New species of Dryocosmus Giraud gallwasps from California (Hymenoptera: Cynipidae: Cynipini) galling Chrysolepis Hjelmq. (Fagaceae)
Author
Nicholls, James A.
Author
Melika, George
Author
Stone, Graham N.
text
Zootaxa
2018
2018-12-19
4532
3
407
433
journal article
27741
10.11646/zootaxa.4532.3.6
6f171b80-465d-4b71-b931-c0c18c9e244d
1175-5326
2615473
96CB3686-4EDC-4B32-A06F-B859E868B7AF
Dryocosmus juliae
Melika, Nicholls & Stone
,
new species
Figs 18–45
urn:lsid:zoobank.org:act:
ED99B013-BB32-4FC4-8206-DFEC87B5F377
Type material.
HOLOTYPE
female: “
USA
,
CA
,
30 km
E of
Arcata
(
CA1232
), ex buds of
Chrysolepis chrysophylla
, leg.
J. Nicholls
, 2009.07.13”;
10 female
and
4 male
paratypes
:
3 females
and
1 male
with the same labels as the
holotype
;
1 female
“
USA
,
CA
,
30 km
E of Arcata
(
CA1253
), ex leaves of
Chrysolepis chrysophylla
, leg.
J. Nicholls
, 2009.07.13”;
1 male
as “
USA
,
CA
,
30 km
E of Arcata
(
CA1214
), ex leaves of
Chrysolepis chrysophylla
, leg.
J. Nicholls
, 2009.07.13”;
3 females
and
2 males
as “
USA
,
California
,
30 km
E of Arcata
, leg.
J. Nicholls
, 2012.07.0 1 ex leaves of
Chrysolepis chrysophylla
(
CA1313
, spCAl13_5)”;
1 female
as “
USA
,
California
,
30 km
E of Arcata
, leg.
J. Nicholls
, 2009.07.26 ex leaves of
Chrysolepis chrysophylla
(
CA1243
, spCAl14_2)”;
1 female
as “
USA
,
California
,
30 km
E of Arcata
, leg.
J. Nicholls
, 2012.07.23, adult emerge 2012.08.0 4, ex stems of
Chrysolepis chrysophylla
(
CA1310
, spCAs5_9)”;
1 female
as “
USA
,
California
,
30 km
E of Arcata
, leg.
J. Nicholls
, 2012.08.0 7 ex stems of
Chrysolepis chrysophylla
(
CA1312
, spCAs5_15)”
.
Holotype
female,
2 female
and
1 male
paratypes
are deposited in the
USNM
,
8 female
and
3 male
paratypes
in the
PHMB
.
Etymology
. Named in honour of Mrs. Julia DeMartini, wife of Prof. J. DeMartini, who provided extensive assistance looking for galls on
Chrysolepis
and other oak taxa.
Diagnosis.
Most closely resembles sexual
D. rileypokei
.
In
D. rileypokei
the malar space, in both females and males, has striae radiating from clypeus and reaching eye margin (
Figs 46, 50
), females are reddish brown, the occiput with numerous delicate striae (
Figs 48, 52
); the mesoscutellum delicately coriaceous (
Figs 60, 64
), lateral propodeal carinae subparallel (
Fig. 61
) while in
D. juliae
,
new species
, striae on the malar space are indistinct, short and not reaching the eye (
Figs 18, 22
), females are blackish, the occiput without striae (
Figs 20, 24
); the mesoscutellum uniformly rugose (
Fig. 30
), lateral propodeal carinae bent outwards at mid height (
Fig. 31
). The two species induce very different galls (
Figs 36–45
,
80–85
). Also resembles
D. demartinii
, see the key and the Diagnosis to
D. demartinii
.
Description.
Sexual female. Head dark brown to black; mandibles, labial and maxillar palps light brown; antenna brown; mesosoma and metasoma dark brown to black; legs uniformly yellow.
Head alutaceous, with sparse white setae, denser on lower face and occiput, 2.1x broader than long in dorsal view; 1.3x broader than high in anterior view and not broader than mesosoma. Gena alutaceous, not broadened behind eye, 2.4x narrower than cross diameter of eye, invisible in anterior view. Malar space alutaceous, with delicate, hardly traceable striae radiating from clypeus and not reaching eye; height of eye 3.0x longer than length of malar space. Compound eyes converging ventrally. POL 1.8x longer than OOL; OOL 1.6x longer than diameter of lateral ocellus, slightly longer than LOL; ocelli ovate, all equal in size. Transfacial distance 1.2x longer than height of eye and 1.55x longer than height of lower face (distance between antennal rim and ventral margin of clypeus); diameter of antennal torulus 1.2x longer than distance between them, distance between torulus and eye margin 1.4x longer than diameter of torulus. Lower face alutaceous, without striae, with elevated median area. Clypeus rectangular, flat, broader than high, alutaceous, with deep anterior tentorial pits, distinct epistomal sulcus and clypeo-pleurostomal line; ventrally rounded, not incised medially. Frons, interocellar area, vertex, occiput uniformly alutaceous. Postgena smooth, glabrous, postocciput around occipital foramen impressed, smooth, glabrous, with parallel striae; posterior tentorial pits large, deep, elongate; postgenal bridge narrow, 2.3x higher than broad; occipital foramen higher than height of postgenal bridge. Antenna with 12 flagellomeres, longer than head+mesosoma; pedicel 1.8x longer than broad, F1 2.0x shorter than length of scape+pedicel, equal in length to F2, F2 slightly longer than F3, F3 slightly longer than F4, F5 longer than F6, subsequent flagellomeres equal in length, F11 shorter than F12; placodeal sensilla on F3–F12, in numerous rows.
Mesosoma longer than high in lateral view. Pronotum smooth, glabrous; with few white setae and with irregular delicate wrinkles laterally, emarginate along lateral edge. Mesoscutum smooth, glabrous; nearly as long as broad (width measured across base of tegulae); notauli complete, deeply impressed for full length; median mesoscutal line in the form of a short triangle; anterior parallel and parapsidal lines not impressed, but traceable; parascutal carina broad, deep, anteriorly reaching notauli. Transscutal articulation deep, distinct. Mesoscutellum only slightly longer than broad, nearly rectangular, anteriorly slightly narrower than posteriorly; shorter than mesoscutum, uniformly rugose, overhanging metanotum; scutellar foveae transverse ovate, with smooth, glabrous bottom, divided by central elevated carina. Mesopleuron, including speculum, smooth, glabrous, with few white setae in ventroposterior third, without wrinkles at mid height; mesopleural triangle coriaceous, with few white setae and some delicate irregular short wrinkles. Metapleural sulcus reaching mesopleuron at half its height; preaxilla delicately coriaceous, glabrous; dorsal and lateral axillar areas glabrous, smooth, with few setae; axillar carina broad, with longitudinal striae; subaxillular bar narrow, smooth, glabrous, at most posterior end shorter than height of metanotal trough. Metascutellum uniformly coriaceous, higher than height of smooth, glabrous ventral impressed area; metanotal trough smooth, glabrous, with few white setae. Lateral propodeal carinae distinct, bent outwards at mid height, central propodeal area smooth, glabrous, without wrinkles; lateral propodeal area smooth, with dense white setae; nucha short, with delicate longitudinal sulci dorsolaterally and laterally.
Forewing as long or slightly longer than body, with distinct brown veins, margin with long dense cilia; radial cell 3.3x longer than broad, R1 and Rs nearly reaching wing margin; areolet triangular, well-delimited by distinct veins; Rs+M well-pigmented, its projection reaching basalis at mid-height. Tarsal claws simple, without basal lobe.
Metasoma longer than head+mesosoma, longer than high in lateral view, smooth, glabrous; 2nd metasomal tergite basally with ring of dense white setae only laterally, interrupted dorsally; 2nd tergite extending to 1/3 length of metasoma; prominent part of ventral spine of hypopygium nearly 2.5x longer than broad in ventral view, with white setae, extending beyond apex of spine but never forming a tuft. Body length
2.2–2.5 mm
(n=8).
MALE. The colour pattern of the body the same as in female. Similar to female but compound eyes bigger and thus frons and lower face narrower than in female; also ocelli bigger. Antenna longer than body, with 13 flagellomeres, F1 uniformly broad, curved and excavated. Body length
2.1–2.4 mm
(n=6).
Morphological variability.
In some
type
specimens (collection codes CA1313, spCAl13_5) the mesosoma is slightly lighter than in all others, otherwise no other differences were found.
Gall
(
Figs 36–43
) The sexual generation of
Dryocosmus juliae
,
new species
has four different galltypes, collected from
Chrysolepis chrysophylla
and
C. sempervirens
, and here listed under the field codes assigned to our collections. All galltypes occur at the same time (and often on the same individual plant) and probably reflect variation in the exact oviposition site within dormant buds before the buds develop into new growth/leaves with concurrent gall formation.
spCAl13 (
Figs 36–37
)—an integral leaf gall, typically developing in July, about
6–7 mm
in diameter, protruding mainly from lower surface of the leaf, sitting totally within the lamina of the leaf, never on the leaf edge, with a free-rolling inner larval cell. This is an undescribed galltype listed by
Weld (1957)
.
spCAl14 (
Fig. 38
)—an integral leaf gall, developing in July, about
3–4 mm
long and
2 mm
across, on the edge of the leaf blade, causing infolding of the lamina (sometimes all the way to the midrib), with a free-rolling inner larval cell. Very similar to the previous galltype (spCAl13); however, located on the edge of the leaf blade.
FIGURES 18–27.
Dryocosmus juliae
,
new species
. 18–21, head, sexual female: 18, anterior view, 19, dorsal view, 20, posterior view, 21, lateral view. 22–24, head, male: 22, anterior view, 23, dorsal view, 24, posterior view. 25–26, antenna: 25, sexual female, 26, male. 27, forewing, part, sexual female.
FIGURES 28–35.
Dryocosmus juliae
,
new species
. 28–34, sexual female: 28, mesosoma, lateral view, 29, mesoscutum, dorsal view, 30, mesoscutellum, dorsal view, 31, metascutellum and propodeum, posterodorsal view, 32–34, metasoma: 32, general lateral view, 33, part, lateral view, 34, part, ventral view. 35, male, metasoma, lateral view.
spCAb5 (
Figs 39–41
)—a small green gall that appears to be induced in terminal or axillary buds, conical, slightly pointed, up to
8 mm
long,
4–5 mm
diameter, with a free-rolling inner larval cell. Further investigation has shown that this gall is actually induced on a leaf, and the apparent position on a bud is because gall development stops leaf growth. Collected primarily in June and July, although some galls (one containing a viable pupa) were collected in October, perhaps indicating some proportion of larvae undergo a period of diapause.
spCAs5 (
Figs 42–43
)—an integral stem gall, collected in July and August, causing swelling of the terminal bud and immediately adjacent new twig growth.
The
asexual generation
of this species induces catkin galls, which were collected from
Chrysolepis sempervirens
at the two sites near Manzanita Lake (
USA
,
California
) on 2008.09.11 and 2012.09.24. However, at the time galls were collected only small larvae were inside the galls and no adults were subsequently reared. DNA sequences from these larvae matched those obtained from the sexual generation described above, confirming that this catkin gall is the alternate asexual generation of
D. juliae
,
new species
. These asexual generation galls (galltype code spCAc4) develop on staminate catkins, are around
4 mm
in diameter, with a fluffy buff coloured surface. The internal structure shows an inner larval cell located at the bottom of the gall with a "dummy" cell above that contains a small opening on the upper surface (
Figs 44–45
).
Biology.
Alternate sexual and asexual generations are known, developing on
Chrysolepis sempervirens
and
C. chrysophylla
. Galls of the sexual generation typically develop in June-August, adults emerge during the same period. Asexual galls on catkins starting to develop in September, adults probably emerge next spring.
Distribution.
USA
,
California
.