri- trichiate area; in Plebeia ca. 1⁄ to 1⁄ ), rastel-
6 5
maldi et al., 1994). Proplebeia bees in this lum with 7–9 long, cylindrical, spinelike
amber have been found with intact internal hairs, and S6 of male with long, broad me-
organs(includingcropsfilledwithpollen),as dian projection (in Plebeia, the projection of
well as subcellular (ultrastructural) details. S6 reduced or absent).
Dominican amber is also the only significant
source of Cenozoic insect fossils in the Ca- Proplebeia dominicana (Wille and
ribbean, and has revealed startling examples Chandler)
of extinctions in this region, of which the Figures 1–7, 9
meliponine bees are a prime example.
Trigona(Liotrigona)dominicanaWilleandChan-
Thespecimenswerepreparedaccordingto
dler, 1964:187–195 (tax., description).
the procedures in Grimaldi(1993).Drawings Trigona (Hypotrigona) dominicana; Morris, in
were made with the aid of a Wild M5A and ZeunerandManning,1976:256(fossilreview).
camera lucida with magnification up to Trigona dominicana; Wille, 1977: 44 (fossil re-
106(cid:51). Measurements were taken with anoc- view, tax. notes); 1979: 269 (tax. notes). –
ularreticuleandarepresentedinmillimeters. Michener, 1979: 322 (biogeogr., tax. notes).
Morphological terminology follows Miche- ? Trigona (Plebeia) black species; Wille, 1979:
269 (tax. notes).
ner (1944, 1990) and Camargo et al. (1967).
Plebeia dominicana; Moure and Camargo, 1978:
The term mesosoma refers to the usual seg-
563–564 (tax. notes, new combination).
ments of thorax plus the first abdominal seg-
Trigona (Proplebeia) dominicana; Michener,
ment, the propodeum. Segments 2–9 of the
1982: 37–45 (not published in this form but
abdomen are referred to as 1–8 of the me- stated to be a Trigona; tax. notes, new subge-
tasoma (T1 (cid:53) second abdominal tergum, S1 nus).
(cid:53) second abdominal sterna, etc). The legs Trigona A, B, C; Michener, 1982: 41–42 (tax.
are indicated with Roman numerals:I,II,III. notes).
Proplebeia dominicana; Camargo et al., 1988:
153 (biogeogr. notes). – Camargo, 1989: 44
ACKNOWLEDGMENTS
(tax.notes).–Michener,1990:87,95,105–107
(tax.notes,phylogeny).–Ayala,1992:60(bio-
JMFC and SRMP thank Fernando Zanella
geogr. notes). – Roubik, 1992: 499, 503 (figs.
and Gabriel AR Melo for commentsandcor-
tibia). – Cano et al., 1992a: 249–251 (DNA);
rections of language and style on the early
1992b: 619–622 (RNA). – Poinar, 1992: 466–
manuscript. Michael Engel and an anony- 468 (resin collection); 1994a: 537-538 (DNA);
mous reviewer provided very useful com- 1994b:73–75(fossilreview,symbioticandpar-
mentary on the manuscript. We are also asiticassociations).–Grimaldietal.,1994:12–
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4 AMERICAN MUSEUM NOVITATES NO. 3293
Figs. 1, 2. Proplebeia dominicana; 1. male, specimen AMNH-DR-14-1178; 2. worker, specimen
AMNH-DR-14-1111. Scale (cid:53) 1.0 mm.
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14 (electron microsc.). – Grimaldi, 1996a: 72– layers of air bubbles, striations, or the posi-
73(electronmicrography);1996b:118(figures, tion of cuts in the amber piece hinder a cor-
paleoecology). – Michener and Poinar, 1996: rect judgement. Also, specimen DR-14-1173
360–361 (fossil review, tax. notes, description
is too deformed and discolored. The yellow
of male P. dominicana). – Walden and Robert-
maculations in the lower parocular areas,
son, 1997: 1075–1077 (DNA). – Carpenterand
clypeus, and supraclypeal area are clearly
Grimaldi, 1997: 6 (biogeogr. notes). – Stan-
visible (fig. 2) in all specimens exactly as
kiewicz et al., 1998: 642–645 (preservation in
resin). described and illustrated by Wille and Chan-
dler.
DIAGNOSIS: Worker. Body length ca. 3.0 There is disagreement between our speci-
mm; forewing length 2.50-2.75 mm; malar mens and some structural characters men-
area short, ca. ½ the diameter of scape; yel- tioned by Michener (1982): the rastellum
low stripe on parocular areas extending comprises seven to nine long, well differen-
above the antennal alveolus; emargination tiated, and apparently cylindricalbristles(ca.
between mandibular denticles deep. Male. 0.09–0.10 mm), concentrated in the anterior
Integument black, smooth, and shiny; body corner of the inner side of the distal border
length ca. 3.68 mm; flagellomeres ca. 1.7(cid:51) of tibia, behind thetarsalarticulation(fig.4);
longer than wide; S6 with long, wide, me- thepenicillum(fig.3)isnormalasinPlebeia
dian projection, enlarged and bifid apically; (s.s.) and Nogueirapis, and it is not as long
S7 with a row of long hairs along the distal and parallel to the longitudinal axis of the
margin; gonostyli long, slender, and slightly tibia as was indicated by Michener (1982).
broadened at apex. In the less deformed specimens it is possible
The species was interpreted based on the to see that the propodeum is not as vertical
original description of Wille and Chandler, as it seems in the drawing presented by
which is very detailed in relation to both su- Michener (1990: 105, fig. 83), the slope be-
praspecific and specific characters, and also ing gentle as in Plebeia (s.s.). The width of
on additional data provided by Michener the keirotrichiate area, measured approxi-
(1982). Wille and Chandler presented the mately at the middle of the tibia (specimen
measurements,exceptlengthofthebodyand DR-14-1175), is 0.20 mm and the bare, de-
forewing, in units of the eyepiece reticleand pressed posterior rim is 0.06 mm wide. The
there is no indication of the index of con- limit between the keirotrichiate area and the
version into millimeters. In his 1979 paper depressed posterior rim is clearly defined by
(p. 269), Wille presented the conversion into a step (fig. 4). The malar area is not linear,
millimeters of the depressed posterior rim its length being approximately equal to half
and keirotrichiate area width of tibia IIIas3: the diameter of the scape.
9 units (cid:53) 0.099: 0.297 mm, which is obvi- Wille (1979: 269) referred to some black
ously wrong. If the same proportion is ap- specimensasPlebeia(s.s.).Michener(1982:
plied to the head width, we have 72 (cid:53) 2.376 41), who examined these same specimens,
mm (!), which is only alittleshorterthanthe considered them to be Proplebeia, possibly
length of the forewing (2.60 mm). However, a species distinct from P. dominicana. How-
in another text Wille (1964) indicated on ever, Michener and Poinar (1996: 354) re-
page 123 (footnote) a conversion factor of 1 ferred to them only as color morphs of P.
unit (cid:53) 0.017 mm, which results in measure- dominicana. We examined the specimens
ments more similar to ours and which were mentioned by Michener (1982, Trigona A,
used for comparisons in this study (table 1). B, C, specimens of KansasUniversity,Brod-
Color of integument, punctation, pubes- zinsky coll.) and consider them conspecific
cence, and size of the specimens examined with P. dominicana.
agree perfectly with the description of Wille DESCRIPTION: Male. Based on specimen
andChandler.Theyellowstripesonthesides DR-14-1178,anddetailsofgenitaliaandpre-
ofthemesoscutum(0.06mmwide)areclear- genital sterna of DR-14-954. Amber piece
ly visible only in specimen DR-14-1179; on DR-14-1178 was cut in right angles that al-
the scutellum it is not possible to distinguish lowed examination in several positions.
a yellow stripe in any of the specimens; thin There are some bubbles, fractures, and fis-
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6 AMERICAN MUSEUM NOVITATES NO. 3293
TABLE1
Measurements (mm) of Select Specimens of Proplebeia dominicana
Holotype measurements are from the original descriptions by Wille and Chandler (1964).
MaleDR-14-1178 WorkerDR-14-1111 Holotype,worker
1. Headwidth 1.31 1.30 1.22 (72)
2. Headlength 1.00 1.02 —
3. Mesosomawidth 1.28 — —
4. Tergum2 width 0.98 — —
5. Eyelength 0.84 0.84 0.80 (47)
6. Eyewidth 0.40 0.36 —
7. Upperinterorbitaldistance 0.75 0.84 0.76 (45)
8. Maximuminterorbitaldistance 0.78 0.89 0.82 (48)
9. Lowerinterorbitaldistance 0.50 0.68 0.65 (38)
10. Clypeuslength 0.34 0.23 —
11. Clypeuswidth 0.48 0.54 —
12. Clypeocellardistance 0.64 0.70 —
13. Malararealength linear 0.04 0.05 (3)
14. Interalveolardistance 0.13 0.16 0.15 (9)
15. Alveolusdiameter 0.14 0.14 0.12 (7)
16. Alveolorbitaldistance 0.10 0.16 0.17 (10)
17. Scapelength 0.38 0.40 —
18. Scapewidth 0.08 0.08 —
19. Lengthofpedicelplusflagellum 1.66 — —
20. Alveolus-lateralocellusdistance 0.55 0.58 0.65 (38)
(lateralocellus?)
21. 1stflagellomerelength 0.16 — —
22. 2ndflagellomerelength 0.15 — —
23. 3rdflagellomerelength 0.15 0.08 —
24. 3rdflagellomerediameter 0.09 0.08 —
25. Distancebetweenlateralocelli 0.34 0.26 —
26. Medianocellusdiameter 0.14 0.11 0.10
27. Ocellorbitaldistance 0.11 0.18 0.17 (10)
28. Scutellumlength:width 0.28:0.50 0.26:0.44 —
29. Mesoscutumlength — 0.80 —
30. Marginalcelllength 0.91 0.92 —
31. Marginalcellwidth 0.20 0.21 —
32. Forewinglength 2.75 2.68 2.60
((cid:49)tegula3,12)
33. Forewingwidth 0.96 1.08 —
34. TibiaIIIlength 0.92 0.96 —
35. TibiaIIIwidth 0.30 0.37 —
36. BasitarsusIIIlength 0.52 0.42 —
37. BasitarsusIIIwidth 0.12 0.19 —
38. Hamuli 5–6 5 —
39. Pterostigmalength:width 0.44:0.12 0.50:0.12 —
40. 1stabscissaofM 0.38 0.39 —
41. 1stabscissaofCu 0.54 0.56 —
42. Rs(cid:49)M(cid:49)2ndabscissaM 0.36 0.40 —
43. Totalbody length 3.68 3.20 2.95
sures, but the bee is well preserved (figs. 1, bytheresin.Dimensions:Approximatebody
5), practically without deformation, which length 3.68 mm, forewing length, from apex
permitted virtually exact measurementstobe of costal sclerite to wing tip 2.75 mm (in-
made. The bubbles over the spiracles (fig. 5) cluding tegula, 3.00 mm); maximum head
indicate that the bee was quickly immersed width 1.31 mm; metasoma width 0.98 mm
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Figs.3,4. Proplebeiadominicana,tibiaIII.3.outersurface,specimenAMNH-DR-14-1179;4.inner
surface, detailof the keirotrichiate area andrastellum,specimenAMNH-DR-14-1175.Scale(cid:53)1.0mm.
(figs. 1, 5). Color of integument: Black, mesoscutum, increasing in length ventrad
lacking yellow markings except for one (0.12–0.6 mm). Basal area of propodeum
translucent spot on either side of the base of glabrous. Posterior edge of tibia III with un-
the scutellum (exactly as in worker DR-14- branched hairs (ca. 0.12 mm long). T1-4
1111). Lower parocular area and distal edge without perceptiblepilosity,exceptsomemi-
of clypeus somewhat lighter, without yellow nute hairs laterally; sides of T5-7 with erect,
markings (specimen DR-14-954 is entirely unbranched hairs, denser and progressively
black). Tarsi of all legs and wing veins light longer on T6-7; the longest hairs on distal
chestnut. Wing membrane hyaline. Pilosity: border of T7 0.14 mm. It was not possible
Pale yellow over entire body. Decumbent, toobserveindetailthesternalpilosityinany
minute hairs covering whole face; vertex of the specimens; only in DR-14-954 it is
with unbranched erect hairs, longest hairs possible to see a row of erect unbranched
0.16 mm. Mesoscutum with sparse, slender, hairs ca. 0.10 mm long, arranged regularly
erect hairs, the longest ones on anterior cor- along the distal edge of S5 (figs. 6, 7). In-
nersca.0.18mmandthoseonposterioredge tegument: Smooth and shiny, except for
of scutellum ca. 0.20 mm (fig. 5). Pubes- some sparse piligerous punctures. Punctures
cence on mesepisterna a little denser thanon of head dense, owing to the dense micropi-
ATA
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Fig. 5. Proplebeia dominicana, male, specimen AMNH-DR-14-1178. Scale (cid:53) 1.0 mm. 3 M
2 0
9 1p
3 c_
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2000 CAMARGO ET AL.: STINGLESS BEES IN AMBER 9
losity, distance between punctures ca. 1 to figures6,7.S5unmodified,exceptforslight-
2(cid:51) puncture diameter. Mesoscutum shiny, ly concave distal border (with a transverse
with large spaces among bases of hairs (3 to row of hairs); S6 with long, wide median
4(cid:51) puncture diameter). Metasomal terga projection [(cid:53) apical process (Michener,
smooth and shiny. Form and proportions: 1990)], enlarged and bifid apically (figs. 6,
Head wider than long (1.31: 1.00, length 7); visible portion of S7 strongly sclerotized.
measured from apex of clypeus to uppertan- Genitalia of specimen DR-14-954 is in trig-
gent of median ocellus), approximately as gered conformation, with penis valves di-
wide as mesosoma (1.28, measured across
rected laterally (as occurs during copulation
mesepisterna)andwiderthanT2(0.98).Eyes
in extant Meliponini), making study of cer-
2.1(cid:51) longer than wide (0.84: 0.40) and con-
tain structures difficult; gonocoxites not en-
vergent below; upper interorbital distance
tirely visible nor is an unequivocal spatha.
0.75,maximumdistance0.78,andlowerdis-
Penis valves very long (0.67 long per 0.11
tance 0.50. Malar area linear. Clypeus 1.4(cid:51)
wide at base), rather arched and pointed api-
widerthanlong(0.48:0.34),slightlyconvex;
cally; gonostylus long and slender, exposed
epistomalsuturealmoststraightonsides(fig.
portion 0.61 long, 0.02 wide at its slightly
1). Labrum normal, slightly convex. Clypeo-
broadened apex (figs. 6, 7).
cellar distance 0.64. Interalveolar distance
nearly equal to diameterof antennalalveolus MATERIALEXAMINED:Fourmales,AMNH-
DR-14-1178, DR-14-954, DR-14-1174 and
and slightly largerthanalveolorbitaldistance
DR-14-812; eight workers, AMNH-1 DR-
(0.13: 0.14: 0.10). Frons slightly depressed
along median line. Distance between lateral 14-1111, DR-14-1173, DR-14-1175, DR-14-
ocelli ca. 2.4(cid:51) diameter of median ocellus 1176, DR-14-1179 (these selected as partic-
and 3.1(cid:51) ocellorbital distance (0.34: 0.14: ularly well preserved) and threeunnumbered
0.11). Vertex behind ocelli rounded; preoc- ones from the Natural History Museum of
cipital ridge slightly rounded. Scape length the University of Kansas, Snow Hall (Brod-
4.75(cid:51)itsdiameter(0.38:0.08)andca.2⁄ dis- zinsky coll.); all fromtheDominicanRepub-
3
tance between antennal alveolus and lateral lic, as described under Materials and Meth-
ocellus (0.55). Flagellum plus pedicel (1.66) ods.
ca. 4(cid:51) length of scape; flagellomeres ca. REMARKS: We tentatively interpreted the
1.7(cid:51) longer than wide (the second one 0.16: specimens listed above as males of P. dom-
0.09).Scutellumindorsalviewanequilateral inicana. The males are very similar to the
arch with rounded apex, 1.8(cid:51) wider than workers in size, conformation of the wing
long (0.50: 0.28) (it is possible that the scu- veins, and the yellow markings on the base
tellum is a little deformed because of dehy- of scutellum. The wings are the only struc-
dration in the amber). Forewing 2.9(cid:51) longer tures that usually do not exhibit sexual di-
thanwide(2.75:0.96);pterostigma3.6(cid:51)lon-
morphism in Meliponini. Even for most ex-
gerthanwide(0.44:0.12);marginalcelllong
tant species, it is only possible to associate
and narrow (0.91: 0.20), its apex open;angle
sexes with confidence when they are collect-
between Rs and Rs (cid:49) M slightly acute (ap-
ed together in the nest.
proximately 85(cid:56)); first abscissa of M ca. 5⁄
7 ThemainautapomorphiesofmaleP.dom-
length of first abscissa of Cu (0.38: 0.54),
and practically as long as Rs (cid:49) M (cid:49) second inicana are: very long flagellomeres, ca.
1.7(cid:51)longerthanwide(MichenerandPoinar,
M. First submarginal cell almost entirely
1996,mentioned3(cid:51)longerthanwide,which
open, second abscissa of Rs forming a small
does not correspond to their figure 8, p. 357,
projection. Second submarginal cell com-
pletely absent. Hamuli, 5–6. Tibia III sub- where the proportion is ca. 2:1),S6withme-
triangular,3.1(cid:51)longerthanwide(0.92:0.30) dianprojectionverylongandbroad,andapi-
slightly biconvex, posterodistal corner cally bifid, and S7 with a row of long hairs
rounded. Basitarsus III 4.3(cid:51) longer than along the distal margin [superficially similar
wide (0.52: 0.12), flattened, lateral margins to Austroplebeia symei (Rayment, 1932)].
subparallel,distaledgeinrightangle.Details Other comments are given under P. tantilla
of the genitalia and pregenital sterna as in Remarks, and under Discussion below.
AMNHNOVITATES novi 00145 Mp_10
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10 AMERICAN MUSEUM NOVITATES NO. 3293
Figs. 6, 7. Proplebeia dominicana, genitalia of male, posterior view and profile, specimen AMNH-
DR-14-954; S5–S7 (cid:53) 5th–7th metasomal sterna, respectively. Scale (cid:53) 1.0 mm.