Kokkocynips difficilis ( Ashmead, 1887 ) Nieves-Aldrey & Nicholls & Tang & Melika & Stone & Pujade-Villar & Buffington & Maldonado & Medianero, 2021

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, Zootaxa 4938 (2), pp. 205-232 : 224-226

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 .

Figures

FIG. 9. Kokkocynips difficilis (Ashmead), n. comb., female, SEM pictures. (A) Head dorsal view. (B) Head anterior view. (C) Mesosoma dorsal view (D) Mesosoma lateral view. (E) Propodeum. (F) Metasoma lateral view. (G) Detail of mesoscutellar foveae. (H). Hypopygium.

FIG. 10. Female habitus of species of Kokkocynips. (A) Kokkocynips decidua (Beutenmueller) n. comb. (B) Kokkocynips doctorrosae Pujade-Villar. (C) Kokkocynips coxii (Bassett) n. comb. (D) Kokkocynips rileyi (Ashmead) n. comb. (E) Kokkocynips difficilis (Ashmead) n. comb. (F) Kokkocynips imbricariae (Ashmead) n. comb.

FIG. 11. Galls of species of Kokkocynips. (A) K. doctorrosae Pujade-Villar. (B) Kokkocynips imbricariae (Ashmead). (C) Kokkocynips coxii (Basset). (D) Kokkocynips decidua (Beutenmueller). (E) Kokkocynips difficilis (Ashmead). (F) Kokkocynips rileyi (Ashmead). (G) Kokkocynips attractans (Kinsey). (H) Kokkocynips panamensis n. sp.

FIG. 1. Majority-rule consensus tree of species sampled from across the Cynipini, based on a Bayesian analysis of a concatenation of three loci (cytochrome b, long-wavelength opsin, and the D2 region of the 28S rRNA gene). Black stars at nodes indicate ±95% posterior probability support; white stars indicate 70%-94% posterior probability support. The revised limits of the genus Kokkocynips are indicated by the grey shaded box.