Pairing of sexual and asexual generations of Nearctic oak gallwasps, with new synonyms and new species names (Hymenoptera: Cynipidae, Cynipini)
Author
Nicholls, James A.
0000-0002-9325-563X
james.nicholls@csiro.au
Author
Melika, George
0000-0002-5204-6890
melikageorge@gmail.com
Author
Digweed, Scott C.
0000-0001-5947-193X
scott.digweed@gmail.com
Author
Stone, Graham N.
0000-0002-2737-696X
graham.stone@ed.ac.uk
text
Zootaxa
2022
2022-06-01
5145
1
1
79
http://zoobank.org/1f909f98-7d98-4930-93d8-dd55008d9c76
journal article
112242
10.11646/zootaxa.5145.1.1
72c2e0c4-02cc-4a97-8981-86a19d405de4
1175-5326
6601806
1F909F98-7D98-4930-93D8-DD55008D9C76
Melikaiella tumifica
(
Osten Sacken, 1865
)
, asexual generation
Figs 114–118
,
120
Synonyms:
Cynips tumifica
Osten Sacken (1865: 356)
, female, male, gall.
Andricus (Callirhytis) tumifica
combination by
Mayr (1881)
;
Andricus (Callirhytis) tumificus
corrected spelling by
Dalla Torre (1893)
;
Callirhytis tumifica
combination by
Dalla Torre & Kieffer (1910)
;
Melikaiella tumifica
combination by
Pujade-Villar
et al.
(2014)
.
Material examined:
15 asexual females labelled as “
Germany
,
Baden-Württemberg
,
Schwetzinger Hardt
,
10km
SW of Heidelberg
, ex acorns
on
Q. rubra
, coll.
R
.
Beiderbeck
,
2014.10.01
, emerge
2017.03.22
”. Three asexual females have been deposited at the
USNM
,
12 females
at the
PHDNRL
.
Diagnosis.
Three
Melikaiella
species
from eastern North America are known only from their asexual generations:
M. fructuosa
(Weld, 1922)
,
M. fructicola
(
Ashmead, 1896
)
, and
M. corrugis
(Bassett, 1881)
, all of which produce galls in acorns of red oaks (
Pujade-Villar
et al
. 2014
). In
M. fructuosa
the female antenna has 10 flagellomeres and is shorter than in
M. tumifica
, reaching at most the level of the tegulae.
Melikaiella tumifica
adults most closely resemble those of
M. fructicola
and
M. corrugis
.
However, in
M. fructicola
and
M. corrugis
the mesoscutum is uniformly dull rugose in between and on either side of the notauli, mesoscutellar foveae without subparallel distinct longitudinal rugae while in asexual females of
M. tumifica
the mesoscutum is dull rugose between the notauli and delicately reticulate on either side of the notauli, mesoscutellar foveae distinctly divided by a central elevated carina and the bottom of foveae has strong longitudinal rugae.
Description.
Asexual female (
Figs 114–118
). Head and antenna rusty brown, except dark brown to black frons and interocellar area, mouthparts light brown; mesoscutellum, metascutellum, propodeum dark brown to black, legs rusty brown, metasoma dark brown.
Head reticulate, with sparse white setae, transverse, 1.3× as broad as high and broader than mesosoma in frontal view, 2.5× as broad as long in dorsal view. Gena reticulate, broadened behind eye in frontal view, as broad as transverse diameter of eye in lateral view. Malar space with malar sulcus and multiple delicate parallel striae on both sides of sulcus, radiating from clypeus and reaching eye; eye 2.2× as high as height of malar space. Inner margins of eyes diverging slightly ventrally. POL 1.4× as long as OOL; OOL 2.7× as long as diameter of lateral ocellus and 1.8× as long as LOL; all ocelli rounded, of same size. Antennal toruli in the ventral half of head height. Transfacial distance 1.1× as long as height of eye; diameter of antennal torulus 1.2× as long as distance between them, distance between torulus and eye 1.7× as long as diameter of torulus. Lower face reticulate, with white setae, without striae; median area delicately coriaceous, slightly elevated. Clypeus quadrangular, slightly broader than high, smooth, glabrous, with dense long white setae, ventrally slightly emarginate, without median incision; anterior tentorial pit large, rounded, epistomal sulcus and clypeo-pleurostomal line broad, well impressed. Frons reticulate, area under central ocellus and interocellar area coriaceous. Vertex uniformly reticulate, occiput with delicate transverse parallel rugae; postocciput reticulate, glabrous; postgena reticulate, with white setae; posterior tentorial pit large, ovate, area below impressed; occipital foramen higher than height of postgenal bridge; hypostomal carina emarginate, continuing into postgenal sulci which diverge strongly toward occipital foramen, postgenal bridge anteriorly broader than high.Antenna shorter than head+ mesosoma, with 12 flagellomeres, pedicel slightly longer than broad, F1 2.2× as long as pedicel and 1.4x as long as F2, F2 slightly longer than F3, subsequent flagellomeres gradually shorter until F10, F11 2.2× as long as F10 (in some specimens a suture visible so antenna has 13 flagellomeres), placodeal sensilla on F5–F12.
Mesosoma slightly longer than high. Pronotum reticulate with uniformly distributed parallel rugae; propleuron smooth, glabrous. Mesoscutum uniformly rugose between notauli, reticulate on outer side of notaulus, without setae; slightly longer than broad (greatest width measured across mesoscutum level with base of tegulae). Notaulus complete, deep, broad; bottom smooth, glabrous, with transverse rugae; posteriorly slightly broader and slightly converging; anterior parallel line impressed in anterior 1/3 of mesoscutum length; median mesoscutal line in the form of a short impression; parapsidal line distinct, broad, delimited by smooth glabrous area, extending to 2/3 of mesoscutum length; circumscutellar carina broad, smooth, foveolate. Mesoscutellum elongated, slightly longer than broad, trapezoid, posteriorly rounded, uniformly dull rugose, overhanging metanotum. Mesoscutellar foveae separated by narrow elevated rugose central area, transversely ovate, 2.0× as broad as high; bottom smooth, glabrous, with strong longitudinal parallel rugae. Mesopleuron uniformly reticulate; mesopleural triangle rugose, with irregular striae; dorsal and lateral axillar areas reticulate, with a few white short setae; subaxillular bar smooth, glabrous, at posterior end as high as height of metanotal trough; metapleural sulcus reaching mesopleuron in upper 1/3 of its height, upper part of sulcus distinct. Metascutellum rugose, 3.0x as high as height of smooth, glabrous ventral impressed area; metanotal trough smooth, glabrous, with strong longitudinal parallel rugae; central propodeal area smooth, glabrous, with strong irregular rugae; lateral propodeal carinae strong, nearly parallel; lateral propodeal area smooth, glabrous, with strong irregular rugae. Nucha with strong sulci dorsally and laterally. Coxae reticulate, rest of legs smooth, glabrous; tarsal claws simple, without basal lobe.
Forewing longer than body, hyaline, margin without cilia, veins dark brown, radial cell open, 2.6× as long as broad; R1 and Rs reaching wing margin; areolet absent, Rs+M distinct along entire length, reaching basalis slightly above its mid height.
Metasoma longer than head+mesosoma, longer than high in lateral view; 2nd metasomal tergum extending to 1/3 length of metasoma in dorsal view, without setae anterolaterally, microreticulate in posterior 1/3; all subsequent terga microreticulate, glabrous. Prominent part of ventral spine of hypopygium slightly longer than broad in ventral view, narrowing towards apex, with short setae ventrally which do not extend beyond apex of spine. Body length
3.1–3.3 mm
(n = 5).
Gall.
Sexual generation gall (
Fig. 119
) is a large, multilocular thickening of the leaf midrib/petiole. Asexual galls (
Fig. 120
) are in acorns (
Beiderbeck & Nicholls 2014
). The acorns are stunted, smaller than a non-infected acorn, and contain up to 6–7 cryptic larval chambers; the cotyledons are brown or used up by the larvae (
Beiderbeck & Nicholls 2014
).
FIGURES 119–120.
Melikaiella tumifica
(Osten Sacken)
. 119, sexual gall. 120, asexual gall.
Biology.
See
Beiderbeck (2012)
,
Beiderbeck & Nicholls (2014)
, and
Pujade-Villar
et al.
(2014)
for the biology of this species. The sexual generation develops on
Q. rubra
and
Q. velutina
; the asexual only known so far from
Q. rubra
. Sexual generation leaf galls develop in early spring; adults emerge in May-June. Asexual acorn galls were found in October - November, maturing in November. Adults overwinter in galls and emerge in the following spring.
Distribution.
USA
:
New York
,
Virginia
,
North Carolina
,
Illinois
,
Iowa
(
Burks 1979
).Also an introduced species in
Germany
(Heidelberg) on introduced
Q. rubra
(
Beiderbeck 2012
,
Beiderbeck & Nicholls 2014
).
Molecular taxonomy.
Alternate
generations (using larvae of the asexual generation) were matched with sequence data by
Beiderbeck & Nicholls (2014)
; here we supplement those data with additional sequences from sexual and asexual adults.
In
total, nine individuals (four asexual females, two sexual females, three sexual males) were sequenced for cytb and seven individuals (four asexual females, two sexual females, one sexual male) were sequenced for ITS2; these individuals were sourced from an introduced population in
Germany
as well as a nativerange population in
North Carolina
, USA.
Cytb
sequences were on average 0.18% divergent (range 0–0.46%; GenBank accessions
MG
821060
,
MW
326694
,
OM
321634
–
OM
321640
)
;
ITS2 sequences were 0–0.20% divergent (
OM
331823
–
OM
331829
)
.
Comments.
The genus
Melikaiella
Pujade-Villar, 2014
(
Pujade-Villar
et al
. 2014
) is allied to “true”
Callirhytis
from the Western Palaearctic, or as previously called,
Callirhytis
‘sensu stricto’ (
Pujade-Villar
et al
. 2012a
). It thus makes good sense that their asexual generations develop in cryptic galls inside acorns, as is also the case for
Callirhytis
sensu stricto
.
Melikaiella
was described with three new species from
Mexico
:
M. amphibolensis
Pujade-Villar, 2014
,
M. bicolor
Pujade-Villar, 2014
and
M. reticulata
Pujade-Villar, 2014
; and one from the
USA
,
M. ostensackeni
Pujade-Villar, 2014
. The species
Callirhytis sonorae
Weld, 1944
from
Mexico
,
C. corrugis
,
C. flora
Weld, 1922
,
C. fructicola
,
C. fructuosa
,
C. lupana
Weld, 1944
and
C. tumifica
were also transferred to
Melikaiella
, and
Callirhytis petrosa
Weld, 1922
was synonymized to
Melikaiella corrugis
(
Pujade-Villar
et al
. 2014
)
. The species status of
Cynips papula
Bassett, 1881
from the
USA
, an earlier synonym of
Callirhytis quercusmodesta
(
Osten Sacken, 1861
)
, was restored and this species was also transferred to
Melikaiella
, under the new name combination
M. papula
(
Pujade-Villar
et al
. 2014
)
. Subsequently,
Medianero & Nieves-Aldrey (2014)
described the species
Callirhytis cameroni
from
Panama
, and although they mentioned that it most likely belonged to the genus
Melikaiella
,
it was not formally transferred. Thus, the number of species in this genus is currently 12.