Butll. Inst. Cat. Hist. Nat., 71: 83-95. 2003 ISSN: 1133-6889 GEA, FLORA ET FAUNA The life cycle of Andricus hispanicus (Hartig, 1856) n. stat., a sibling species of A. kollari (Hartig, 1843) (Hymenoptera: Cynipidae) Juli Pujade-Villar*, Roger Folliot** & David Bellido* Rebut: 28.07.03 Acceptat: 01.12.03 Abstract and so we consider A. mayeti and A. niger to be junior synonyms of A. hispanicus. Finally, possible causes of the speciation of A. kollari and The marble gallwasp, Andricus kollari, common A. hispanicus are discussed. and widespread in the Western Palaeartic, is known for the conspicuous globular galls caused by the asexual generations on the buds of several KEY WORDS: Cynipidae, Andricus, A. kollari, A. oak species. The sexual form known hitherto, hispanicus, biological cycle, sibling species, formerly named Andricus circulans, makes small sexual form, speciation, distribution, morphology, gregarious galls on the buds of Turkey oak, A. mayeti, A. burgundus. Quercus cerris; this oak, however, is absent from the Iberian Peninsula, where on the other hand the cork oak, Q. suber, is present. Recent genetic studies show the presence of two different Resum populations or races with distribution patterns si- milar to those of Q. cerris and Q. suber. We present new biological and morphological Cicle biològic d’Andricus hispanicus (Hartig, evidence supporting the presence of a sibling 1856) una espècie bessona d’A. kollari (Hartig, species of A. kollari in the western part of its 1843) (Hymenoptera: Cynipidae) range (the Iberian Peninsula, southern France and North Africa), Andricus hispanicus n. stat.. Biological and morphological differences separating these Andricus kollari és una espècie molt comuna dis- two species from other closely related ones are tribuida a l’oest del paleartic coneguda per la given and the new sexual form is described for the gal·la globular i relativament gran de la generació first time. This form of A. hispanicus, causing assexual que es localitza als borrons de diverses isolated bud galls in Q. suber, is identical to espècies de roure. La forma sexual coneguda fins Andricus mayeti n. syn. and Andricus niger n. syn. avui, denominada Andricus circulans, provoca petites gal·les gregaries als borrons del roure turc Quercus cerris, (aquest roure no es troba a la pe- * Universitat de Barcelona. Facultat de Biologia. Departament nínsula Ibèrica, on si que hi ha Q. suber). Recents de Biologia Animal. Avda Diagonal 645. E-08028 Barcelona, estudis genètics mostren la presència de dues Spain. E-mail: [email protected] ** Université de Rennes 1. Faculté Sciences. C.N.R.S. poblacions o races diferents amb un patró de UPRES- A 6026. Équipe Canaux Récepteurs Membranaires. distribució similar al de Quercus cerris i al de Q. Bât 13-Campus de Baulieu. 35042-Rennes Cedex - France. suber. En aquest estudi presentem evidències bio- 83 GEA, FLORA ET FAUNA lògiques i morfològiques que posen de manifest la forma es idéntica a Andricus mayeti (= Andricus presència d’una espècie bessona d’Andricus kolla- niger syn. n.), así pues consideramos Andricus ri en la zona oest d’Europa (península Ibèrica, sud mayeti como nueva sinonimia de Andricus de França i nord d’Àfrica), Andricus hispanica hispanica. Para finalizar, se discuten las razones status n. Es descriuen les diferències biològiques i que pudieron ocasionar la separación específica morfològiques que permetran separar aquestes entre Andricus kollari y A. hispanica. dues espècies d’altres espècies molt properes, i es descriu per primer cop la forma sexuada d’Andri- PALABRAS CLAVE: Cynipidae, Andricus, A. kollari, cus hispanica que ocasiona gal·les aïllades als A. hispanicus, ciclo biológico, especies geme- borrons de Quercus suber. Aquesta forma és idèntica a Andricus mayeti (= Andricus niger syn. las, forma sexual, especiación, distribución, n.), així doncs considerem Andricus mayeti com a morfologia, A. mayeti, A. burgundus. nova sinonimia d’Andricus hispanica. Per acabar, es discuteixen les raons que van poder ocasionar la separació específica d’Andricus kollari i A. Introduction hispanica. MOTS CLAU: Cynipidae, Andricus, A. kollari, A. The marble gall wasp, Andricus kollari, is hispanicus, cicle biològic, espècies bessones, one of the best known cynipids and has forma sexual, especiació, distribució, morfolo- received great attention in the literature gia, A. mayeti, A. burgundus. because of its interesting and complex life cycle and conspicuous unisexual galls. In former times these galls were collected for Resumen industrial purposes for their high tannin content. The dry substance can consist of up to 65 % Ciclo biológico de Andricus hispanicus tannins, and this substance was used for (Hartig, 1856) una especie gemela de A. tanning leather or producing ink (Kieffer, kollari (Hartig, 1843) (Hymenoptera: Cyni- 1897-1901). The native range of the species is pidae) divided geographically between south- western Europe (mostly the Iberian Penin- Andricus kollari, es una especie muy común dis- sula) and eastern Europe, although human tribuida en el oeste del paleártico, conocida por la introduction of the host of the sexual gene- agalla globular y relativamente grande de la gene- ración asexual producida en yemas de varias espe- ration, Quercus cerris (Turkey oak), has cies de roble. La forma sexual conocida hasta hoy, favoured its dispersal over northern and denominada Andricus circulans, provoca peque- north-western Europe (Schönrogge et al., ñas agallas gregarias en yemas del roble turco 1998), where it is now one of the most easily Quercus cerris, (este roble no se encuentra en la Península Ibérica, donde si hay Q. suber). Recien- found species at many sites. tes estudios genéticos mostraron la presencia de Beijerinck (1902) described the life cycle dos poblaciones o razas distintas con un patrón de of this species, and later Marsden-Jones distribución similar al de Quercus cerris y al de Q. (1953) and Folliot (1964) confirmed it. There suber. En este estudio presentamos evidencias biológicas y morfológicas que ponen de manifies- is a conspicuous unisexual generation forming to la presencia de una especie gemela de Andricus spherical monolocular bud galls (10-30 mm kollari en la zona oeste de Europa (Península Ibé- in diameter) on various species of Quercus rica, parte sur de Francia y Norte de África), Andricus hispanica status n. Se describen estas dife- subgenus Quercus while the bisexual gene- rencias biológicas y morfológicas que permitirán ration forms small gregarious galls in buds of separar estas dos especies de otras especies muy Q. cerris. Some authors have proposed that A. cercanas, y se describe por primera vez la forma kollari might reproduce without a sexual sexual de Andricus hispanica, que ocasiona aga- llas aisladas en las yemas de Quercus suber. Esta generation in its lifecycle in regions where Q. 84 cerris is either rare (such as the Transcar- doubt of the A. kollari type, and the adults pathian region of the Ukraine: Melika & obtained confirmed this observation. This ex- Csóka, 1993; Csóka, 1997) or entirely absent periment has been mentioned previously in (Iberia: Nieves-Aldrey, 1987; Csóka et al., Pujade-Villar (1992) and showed that although 1998; Dajoz, 1999). Pujade-Villar (1992) Q. cerris is absent from the Iberian Peninsula, reported the presence of a sexual generation the so-called Iberian A. kollari have an alter- in Iberian populations, although it was not nating life cycle in this area. As mentioned in described because only the sexual female was Pujade-Villar (1991), this sexual form is found. slightly different from the sexual form of Recent genetic results using allozyme data eastern A. kollari (formerly called A. circu- (Stone et al., 2001) support the presence of a lans); the relationship between the agamic sexual generation in Iberian populations and form (A. kollari) and the sexual form (A. suggest a genetic isolation between the circulans) was established by experimental eastern and western populations. According studies by Benson (1953). The two specimens to the results the eastern and western forms of from Montseny mentioned above were compa- A. kollari would have differentiated completely red with: a) adults emerged from sexual galls between 1 and 2 million years ago and have to found on Q. suber attributed to A. mayeti; b) a series of adults reared from them, because of be considered separate species. The western their high similarity; c) sexual galls of eastern form is found in the Iberian Peninsula, A. kollari obtained experimentally by R.F. in extending into south-west France, while the the north of France. Finally it was also eastern form occurs in eastern Europe, compared with other sexual forms of the including the Italian and Balkan peninsulas, kollari group (see Folliot et al., 2003). as well as in north and north-western Europe. Biological experiments with both Spanish It is very interesting that the distribution of and Northern French populations were also this western form shows a close coincidence carried out over several years. A large number with the distribution of Q. suber (cork oak), of unisexual galls collected in Spain and an oak closely related to Q. cerris. supposedly linked to Q. suber were brought The present study describes the discovery to France, where unisexual females were of the sexual male of the Iberian form and the reared for experiments on Q. cerris (R.F.), identification of the host of the sexual while northern French unisexual galls were generation as Q. suber, so that the redescrip- taken to Spain, where experiments on Q. tion of the western form of A. kollari as a new suber were performed (J. P.-V.). species can now be made. We follow the current terminology of morphological structures (Gibson, 1985; Ronquist & Nordlander, 1989), surface sculp- Material and methods turing is given after Harris (1978). Measu- rements and abbreviations used here include: Two sexual females of Andricus were POD (post-ocellar distance) is the distance found ovipositing in buds of Q.