Cerroneuroterus Melika & Pujade-Villar, 2010

Melika, George, Pujade-Villar, Juli, Abe, Yoshihisa, Tang, Chang-Ti, Nicholls, James, Wachi, Nakatada, Ide, Tatsuya, Yang, Man-Miao, Pénzes, Zsolt, Csóka, György & Stone, Graham N., 2010, 2470, Zootaxa 2470, pp. 1-79 : 22-24

Cerroneuroterus Melika & Pujade-Villar , new genus

Figs 158–163, 164–168, 169–174, 175–177.

Type species: Neuroterus lanuginosus Giraud, 1859 . Designated herein.

Etymology. The name of the genus indicates the host association with the section Cerris of the genus Quercus , and the close morphological similarity to the genus Neuroterus .

Gender: Masculine.

Diagnosis. Similar to Neuroterus but the malar sulcus always absent; also resembles Pseudoneuroterus but the head trapezoid, not rounded in anterior view. More diagnostic characters are given in the generic key and the Description below.

Description In both asexual and sexual generations, malar sulcus always absent, tarsal claws simple, without basal lobe. Antennae of both sexual and asexual females, with 12 flagellomeres ( Figs 160, 172). In asexual females head transverse, distinctly broader than high in anterior view and slightly broader than mesosoma; genae fully or partially visible in anterior view; lower face and head posteriorly with dense white setae; transfacial distance 1.2 – 1.3 times longer than height of eye ( Figs 158, 169); notauli usually complete, well impressed along entire length, reaching pronotum; in some species (for example, C. folimargo ( Monzen, 1954)) notauli less impressed in anterior half, but always strongly impressed in posterior half ( Figs 161, 173); mesoscutellum posterolaterally emarginate and elevated above mesoscutellum; mesoscutum and mesoscutellum always entirely and uniformly smooth, shiny, mesoscutellum laterally and posteriorly emarginate, nearly as long as broad, broadest part in posterior half; scutellar foveae absent instead, anterior narrow transverse impression present, usually more impressed than disk of mesoscutellum ( Figs 161, 162, 173); projecting part of ventral spine of hypopygium never more than 2.0 times as long as broad in ventral view ( Figs 167 – 168, 176); 2nd metasomal tergite dorsally extending less than to half length of metasoma ( Figs 166, 176). In sexual females and males, head more rounded; notauli absent, indicated by rows of setae only but then female antennae always with 12 flagellomeres and in male antenna F1 strongly modified, expanded and flattened distally; usually equal or slightly shorter than F2.

Comments. Five Western Palaearctic species are transferred into the newly established genus: three species with the only sexual generation known: Cerroneuroterus aggregatus (Wachtl) , new comb., C. cerrifloralis (Müllner) , new comb., C. obtectus (Wachtl) , new comb. and two species with the only asexual generation known: C. lanuginosus (Giraud) , new comb. ( Fig. 179) and a closely related C. gyulaigaraiae (Melika) , new comb., recently described from Syria ( Melika 2006b). Further research will probably match alternate generations among these species ( Stone et al. 2009). This genus reflects Kinsey’s (1923) subgenus Neuroterus , except for the exclusion here of N. politus and P. saliens . Kinsey (1923) included in his Neuroterus subgenus three Eastern Palaearctic species, N. atamiensis , N. hakonensis , and N. nawai , all described by Ashmead (1904) from Japan, on the basis of adult wasps, without knowing the galls they induce. The taxonomic status of these Eastern Palaearctic taxa will be discussed elsewhere.

Cerroneuroterus minutulus (Giraud) , new comb. We also formally transfer to Cerroneuroterus an additional Western Palaearctic species, Neuroterus minutulus Giraud , on the basis of its host association with section Cerris oaks and the original description of asexual females. This species is cited in many regional faunas including Austria, Hungary, Italy ( Dalla Torre & Kieffer 1910; Ambrus 1974), Romania ( Ionescu 1973), Bulgaria ( Vassileva-Samnalieva 1984), and Ukraine (Transcarpathian region - Zerova, Diakontschuk & Ermolenko 1988; Melika 2006a). Only asexual females are known, which induce tiny (1 mm across when mature), unilocular, egg-shaped leaf galls on veins, predominantly on the lower side of the lamina. The type material of N. minutulus however has been lost (MNHN, Paris, C. Villemant, pers. comm.). In fact, regional faunas mentioning this species are based on galls and not on adult wasps. Galls described by Müllner (1901) (see also comments in Kieffer 1897 – 1901) and which he thought to be asexual generation galls of Dryocosmus mayri Müllner , could be identical with those attributed to N. minutulus (galls are deposited in the NHMW, Vienna; examined and discussed in Pujade et al. (2003)) and thus it is not out of the question that N. minutulus might be the asexual generation of Dryocosmus mayri . Very young or parasitised galls of other oak gallwasp species may be very similar in size and location. Thus we prefer the more conservative approach of treating this species as one with uncertain status until adults are obtained for detailed morphological analysis. However, formally we transfer it to Cerroneuroterus , and thus C. minutulus (Giraud) , new comb.

Below some Eastern Palaearctic Cerroneuroterus species are discussed.

Cerroneuroterus folimargo ( Monzen, 1954) , new comb. ( Fig. 181). The asexual generation was described by Monzen (1954). Yukawa & Masuda (1996) found the sexual generation experimentally, which induces tiny catkin galls (cf. Figs C – 097 and C – 086 in Yukawa & Masuda, 1996). Both generations develop on Q. acutissima . Genae, broadened behind the eyes, visible in anterior view; the female antenna with 12 flagellomeres and the posteriorly deeply impressed notauli assign this species to Cerroneuroterus . The asexual spangle gall of this species is located on the end of a vein or spine of the leaf, on the underside, pale pinkish, conical, 2 mm in diameter and very similar to the gall of C. vonkuenburgi (Dettmer) , but in C. folimargo , the gall is located always at the leaf edge, at the end of veins with only a single gall per leaf. The sexual generation is a tiny catkin gall, while in C. vonkuenburgi the sexual generation galls form woolly masses on catkins. The sexual generation galls are very similar to those of C. monzeni (Dettmer) as well as the asexual spangle galls, however, adults of the asexual generation differ from those of C. vonkuenburgi and C. monzeni (see the key to the asexual Cerroneuroterus species below). Asexual females emerge in April, overwintering in the gall and induce tiny catkin galls, adults of which emerge in late May. Associate with Q. acutissima and Q. variabilis , currently known only from Japan, also occurs in Taiwan.

Cerroneuroterus monzeni ( Dettmer, 1934) , new comb. ( Fig. 182). The sexual females, reared from catkin galls on Q. acutissima , were originally described by Dettmer (1934). Later, Monzen redescribed the sexual generation including males ( Monzen 1954). Yukawa & Masuda (1996) experimentally matched the sexual (photo C – 101) and the asexual (photo C – 092) generations. Galls of the sexual generation are on catkins of Q. acutissima , the galls are small, conical, yellowish, smooth, with few setae, thin walled, monolocular, 2mm in diameter. Small asexual spangle galls develop on the underside of leaves, similar in shape to those induced by the Western Palaearctic species N. numismalis, rounded and flattened with a central dimple, dark red, without fringe of hair around the gall ( Fig. 179). The asexual females overwinter in the galls, emerge in March-April, and induce catkin galls from which the adults emerge in May of the same year. Known on Q. acutissima and Q. variabilis only from Japan ( Dettmer 1934; Monzen 1954).

Cerroneuroterus vonkuenburgi ( Dettmer, 1934) , new comb. ( Figs 169 – 174, 175 – 177, 183). Neuroterus vonkuenburgi var. wakayamensis Monzen was recently synonymized to N. vonkuenburgi ( Abe et al. 2007) . Yukawa & Masuda (1996) experimentally showed that this species does have a sexual generation, galls of which form large woolly masses on catkins (pictures C – 088 and C – 090, asexual galls and C – 096 and C – 102, sexual galls). Both generations associate with Q. acutissima and Q. variabilis ; known from Japan ( Ashmead 1904; Dettmer 1934; Monzen 1954; Yukawa & Masuda 1996) and Taiwan (Taoyuan Co., Fuhsing Township; Hsinchu Co., Hsinfong Township and Jiashih Township; Taichung Co., Central Cross Island Road, Heping Township; Nantou Co., Cingjing Farm, Renai Township; all ex Quercus variabilis ) (authors). It is a new record for Taiwan. Galls appear on the tree from early August, develop through the summer and in early November, when they are mature, individually or together with leaves fall to the ground. Under the laboratory conditions, adults emerged from late November. In Hsinchu County, Hsinfong Township, adults were observed to lay eggs on leaf or flower buds of Q. variabilis from late January of 2010.

Comments. Neoneuroterus , a genus established by Monzen (1954), with two Japanese species, N. kashiyamai Monzen and N. bonehenrici (Dettmer) [the taxonomic position of which will be discussed elsewhere], was synonymized with Neuroterus ( Melika & Abrahamson 2002) . Kovalev (1965) described three other Neoneuroterus species from the Far East of Russia, N. nephroideus , N. spumeus , N. vernicosus . All three of these species possess a distinct transscutal articulation, and on the basis of the given character set and examined types (by GM), were transferred to Trigonaspis Hartig ( Melika & Abrahamson 2002; Abe et al. 2007).