Experimental study of the reproductive cycle of Plagiotrochus amenti Kieffer, 1901 (Hymenoptera, Cynipoidea, Cynipidae), with comments on its taxonomy

LUCAS GARBIN; NORMA B. DIAZ; JULI PUJADE-VILLAR

BOLETÍN de la ASOCIACIÓN ESPAÑOLA DE ENTOMOLOGÍA

Año: 2008 vol. 32 p. 341 - 349

Plagiotrochus amenti Kieffer, 1901 is a circum-Mediterranean gallwasp species introducedto the American continent together with its host, Quercus suber, centuries ago. In this work,asexual females obtained after their emergence from branches of Q. suber collected in anorth-eastern area of the Iberian Peninsula were released inside experimental tulle bags forovipositing. The alternating life cycle for autochthonous populations of P. amenti has beenestablished for the first time experimentally just recently, in contrary to the earlier knownpurely parthenogenetic populations introduced to America and known as P. suberi Weld,1926. In this study: (1) the historical knowledge of this species is shown, (2) the differentreproductive hypothesis are explained and the experimental results of the reproduction ofthe circum-Mediterranean populations are presented, and (3) the possibility of allopatricspeciation and the existence of different life cycles (only parthenogenetic and alternatingasexual and sexual generations) within this species in Europe are discussed.