Comparative morphology, biology and phylogeny of terminal-instar larvae of the European species of Toryminae (Hym., Chalcidoidea, Torymidae) parasitoids of gall wasps (Hym. Cynipidae) JOSÉ F. GÓMEZ*, JOSÉ LUIS NIEVES-ALDREY and MARÍA HERNÁNDEZ NIEVES Dpto. de Biodiversidad y Biologia Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), Madrid, Spain Received 11 April 2007; accepted for publication 9 October 2007 We present a phylogenetic and taxonomic study of the morphology and biology of the terminal-instar larval stage of 19 species representing all the genera of Torymidae parasitoids of gall wasps in Europe, with the single exception of Megastigmus. The genera studied include Adontomerus Nikol’skaya, Idiomacromerus Crawford, Chalcimerus Steffan & Andriescu, Glyphomerus Förster, Pseudotorymus Masi and Torymus Dalman. We primarily used chaetotaxy and some head structures. The terminal-instar larvae of all studied species are thoroughly described for the first time and illustrated with SEM images. We provide diagnostic characters for the family and the genera studied, and keys to genera and species for the identification of torymid larvae associated with cynipid galls. The majority of the torymid larvae studied are solitary monophagous parasitoids. Finally, to assess the potential use of larval characters in systematic studies of the family, a phylogenetic analysis of the studied taxa based on 42 larval morphological characters is proposed and compared with the current taxonomy of Torymidae. Our results suggest that body chaetotaxy, and characters of the head and mouthparts could be used for genera and species discrimination. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154, 676–721. ADDITIONAL KEYWORDS: cynipid galls – food webs – identification key – immature stages. INTRODUCTION The family Torymidae is a cosmopolitan group of hymenopteran Chalcidoidea, comprising about 986 species in 68 genera, usually divided into two sub- families, Toryminae (55 genera and 808 species) and Megastigminae (12 genera and 174 species) in addition to a fossil genus with four species (Noyes, 1978, 1990, 2003; Bouc ˇek, 1988; Goulet & Huber, 1993; Grissell, 1995). Torymids display diverse larval feeding behaviour. Most species are parasitoids in cynipid and cecidomyiid galls, or attack various Diptera, Hymenoptera, Lepidoptera and Coleoptera, while some species are parasitoids of mantis eggs (Insecta, Dictyoptera). However, a significant number of species, particularly in Megastigminae, are phytophagous, living as inquilines in galls or feeding in the seeds of Rosaceae, Pinaceae and Cupressaceae (Bouc ˇek, 1988; Goulet & Huber, 1993; Grissell, 1995). About 335 species of Torymidae are recorded for Europe, of which 34 species, belonging to seven genera, are parasitoids in cynipid galls (Askew, Gómez & Nieves-Aldrey, 2004; Schönrogge, Stone & Crawley, 1995, 1996a, b; Nieves- Aldrey, 2001; Askew et al., 2006; Gómez et al., 2006; Hayward & Stone, 2006; R. R. Askew et al., unpubl. data). Thirteen species of torymid parasitoids of gall wasps have been recorded from oak cynipid galls (tribe Cynipini), while the remaining 21 species have been reared from cynipid galls on herbs and bushes (Tribes Aylacini and Diplolepidini) (Nieves-Aldrey & Askew, 2002; Askew et al., 2004, 2006). The family Torymidae was first described by Walker (1833) comprising the genera Megastigmus Dalman, *Corresponding author. E-mail: jgomez@mncn.csic.es Zoological Journal of the Linnean Society, 2008, 154, 676–721. With 22 figures © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154, 676–721 676 Downloaded from https://academic.oup.com/zoolinnean/article-abstract/154/4/676/2674297 by guest on 28 May 2020