Kokkocynips difficilis Nieves-Aldrey & Nicholls & Tang & Melika & Stone & Pujade-Villar & Buffington & Maldonado & Medianero 2021, n. comb.
Creators: name: Nieves-Aldrey, José Luis
name: Nicholls, James A.
name: Tang, Chang-Ti
name: Melika, George
name: Stone, Graham N.
name: Pujade-Villar, Juli
name: Buffington, Matthew
name: Maldonado, Yurixi
name: Medianero, Enrique
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Cynipidae
Kokkocynips
Kokkocynips difficilis

description: Kokkocynips difficilis (Ashmead, 1887) n. comb. (Figs. 9, 10E, 11E)
Andricus difficilis Ashmead, 1887. in: Tr. Amer. Ent. Soc, V. 14 p. 143.
Callirhytis difficilis (Ashm.): Mayr, 1902. Verh. Ges. Wien, v. 52, 289.
Material examined: syntype. Jacksonville, Fla. Collection Ashmead. Type No. 2878, USNM, Andricus difficilis Ashm., USNMENT 00802031 (USNM).
Other material examined: USA. Florida. Jacksonville. Coll. Ashm. 2 females, USNMENT00892936 and USN-MENT 01525988 (USNM). Texas. Hoxie. IX.6/1918. LH Weld, ex Q. phellos, 7 females, USNMENT01525989-USNMENT01525994, USNMENT01525999.
Gall: small (12 X 15 mm), irregularly rounded, densely rugose, reddish when young and turns grayish following gall maturation, slightly flattened at sides, the rugosities arranged transversally in five to six rows. These galls occur in clusters, emerging in rows from fissures or slits in the terminal twigs (Fig. 11E); when mature fall to the ground (Ashmead 1887).
Host plant: Quercus laurifolia, Q. cinerea, Q. catesbaei, Q. nigra, Q. myrtifolia and Q. phellos (Weld 1959).
Biology: only known from the asexual generation. According to Ashmead (1887), the adults emerge from galls from August to September; Weld (1959) noted that adults also emerged later in the year up to December.
Distribution: South-eastern North America, from Maryland southwards to Florida and westwards to Texas (Burks 1979, pers. obs.).
Remarks: in the original description the following set of morphological characters was mentioned: “Thorax almost smooth shining, with distinct parapsidal grooves, a median groove, the mesopleura showing fine, short microscopical striae; scutellum rugose not pubescent; abdomen microscopically punctate; wings hyaline, areolet distinct cubital cell almost closed”; our examination of specimens confirms this set of characters. Additionally we observed that the spine of the hypopygium is long (almost 6 times as long as wide in lateral view), without long subapical setae and the antennae is 14 segmented; F1 about 1.4 times as long as F2 (Figs. 9H, 10E).
Both the finely coriaceous to smooth and shiny mesoscutum and the absence of striae radiating from the clypeus indicate that C. difficilis is very different from Palaearctic species of Callirhytis (the true Callirhytis), all of which have a transversely ridged mesoscutum and conspicuous facial radiating striae (Nieves-Aldrey 1992). Recently two new genera, Zapatella Pujade-Villar & Melika, 2012 and Melikaiella Pujade-Villar, 2014, were described to include some Nearctic and Neotropical species of Callirhytis that did not fit the diagnostic characters of Palaearctic Callirhytis sensu Förster (Pujade-Villar et al. 2012a; Pujade-Villar et al. 2014). However, C. difficilis differs from these two genera as well. It differs from Zapatella by the absence of a ring of dense white setae on the second metasomal tergite, R 1 of forewing complete and relatively shorter ventral projection of the hypopygium (that is about 6 – 12 times as long as wide in Zapatella). This species does not possess either of the diagnostic characters of Melikaiella, namely the presence of areolate-reticulate sculpture on metasomal tergites (punctate in C. difficilis) and rugose sculpture of mesoscutum (finely and shiny coriaceous in C. difficilis).
The morphology suggests that this species falls into the clade of closely related species discussed in this study. The molecular results highlight the close relationship of this species to both K. imbricariae and K. doctorrosae (Fig.1, Table 1). Hence based on the morphological and molecular evidence the species is here transferred from Callirhytis to Kokkocynips.
description: Published as part of Nieves-Aldrey, José Luis, Nicholls, James A., Tang, Chang-Ti, Melika, George, Stone, Graham N., Pujade-Villar, Juli, Buffington, Matthew, Maldonado, Yurixi & Medianero, Enrique, 2021, Re-description and systematic re-appraisal of the genus Kokkocynips Pujade-Villar & Melika, (Hymenoptera: Cynipidae: Cynipini), including new combinations of Nearctic species and the description of a new species from Panama, pp. 205-232 in Zootaxa 4938 (2) on pages 224-226, DOI: 10.11646/zootaxa.4938.2.3, http://zenodo.org/record/4563818