Material and methods
Adult gallwasps were reared from galls collected on Quercus bumelioides Liebm. (= Quercus copeyensis C.H.Mull.) by Paul Hanson (details below).
We follow the current terminology for morphological structures in Liljeblad and Ronquist (1998) and Melika (2006). Abbreviations for fore wing venation follow Ronquist and Nordlander (1989), and cuticular surface terminology follows that of Harris (1979). Measurements and abbreviations used here include: F1-F15, 1st and subsequent flagellomeres; POL (post-ocellar distance) is the distance between the inner margins of the posterior ocelli; OOL (ocellar-ocular distance) is the distance from the outer edge of a posterior ocellus to the inner margin of the compound eye; LOL, the distance between lateral and frontal ocelli. The width of the forewing radial cell is measured from the margin of the wing to the Rs vein.
The SEM photographs were taken with a Stereoscan Leica-360 by Palmira Ros-Farré (Universitat de Barcelona) at a low voltage (700V) and without coating, in order to preserve the specimens. Pictures of the adult wasp habitus and wings were taken by a digital camera Canon PowerShot SX210 15 by Juli Pujade-Villar. Gall images were taken by Kenji Nishida. The images will be available from the “morphbank.com” databank.
The type material is deposited in the following institutions:
UB Universitat de Barcelona, Spain (J. Pujade-Villar);
PDL Pest Diagnostic Laboratory (the former Systematic Parasitoid Laboratory, SPL), Tanakajd, Hungary (G. Melika);
MZUCR Museo de Zoología, Universidad de Costa Rica (P. Hanson).
Hymenopteran parasitoids reared from the galls are deposited in MZUCR.
Discussion
It is essential to make a detailed examination of Coffeikokkos diagnostic characters and compare with morphologically similar Cynips L. complex-Atrusca Kinsey, Biorhiza Westwood (particularly with species previously placed in the now synonymized Sphaeroteras Ashmead) and Trigonaspis Hartig (particularly with species previously placed in the now synonymized Xanthoteras Ashmead) –because of one ambiguous character: the state of the tarsal claw. For the newly described genus, we mentioned that the tarsal claws possess a rounded basal lobe. However, this character can be interpreted in two ways: (i) the tarsal claw with a broad rounded basal lobe or (ii) the tarsal claw is simple, with a broad basal part of the claw. It is difficult to define exactly whether a basal lobe is present or the basal part of the claw is just broad (Fig. 4). In all other known Cynipini genera the basal lobe, when present, is acute and a distinct “tooth” is present, while in others the tarsal claw is narrow, without a lobe or (as Coffeikokkos) a broadened basal part.
Coffeikokkos differs from all known Cynipini genera by antennae that have 14–15 flagellomeres, instead of the usual 11–12. In the diagnosis, we mentioned that Coffeikokkos resembles Cynips and particularly Cynips korsakovi, a species known from Transcaucasus, Azerbaijan (Belizin 1961, Maisuradze 1962) and Iran (G. Melika, personal observation) (see Diagnosis to the genus Coffeikokkos above).
All asexual representatives of the entire Cynips complex (including synonymised Antron Kinsey and Besbicus Kinsey; Melika and Abrahamson 2002) have a ligulate, saddle-shaped, 2nd metasomal tergite, the height of the ventral impressed area of the metanotum always shorter that the height of the metascutellum, and the tarsal claws have an acute, distinct basal lobe. There are some species within this complex that resemble Coffeikokkos, but in known Antron species the mesoscutum is delicately coriaceous or microreticulate, never smooth, glabrous; in many species the prominent part of the ventral spine of the hypopygium is broadened at the apex, and all tergites are laterally densely setose. All Antron species are known to induce detachable, usually rounded, leaf galls; galls are never on twigs. Also the Antron species known to associate with only white oak species.
In Atrusca the antennae have 12 flagellomeres, the mesoscutum is coriaceous or microreticulate, the tarsal claws have an acute basal lobe, the radial cell of the forewing is very short, with Rs strongly curved toward the wing margin and the prominent part of the ventral spine of the hypopygium is very short and broadest at the apex, or long and narrowing toward the apex. The central propodeal area is like that in Coffeikokkos, but the lateral propodeal carinae are complete, reaching the nucha, and in the posterior half they are parallel, or only slightly curved outwards; the ventral impressed area is always shorter, sometimes much shorter, than the height of the metascutellum. There are some species of Atrusca, e.g., Atrusca clavuloides (Kinsey), with a smooth mesoscutum, dull rugose mesoscutellum and the same shape and form of the prominent part of the ventral spine of the hypopygium as in Coffeikokkos; however, the antennae have 12 flagellomeres, the mesoscutum is more densely setose, the fore wings have distinct dark spots, and the lateral propodeal carinae are complete, being only slightly curved outwards in the middle, and located much closer to one another. Another species, Atrusca pulchripennes (Ashmead), is also similar to Coffeikokkos in the polished mesoscutum, the shape of scutellar foveae, and the ventral impressed area of the pronotum is higher than the height of the metascutellum. However, in Atrusca pulchripenne, the lower face in anterior view is more transverse, the clypeus is broadly emarginate ventrally (much larger compared to the height of the lower face) and overhangs the mandibles, the radial cell in the forewing is short, with Rs strongly curved backward at the wing margin and the lateral propodeal carinae are complete and much closer to one another in the posterior half; the prominent part of the ventral spine of the hypopygium is needle-like, without a tuft of subapical setae. Moreover, all known species of Atrusca (like all asexual forms in the Cynips complex) induce galls exclusively on leaves of white oaks.
Coffeikokkos also partially resembles another Nearctic genus, the former Sphaeroteras (synonymised with Biorhiza by Melika and Abrahamson 2002), particularly Biorhiza rydbergiana (Cockerell), which has a smooth, sparsely setose mesoscutum along the notauli; it is also similar in the habitus of the mesoscutellum with scutellar foveae, the short, broad, parallel-sided ventral spine of the hypopygium, and the metasoma with sparse setae only on lateral parts of the 2nd metasomal tergite. However, in Biorhiza rydbergiana the antennae have 12 flagellomeres; the tarsal claw is simple, without a basal lobe; the ventral impressed area of the metanotum is much shorter than the height of the metascutellum; and the sides of the pronotum, mesopleuron, metascutellum and propodeum have more dense setae. The shape of the central propodeal area somewhat resembles that of Coffeikokkos in that the lateral propodeal carinae are parallel and curved outwards in the posterior part of the propodeum; however, they are complete, reaching the nucha, and are slightly less divergent in the posterior half. Galls of Biorhiza rydbergiana are induced on leaves.
Coffeikokkos also partially resembles yet another Nearctic genus, the former Xanthoteras Ashmead (some of the species were synonymised with Trigonaspis and others with Biorhiza (Melika and Abrahamson 2002)). Some of these species are similar to Coffeikokkos, but all have antennae with 12 flagellomeres, tarsal claws with an acute basal lobe, and the malar sulcus is present. In particular, the habitus of Biorhiza eburnea (Bassett) and Biorhiza polita (Bassett) somewhat resembles that of Coffeikokkos: the mesoscutum is polished, with rows of setae along the complete notauli, the mesoscutellum and scutellar foveae are similar in shape and surface sculpture, the shape of the 2nd metasomal tergite, with few lateral setae, is also similar. However, the tarsal claws have an acute basal lobe, the antennae have only 12 flagellomeres, the malar sulcus is present, the lateral propodeal carinae are slightly curved outwards posteriorly, and the ventral impressed area of the metanotum is shorter than the height of the metascutellum, the prominent part of the ventral spine of the hypopygium narrows toward the apex (it is thus more needle-like) and has few subapical setae reaching beyond the apex of the spine, not forming a tuft of setae. Both species of Biorhiza induce detachable, spherical leaf galls on white oaks.
There is one distinct feature of Coffeikokkos, on the basis of which it is easy to separate this newly described genus from all other known genera: the antennae have 14–15 flagellomeres, while in all other Cynipini only 11–12 are present. Moreover, the very peculiar galls resemble red coffee fruits.
The discovery of the new genus supports the idea about the American radiation centre of Cynipini (Kinsey 1936). Further research and collecting are necessary to decide whether Coffeikokkos is an evolutionary novelty distributed only in the Neotropics or the genus representatives are distributed also further northward, into the Nearctic region.