Parallel evolution in courtship songs of North American and European green lacewings (Neuroptera: Chrysopidae) CHARLES S. HENRY 1 *, STEPHEN J. BROOKS 2 , PETER DUELLI 3 , JAMES B. JOHNSON 4 , MARTA M. WELLS 5 and ATSUSHI MOCHIZUKI 6 1 Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT 06269, USA 2 Department of Entomology, The Natural History Museum, London SW7 5BD, UK 3 Swiss Federal Research Institute WSL, CH-8903 Birmensdorf, Switzerland 4 Division of Entomology, University of Idaho, Moscow, ID 83844, USA 5 Ecology and Evolutionary Biology, Yale University, New Haven, CT06520, USA 6 National Institute for Agro-Environmental Sciences, Tsukuba City, Ibaraki 305 8604, Japan Received 19 September 2011; revised 2 November 2011; accepted for publication 2 November 2011 Green lacewings of the Chrysoperla carnea species group use substrate-borne vibrational duetting songs rather than morphology or pheromones for species recognition. Because each of the many cryptic, reproductively isolated song species typically has an extensive geographic range, potentially interfertile biological species are broadly sympatric, and therefore must use distinct regions of acoustic song space if they are to remain reproductively isolated. However, this constraint does not apply to species restricted to different continents, giving rise to the possibility of parallel evolution of song phenotypes between continents. Here we describe a striking example of parallel song evolution, between a known European species, Chrysoperla pallida, and a newly discovered vivid-green North American species, Chrysoperla calocedrii sp. nov. To verify this parallelism, we show that: (1) the songs of the two species have measurably similar multi-volley temporal and frequency structure; (ii) the songs share the same basic genetic pathway; (iii) each species is unable to discriminate between its own and the other’s song in playback trials, confirming the acoustic niche overlap; (iv) the two species readily establish normal duets with each other in the lab, leading to copulation and the production of vigorous hybrid progeny bearing an intermediate song phenotype; (v) they have distinct morphologies in both adults and larvae, suggesting different adaptive responses and therefore independent evolutionary histories; and (vi) they occupy relatively distant positions in a Bayesian phylogenetic analysis of 4630 bp of protein-coding mitochondrial DNA, rejecting the alternative hypothesis of similarity through recent common ancestry. We include a formal description of C. calo- cedrii sp. nov. as a new species, and provide additional observations of its behaviour, ecology, and life history. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 776–796. ADDITIONAL KEYWORDS: acoustic space – Chrysoperla – convergent evolution – cryptic species – molecular phylogeny – reproductive isolation – species recognition. INTRODUCTION The globally distributed carnea group of the green lacewing genus Chrysoperla Steinmann, 1964 is a confusing assemblage of cryptic species. Within puta- tive species, for example, patterns of morphological and ecological variation are often contradictory and inconsistent when examined across broad geographi- cal areas. To make sense of these patterns, careful consideration of behavioural and genetic characteris- tics must be given, in addition to morphological and ecological traits. We now know that members of the carnea group sort themselves into reproductively iso- lated units, using species-specific substrate-borne *Corresponding author. E-mail: charles.henry@uconn.edu Biological Journal of the Linnean Society, 2012, 105, 776–796. With 9 figures © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 776–796 776 Downloaded from https://academic.oup.com/biolinnean/article-abstract/105/4/776/2452457 by guest on 27 July 2018