A revision of the subgenus Osmia (Diceratosmia), with descriptions of four new species (Hymenoptera, Megachilidae)
Author
Rightmyer, Molly G.
text
Zootaxa
2017
2017-10-17
4337
1
1
37
journal article
31832
10.11646/zootaxa.4337.1.1
d7147fd1-b46c-435d-8b08-f6e46ef6e3c4
1175-5326
1014033
39A92904-0378-4B5D-AE6F-704E5B38A59C
Osmia
(
Diceratosmia
)
conjunctoides
Robertson
(
Fig. 1C
)
Osmia conjunctoides
Robertson 1893
: 276
[
Lectotype
male: Champaign];
Sandhouse 1939
: 140
[synonymy with
O
.
subfasciata
]; LaBerge (in
Webb 1980
): 118 [
lectotype
designation];
Rightmyer
et al
. 2011
: 270
[rejection of synonymy with
O
.
subfasciata
].
Diceratosmia subfasciata conjunctoides
(Robertson)
;
Michener 1949
: 264
.
Osmia
(
Diceratosmia
)
subfasciata miamiensis
Mitchell 1962
: 84
[Holotype female: Washington, D.C.];
Rightmyer
et al
. 2011
: 270
[synonymy].
Diagnosis.
Females of this species are distinguished from all other
Diceratosmia
by the nearly uniformly short, straight to distally curved hairs on the clypeus. These hairs are slightly longer and less uniform on the frons. These clypeal hairs are very similar to those of
Osmia
(
Melanosmia
)
calaminthae
Rightmyer, Ascher & Griswold
; however, in
O. calaminthae
the punctures of the metasomal terga are smaller, there is no carinate ridge on the hind coxa, and the parapsidal line is punctiform.
Osmia conjunctoides
has historically been confused with
O
.
subfasciata
; in addition to the diagnostic facial hair of
O
.
conjunctoides
noted above, females of these two species may be distinguished by differences in the scopal hairs.
In
O
.
conjunctoides
, the scopal hairs are tapered at their apical tips, while in
O
.
subfasciata
the scopal hairs are blunt, widened and slightly rounded at their apical tips (
Fig 12A
).
Males of
O
.
conjunctoides
are extremely similar to
O
.
subfasciata
, as these are the only known species of
Diceratosmia
in which the hairs on the apical margin of S4 are short, stout, and form an apical comb. In addition to generally being slightly larger (body length ca.
8–9 mm
vs.
6–7 mm
) and bluer bee than the greenish-blue
O
.
subfasciata
,
O
.
conjunctoides
is distinguished from that species by several subtle but consistent features: the mesoscutum is more finely and densely punctate relative to the scutellum (
O
.
conjunctoides
with ca. 16 punctures between parapsidal line and midline, these punctures distinctly smaller than those on the scutellum;
O
.
subfasciata
with ca. 11 punctures between parapsidal line and midline, these punctures about the same size as those on the scutellum). In dorsal view, T1 of
O
.
conjunctoides
is less concave along its anterior margin, while in
O
.
subfasciata
the anterior margin is strongly curved, forming anterolaterally rounded corners.
In
O
.
conjunctoides
, the lower propodeal triangle tends to be weakly shagreened throughout, while in
O
.
subfasciata
the lower propodeal triangle tends to be shiny.
Distribution.
Southern Florida north to
Georgia
(St. Catherines Island) and Mississippi (Forrest County) (
Fig. 18
).
Floral Associations.
Fabaceae
:
Crotalaria
.
Comments.
Males of this species are extremely similar to those of
O
.
subfasciata
; although previous workers were able to detect differences in the males that merited subspecific recognition (
Michener 1949
,
Hurd & Michener 1955
), recent examination of the associated females has allowed us to recognize more distinctive characters and to justify recognizing
O
.
conjunctoides
as species separate from
O
.
subfasciata
(
Rightmyer
et al
. 2011
)
.