A key to the Mymaridae (Hymenoptera) egg parasitoids of proconiine sharpshooters (Hemiptera: Cicadellidae) in the Nearctic region, with description of two new species of Gonatocerus
Author
Triapitsyn, Serguei V.
text
Zootaxa
2006
1203
1
38
journal article
50803
10.5281/zenodo.172335
076b5447-7740-4af0-aef5-e34d9724424f
11755326
172335
Gonatocerus ashmeadi
Girault, 1915
(
Figs 21–25
)
Gonatocerus dolichocerus
var.
ashmeadi
Girault 1915
: 8
.
Gonatocerus ashmeadi
Girault
: Girault 1929: 25;
Huber 1988
: 53
–55 (subsequent references,
lectotype
designation, redescription, diagnosis, distribution, host associations);
Triapitsyn and Phillips 1996
: 10
; Triapitsyn
et al.
1998: 241–242 (distribution, host associations);
Triapitsyn, Bezark and Morgan 2002
: 38
–39 (distribution, host associations);
Vickerman
et al.
2004
: 338
–344 (biological, morphological, and molecular distinction between populations; distribution); de
León 2004a
: 314
–317 (molecular distinction between populations);
Hoddle and Triapitsyn 2004b
: 342
–343 (distribution, host associations); de León and Jones 2005: 1–7 (molecular distinction between populations); Triapitsyn
et al.
2006: 60–62 (illustrations, comparison with
G. u a t
S. Triapitsyn).
Type
locality
An unspecified locality in Texas,
USA
.
Material examined
EASTER
ISLAND
(
CHILE
). RanoKau,
1.iii.2006
, M. Beeche C. (ex. eggs of
H. coagulata
) [
3 females
,
1 male
,
UCRC
]. HAWAIIAN ISLANDS (
USA
, HAWAII). Oahu Island, Keehi Lagoon,
3.xii.2004
, R. Bautista (ex. eggs of
H. coagulata
on African tulip) [
1 female
,
3 males
,
CNCI
].
MEXICO
. TAMAULIPAS, Universidad Autónoma de Tamaulipas campus,
25.iii.2005
(emerged
1.iv.
2005
in UCR quarantine), S.V. Triapitsyn (ex. egg mass of
Oncometopia
sp. on hibiscus leaf) [
1 female
,
UCRC
].
USA
. CALIFORNIA: Riverside Co., Riverside, UCR campus,
23.vii.1996
, M. Grebus (ex.
Homalodisca
sp. eggs) [
5 females
,
5 males
,
UCRC
]. Ventura Co., Fillmore:
12.vii.2000
, R. Fenton (ex.
H. coagulata
eggs on lemon leaves) [
11 females
,
4 males
,
UCRC
];
23.viii.2000
, R. Fenton (ex.
H. coagulata
eggs on lemon) [
1 female
,
1 male
,
UCRC
];
23.viii.2000
, R. Fenton (ex.
H. coagulata
eggs on Valencia orange) [
6 females
,
4 males
,
UCRC
]. FLORIDA: Jefferson Co., Monticello,
25.vii.2000
, S.V. Triapitsyn (emerged in UCR quarantine
2–4.viii.2000
from an egg mass of
H. coagulata
; adult glassywinged sharpshooters sleeved on crape myrtle
18.vii.2000
by R. López, then sleeve removed and host eggs exposed
21.vii.2000
) [
7 females
,
UCRC
].
GEORGIA
: Houston Co., near Centerville,
32°38’03.3’’N
,
83°43’06.4’’W
,
131 m
,
21.vi.2004
(emerged
22–30.vi.
2004
in UCR quarantine), S.V. Triapitsyn, T. Cottrell (ex. proconiine sharpshooter egg masses on grasses) [numerous females and males,
UCRC
]. Peach Co., Byron,
21–22.vi.2004
, S.V. Triapitsyn (emerged
24.vi–6.vii.2004
at UCR quarantine from eggs of
H. coagulata
and
O. orbona
on leaves of crape myrtle, magnolia, etc.) [numerous females and males,
UCRC
].
NORTH
CAROLINA, Carteret Co., Morehead City,
20–27.viii.2000
, M. Wuenschel [
3 females
,
UCRC
].
SOUTH
CAROLINA, Charleston Co., Charleston,
22–23.vi.2004
(emerged
25–29.vi.
2004
in UCR quarantine), S.V. Triapitsyn (ex.
H. coagulata
eggs on crape myrtle) [numerous females and males,
UCRC
].
FIGURES 21–24.
Gonatocerus ashmeadi
(female). 21. Pedicel and basal funicle segments. 22. Mesosomal sternum. 23. Propodeum. 24. Forewing.
Diagnosis
The main distinguishing features of this species are as follows (mostly after
Huber 1988
). Body length (female) 1280–1760. Head and mesosoma generally dark brown, legs and gaster mostly yellow with brown bands on gastral terga; gaster may be almost completely dark brown in some males. Longitudinal sensilla present on F2–F8 of the female antenna; F1 without sensilla (
Fig. 21
). Mesosomal sternum with a distinct, welldefined yellow streak between each fore and middle coxae (
Fig. 22
). Submedial carinae on the propodeum thick, distinct, reaching the dorsellum (
Fig. 23
). Forewing (
Fig. 24
) hyaline or at most with a faint uniform brown tinge; cubital row of microtrichia on forewing blade complete, extending to base of marginal vein. Habitus of the female is shown in
Fig. 25
.
Gonatocerus ashmeadi
is most closely related to
G. uat
S. Triapitsyn (Triapitsyn
et al.
2006)
, from which it can be distinguished using the characters indicated in the key. Among the unrelated North American species of
Gonatocerus
,
G. ashmeadi
can be quite easily confused with another common and superficially very similarly looking (especially the coloration) species,
G. dolichocerus
Ashmead
, which belongs to the
bucculentus
subgroup of the
ater
species group (
Huber 1988
). Besides the subspeciesgroup distinguishing features indicated in Huber’s (1988) key to the North American species of the
ater
species group of
Gonatocerus
, females of
G. dolichocerus
can be separated from those of
G. ashmeadi
by a relatively shorter F
1. I
myself accidentally misidentified several specimens of
G. dolichocerus
as
G. ashmeadi
(
Vickerman
et al.
2004
)
, with the following label data:
USA
: Louisiana, East Baton Rouge Parish, Baton Rouge,
2–4.iv.2002
, S.V. Triapitsyn [
3 females
, UCRC]; Missouri, St. Clair Co., Chapel View Prairie,
29.vi.1999
, M.W. Gates [
1 female
, UCRC].
Distribution
Mexico
(Nuevo León and Tamaulipas) and
USA
(California, Florida,
Georgia
, Louisiana, Mississippi, North Carolina, South Carolina, Texas); its occurrence in Alabama and southern Arkansas, although not documented, is also very likely. The southern and southeastern
USA
strains of
G. ashmeadi
were released in California against
H. coagulata
(Morgan
et al.
2002;
Pilkington
et al.
2005
). Selfintroduced into Oahu Island, Hawaii (
USA
), where
G. ashmeadi
provides a good control of
H. coagulata
; intentionally and successfully introduced into Tahiti, Society Islands,
French Polynesia
, for biological control against
H. coagulata
(Mark S. Hoddle, personal communication). Selfintroduced into Easter Island (
Chile
) (new record), probably from
French Polynesia
; specimens were sent to me for identification by Sandra Ide Mayorga (Santiago,
Chile
). Triapitsyn
et al.
(2006) provided label data for the specimens of
G. ashmeadi
from Honolulu, Oahu Island, Hawaii (
USA
) that were sequenced for the molecular comparison with the North American specimens of this species and also with
G. u a t
S. Triapitsyn.
FIGURE 25.
Gonatocerus ashmeadi
(female). Photo by Jack Kelly Clark, University of California.
Hosts
Cuerna costalis
(Fabricius)
,
Homalodisca coagulata
(Say)
,
H. liturata
Ball
,
Oncometopia clarior
(Walker)
,
O. orbona
(Fabricius)
, and
Oncometopia
sp. Biological traits of
G. ashmeadi
are well known (Irvin and Hoddle 2004; 2005a, b;
Velema
et al.
2005
).
Comments
It can be supposed that
G. ashmeadi
might not be native to California; rather, it probably had accidentally introduced itself into California from somewhere in southern or southeastern
USA
long ago (before the 1980s) and established there on eggs of
H. liturata
, the local proconiine sharpshooter. Following establishment of
H. coagulata
in southern and central California during the 1990s,
G. ashmeadi
simply switched back to its natural host, providing good control of the summer brood of the glassywinged sharpshooter. The molecular data reported by
Vickerman
et al.
(2004)
and de León and Jones (2005) may support such an assumption.