Revision of the Nearctic species of the Lasioglossum (Dialictus) gemmatum species complex (Hymenoptera: Halictidae)
Author
Gardner, Joel
AA15FE6E-921A-46D6-BC67-88E067F283D9
Department of Entomology, University of Manitoba, 12 Dafoe Rd., Winnipeg, R 3 T 2 N 2, Manitoba, Canada.
clickbeetle3364@gmail.com
Author
Gibbs, Jason
BA42A49F-3EBC-4679-8F03-A58E798106B1
Department of Entomology, University of Manitoba, 12 Dafoe Rd., Winnipeg, R 3 T 2 N 2, Manitoba, Canada.
jason.gibbs@umanitoba.ca
text
European Journal of Taxonomy
2023
2023-02-10
858
1
1
222
http://zoobank.org/d760cf56-dda7-4a35-9a2b-bf1f7e59f313
journal article
265947
10.5852/ejt.2023.858.2041
53d813c3-9674-4b65-9cdc-2ec09ecc445c
2118-9773
7629347
D760CF56-DDA7-4A35-9A2B-BF1F7E59F313
Lasioglossum
(
Dialictus
)
stictaspis
(
Sandhouse, 1923
)
Figs 60–
66
,
76O
,
81C
,
89B
,
91A
,
100B
,
111B
,
112B
,
114B
Dialictus stictaspis
Sandhouse, 1923: 195
(
holotype
,
♂
, deposited in USNM, examined).
Halictus
(
Chloralictus
)
albuquerquensis
Michener, 1937: 316
(
holotype
,
♀
, deposited in CAS, examined).
Lasioglossum
(
Dialictus
)
stictaspis
–
Michener 1951: 1119
(catalogue).
Lasioglossum
(
Chloralictus
)
albuquerquense
–
Michener 1951: 1112
(catalogue).
Dialictus stictaspis
–
Hurd 1979: 1971
(catalogue). —
Moure & Hurd 1987: 131
(catalogue).
Dialictus albuquerquensis
–
Hurd 1979: 1964
(catalogue). —
Moure & Hurd 1987: 89
(catalogue).
Diagnosis
See the diagnosis for the
L. stictaspis
species complex and the diagnosis for
L. paululum
. Females of
L. stictaspis
s. str.
, described from
New Mexico
, have the tegula relatively large (reaching and sometimes slightly exceeding posterior margin of mesoscutum in dorsal view), with inner posterior margin weakly concave, and densely punctate (IS ≤ 1 PD); metapostnotum dull, tessellate to finely reticulate, and usually with fine subparallel rugae; mesepisternum shiny (sometimes with weak microsculpture) and densely punctate (IS <1 PD); mesoscutum dull and coarsely punctate (2–3 punctures between posterior end of parapsidal line and/or lateral edge of mesoscutum and some IS = 1–2 PD between parapsidal lines); T1–T2 discs finely and moderately sparsely punctate (IS = 1–3 PD) and apical rims impunctate; T3 with dense subapical band of tomentum (often medially interrupted); face short (length/width ratio ≤0.83) and gena narrower than eye in lateral view.
Females of
L. stictaspis
s. str.
are most similar to those of
L. angelicum
sp. nov.
,
L. diabolicum
sp. nov.
,
L. ellisiae
,
L. gaudiale
, and
L. pseudotegulare
. Females of
L. angelicum
and
L. pseudotegulare
have the T1–T2 discs more deeply and densely punctate (IS = 1–2 PD) with some punctures often extending onto apical rims. In addition, females of
L. angelicum
have the metapostnotum shiny with strong anastomosing rugae, and females of
L. pseudotegulare
have the face slightly longer (length/width ratio usually>0.83). Females of
L. ellisiae
have the tegula slightly smaller (not exceeding posterior margin of mesoscutum in dorsal view) and usually more sparsely punctate (up to IS = 1–3 PD), metapostnotum with strong, coarse rugae and basal half shiny, and T3 usually without subapical tomentum (rarely with a sparse, broadly interrupted band). Females of
L. gaudiale
have the metapostnotum with strong, coarse rugae and basal half shiny, gena about as wide as eye in lateral view, and T3 without subapical tomentum.
Males of
L. stictaspis
s. str.
have the tegula densely punctate (IS ≤ 1 PD), relatively large (slightly exceeding posterior margin of mesoscutum in dorsal view), and inner posterior margin concave, with a small rounded posterior projection about 0.5 lateral OD in size; metapostnotum tessellate to finely reticulate with shallow subparallel rugae; mesepisternum densely punctate (IS <1 PD); mesoscutum coarsely and moderately densely punctate (IS = 1–2 PD); disc of T2 with punctures deep, distinct, and usually dense (IS ≤ 1 PD); and T1–T2 apical rims impunctate.
Males of
L. stictaspis
s. str.
are most similar to those of
L. angelicum
sp. nov.
,
L. diabolicum
sp. nov.
,
L. ellisiae
, and
L. pseudotegulare
. Males of
L. angelicum
and
L. pseudotegulare
have the T1–T2 apical rims punctate; in addition, males of
L. pseudotegulare
have the T2 disc even more densely punctate medially(IS <1 PD). Males of
L. diabolicum
and
L. ellisiae
have the tegula slightly smaller (not exceeding posterior margin of mesoscutum in dorsal view) with inner posterior margin straight or sinuous and a blunt posterior angle or point narrower than 0.5 lateral OD, and usually more sparsely punctate in part (IS ≥1 PD); in addition, males of
L. ellisiae
have the mesoscutum more uniformly and densely punctate (IS ≤1 PD).
Lasioglossum stictaspis
s. lat.
is highly variable and a large number of specimens, especially those from south or west of
New Mexico
, may lack one or more of the above diagnostic characters, making them very difficult to separate from similar species.
Etymology
Sandhouse (1923)
formed the specific epithet ʻ
stictaspis
ʼ from the Greek adjective ʻ
stiktos
ʼ (punctured, spotted) and the noun ʻ
aspis
ʼ (shield). It likely refers to the punctured tegula of this species.
Range
Western Great Plains and Rio Grande River valley (
L. stictaspis
s. str.
) and west to
California
, south throughout
Mexico
(
L. stictaspis
s. lat.
).
DNA barcodes
Twenty-four confirmed sequences available, three haplotypes (BOLD process IDs: DLIII224-20, DLIII225-20, DLIII227-20 (haplotype 1); DLIII231-20, NCBEE336-21, NCBEE339-21, NCBEE343-21, NCBEE347-21, NCBEE349-21, NCBEE357-21, NCBEE369-21, NCBEE404-21, NCBEE407-21, NCBEE412-21 (haplotype 2); DLIII124-18, DLIII128-19, DLIII129-19, DLIII130-19, DLIII131-19, DLIII132-19, DLIII135-19, DLIII136-19, NCBEE403-21, SMTPP733-15 (haplotype 3)). Haplotypes 2 and 3 are shared with
L. diabolicum
sp. nov.
Haplotype 3 has some relatively deep divergence and may be possible to split into additional haplotypes. No fixed nucleotide substitutions distinguish all
L. stictaspis
from all other Nearctic species of the
L. gemmatum
complex, but one fixed substitution distinguishes haplotype 2: 402(G) (Supp. file 2).
Fig. 60.
Lasioglossum
(
D
.)
stictaspis
(
Sandhouse, 1923
)
, ♀, holotype of
L
.
(
D
.)
albuquerquense
Michener, 1937
(CAS).
A
. Dorsal habitus.
B
. Lateral habitus.
C
. Face. Scale bars = 1 mm.
Fig. 61.
Lasioglossum
(
D
.)
stictaspis
(
Sandhouse, 1923
)
, ♀, Colorado morph (reproduced from
Gardner & Gibbs 2022
) (UCMC).
A
. Lateral habitus.
B
. Dorsal habitus.
C
. Face.
D
. Metasoma and propodeum. Scale bars = 1 mm.
Fig. 62.
Lasioglossum
(
D
.)
stictaspis
(
Sandhouse, 1923
)
, ♀, red-tailed morph.
A
. Dorsal habitus.
B
. Lateral habitus.
C
. Face.
D
. Metasoma and propodeum. Scale bars = 1 mm.
Fig. 63.
Lasioglossum
(
D
.)
stictaspis
(
Sandhouse, 1923
)
, ♀, Mexico morph (WRME).
A
. Dorsal habitus.
B
. Face.
C
. Lateral habitus.
D
. Metasoma. Scale bars = 1 mm.
Fig. 64.
Lasioglossum
(
D
.)
stictaspis
(
Sandhouse, 1923
)
, ♂, holotype (USNM) (except C, which is a Colorado specimen) (reproduced from
Gardner & Gibbs 2022
).
A
. Dorsal habitus.
B
. Lateral habitus.
C
. Face.
D
. Metasoma and propodeum. Scale bars = 1 mm.
Fig. 65.
Lasioglossum
(
D
.)
stictaspis
(
Sandhouse, 1923
)
, ♂, red-tailed morph.
A
. Dorsal habitus.
B
. Lateral habitus.
C
. Face.
D
. Metasoma. Scale bars = 1 mm.
Fig. 66.
Lasioglossum
(
D
.)
stictaspis
(
Sandhouse, 1923
)
, ♂, Mexico morph (WRME).
A
. Lateral habitus.
B
. Dorsal habitus.
C
. Face.
D
. Metasoma and propodeum. Scale bars = 1 mm.
Comments
The species treated by
Gardner & Gibbs (2022)
as
L. stictaspis
may include two species, the other one being
L. paululum
, described from Colorado. See that work for specimen records and range map. Specimens with a duller mesoscutum and ocellocular area, yellowish pubescence, and a slightly weaker T3 subapical band of tomentum match the
holotype
of
L. albuquerquense
and are here considered
L. stictaspis
s. str
..
Lasioglossum stictaspis
s. lat.
ranges south throughout
Mexico
and west to
California
. It can have almost any combination of punctation and surface sculpture in any location.
It is likely that
L. stictaspis
s. lat.
comprises multiple species, but correlates between morphological, genetic, and geographic variation cannot be found to support a species hypothesis. One of these may be
L. paululum
, but additional species from
Mexico
, Arizona, or
California
are likely undescribed. More data is needed to clarify limits and relationships between these species.