New state and host records for Agromyzidae (Diptera) in the United States, with the description of thirty new species
Author
Eiseman, Charles S.
Author
Lonsdale, Owen
text
Zootaxa
2018
2018-09-14
4479
1
1
156
journal article
29197
10.11646/zootaxa.4479.1.1
73cc6f7d-b3ec-40c5-adc7-52b9e0cbf236
1175-5326
1452913
93C84828-6EEF-4758-BEA1-97EEEF115245
Agromyza soka
spec. nov.
(
Figs. 5–6
,
78
,
230–233
)
Holotype
.
USA
.
VIRGINIA
:
nr.
Plummers Isl.
,
20.v.1914
,
R.C. Shannon
(
1♂
,
USNM
).
Paratypes
.
USA
.
CONNECTICUT
:
Hartford Co.
,
East Hartford, Two
Rivers
Magnet Middle School,
4.vi.2016
, em
.
27–29.iv.2017
, C.S. Eiseman, ex
Robinia pseudoacacia
, #CSE3574, CNC939943–939946 (3♂ 1♀, CNC);
NORTH
CAROLINA
:
Scotland
Co.,
Laurinburg
,
St. Andrews University
,
24.iv.2015
, em
.
16–18.iii.2016
, T.S. Feldman, ex
Robinia pseudoacacia
, #CSE2248, CNC653954, CNC653955 (1♂ 1♀, CNC);
4.iv.2016
, em.
18.iv– 3.v.2017
, T.S. Feldman, ex
Wisteria floribunda
, #CSE3518, CNC939744–939747 (1♂ 3♀, CNC).
Etymology.
The specific epithet (Gr.
sokos
—“stout, strong”) refers to the complex, heavily-sclerotized phallus.
Hosts.
Fabaceae
:
Robinia pseudoacacia
L.,
Wisteria floribunda
(Willd.)
DC.
Leaf mine.
(
Fig. 78
)
A
broad, green track, contorted to form a secondary blotch that occupies most of the leaflet surface. Frass is in discrete, rather closely spaced, black grains.
Puparium.
(
Fig. 6
) Reddish-brown; formed outside the mine.
Distribution.
USA
: CT, NC, VA. We have found larvae producing similar leaf mines in MA, and these have also been reported from NY, PA, VA, and WV (see Comments).
Adult description.
Wing length
2.3–2.5mm
(
♂
), 2.3–3.0mm (
♀
). Length of ultimate section of vein CuA1 divided by penultimate section: 0.6–0.7. Eye height divided by gena height: 6.9–9.2. Ocellar triangle relatively small and rounded. First flagellomere small and nearly circular or slightly longer than high, with nearly indistinct apical tuft of pale hairs. Notum pruinose.
Chaetotaxy
: Two ors, two or three ori (anterior seta small if present). Ocellar and postvertical setae subequal to outer vertical seta. Five dorsocentrals, strongly decreasing in length anteriorly. Eight irregular rows of acrostichal setulae. Mid tibia with one (male
paratype
) or two posteromedial setae.
Coloration
: (
Fig. 5
) Setae dark brown with light brown reflection. Body predominantly dark brown (female darker) with light pruinosity; antenna dirty orange with distal half of first flagellomere infuscated (more so dorsally) in
holotype
, entirely brown in
paratypes
, with antenna entirely dark brown in female; frontal vitta, gena and postgena paler; apices of fore or all femora narrowly yellow; tarsi yellow; fore tibia light brown, fading to yellow at base. Calypter white with hairs brown. Haltere white.
Genitalia
: (
Figs. 230–233
) Surstylus not distinct from epandrium, barely visible laterally, flat on inner surface and with four large spines. Cerci narrow and convergent. Hypandrium broad with thick arch, small apical process, and large inner lobe with two distal setae and several minute basal pits. Postgonite lobate and downturned. Proepiphallus and metepiphallus strongly reduced, flattened. Phallophorus elongate on left side. Halves of basiphallus strongly diverging from, and partially fused to phallophorus; lateromedially with lightly sclerotized membranous lobe; apex folded inwards, with pointed basal process and elongate distal process that is fused to mesophallus. Hypophallus broad, flat and heavily sclerotized; apically split in dissected NC male. Mesophallus cylindrical, dark, basally rounded, slightly longer than wide, fused to distiphallus. Distiphallus broad, black, ventrally tilted and cup-like with constricted opening enclosing haired inner process. Ejaculatory apodeme welldeveloped with blade paler, no medial rib evident.
Comments.
Reminiscent of those species related to
Agromyza bispinata
, the surstylus of
A
. soka
has few pronounced spines (
Fig. 231
) and there is a subcircular first flagellomere, but the flagellomere is not much longer than the pedicel and any longer hairs on the segment are restricted to an ill-defined apical tuft. Furthermore, the calypter has darker hairs, there are five dorsocentrals, the cercus is narrow, the epandrium is not darkly pigmented around the base of the spines, and the phallus is very dark and highly derived. Due to the variably colored antennae of this species, it will not readily key in
Spencer & Steyskal (1986)
, although most specimens will be identified as
A
. parca
, which has entirely dissimmilar male genitalia.
The leaf mines of this species (as “an unidentified dipterous leaf-miner (
Agromyzidae
)”) were described and illustrated by
Weaver & Dorsey (1967)
from material collected in West Virginia, but no adults were reared.
Valley (1982)
described
Phytoliriomyza robiniae
(Valley)
from adults caught on
Robinia pseudoacacia
in Harrisburg
, Pennsylvania between
22 and 30 April
of 1979, 1980, and 1981, attributing to this species the leaf mines studied by Weaver & Dorsey. Valley reported collecting the larvae in New York (
16–30 May
), Pennsylvania (
1–19 May
), Virginia (
26 April–10 May
), and West Virginia (
10 May
). The paratypes of
Agromyza soka
were collected in North Carolina on
24 April
; we have found larvae in Connecticut on
3 June
, and our photographs from
14 June
2013
in Massachusetts show mostly brown, abandoned mines, but one is still green and appears to contain a healthy larva. As stated by Valley, there is just one generation per year, with pupae overwintering. While there is strong circumstantial evidence associating
P. robiniae
with
R. pseudoacacia
, we are skeptical that the larvae are leafminers on this plant, and we consider the larval records presented by
Valley (1982)
to represent
A. soka
.
The undetermined
Agromyza
reared from
Robinia pseudoacacia
by
Scheffer & Lonsdale (2018)
in
New
York
is presumably also referable to this species. They also reported
Phytoliriomyza robiniae
from
New
York
, but based only on the leaf mine, “a pale green-yellow blotch that forms at the leaf margin midway between the leaf tip and base” (the
Agromyza
mine was described as a “darkish blotch encompassing much of the distal half of the leaf”). The leaf mines they illustrate for
P. robiniae
resemble those of
A
. soka
and were likely misidentified.