Larval morphology and biology of ...
�� The Norwegian Academy of Science and Letters ��� Zoologica Scripta, 34 , 1, January 2005, pp37���48 37 Marvaldi, A. E. (2005). Larval morphology and biology of oxycorynine weevils, and the higher phylogeny of Belidae (Coleoptera, Curculionoidea). ��� Zoologica Scripta, 34 , 37���48. Phylogenetic relationships among members of the family Belidae (Curculionoidea) were reconstructed through cladistic analysis using 58 characters and 17 terminals. The characters were from larval morphology (30), adult morphology (25) and biology regarding larval host- plants and feeding habits (three). They were scored for exemplar taxa in 17 genera, represent- ing different belid subfamilies and tribes, plus two outgroup taxa in Megalopodidae and Nemonychidae. The sampled genera included all those for which larval and adult information is available, and two known only from adults. New information on the larvae and biology of two oxycorynines is provided. These are the Chilean Oxycraspedus cribricollis , whose larvae live in decayed female strobili of the gymnosperm Araucaria araucana , and Hydnorobius hydnorae from Argentina, whose larvae, described and illustrated in the present paper, develop inside the flower and fruit bodies of Prosopanche americana (Hydnoraceae), a root-parasitic angiosperm. The relationships proposed by the single optimal cladogram resulting from simultaneous analysis of all taxa and characters are recovered by one of three optimal cladograms based on the larval data set alone. The cladogram justifies a revised classification of Belidae in two sister subfamilies: Belinae (with tribes Pachyurini, Agnesiotidini and Belini) and Oxycoryninae (with tribes Oxycorynini and Aglycyderini). It summarizes larval and adult synapomorphies defining the family Belidae, subfamilies and tribes. Based on the phylogenetic tree, the evolution of biological traits is traced. Larval development in vegetative organs of conifers is ancestral in Belidae. A shift to reproductive structures characterizes the Oxycorynini, a habit which was conserved while several shifts to distantly related host-plant groups occurred. Adriana E. Marvaldi, Instituto Argentino de Investigaciones de las Zonas Aridas (IADIZA), Consejo Nacional de Investigaciones Cient��ficas y T��cnicas, C. C. 507, 5500 Mendoza, Argentina. E-mail: email@example.com Blackwell Publishing, Ltd.
Larval morphology and biology of oxycorynine weevils and the higher phylogeny of Belidae (Coleoptera, Curculionoidea) A DRIANA E. M ARVALDI Accepted: 9 April 2004 Introduction The family Belidae is a monophyletic group of relatively basal weevils (Curculionoidea), according to evidence from morphology (of larvae and adults) and 18S rDNA sequences (Marvaldi et al . 2002). Kuschel (1995a) provided the first cladistic analysis supporting the monophyly of Belidae, and defined three, putatively monophyletic, constituent sub- families: Belinae, Aglycyderinae and Oxycoryninae. These have family rank in other classificatory schemes (i.e. Thompson 1992 Zimmerman 1994 see also Alonso-Zarazaga & Lyal 1999). The monophyly of each belid subfamily has not yet been tested. Nor has a phylogenetic study of relationships within each subfamily been considered, with the exception of Belinae (Kuschel & Leschen 2003). Their cladistic study on generic relationships of Belinae is based almost exclusively on adult morphology, with only eight larval characters scored for the eight genera for which larvae are known. Based on the results, the three recognized tribes of Belinae (Belini, Agne- siotidini and Pachyurini) are re-delimited and defined, but uncertainty remains because the Pachyurini appear to be paraphyletic with respect to a monophyletic Belini or (if some characters are weighted differently) to a monophyletic Agnesiotidini. As Kuschel & Leschen (2003) pointed out, additional larval characters scored for more terminals would be helpful to resolve these problems. The aims of the present paper are to: (1) explore the signific- ance of larval characters for recognizing natural groups and estimating phylogenetic relationships of the weevil family Belidae (2) clarify evolutionary aspects on shifts in larval habits and host-plant associations in this group of weevils. The monophyly and relationships of the major taxa (i.e. subfamilies and tribes) of Belidae are explored via cladistic analysis based on larval morphological evidence and via simultaneous analyses by adding data on adult anatomy, as well as biological data. In
Larvae and phylogeny of Belidae ��� A. E. Marvaldi 38 Zoologica Scripta, 34 , 1, January 2005, pp37���48 ��� �� The Norwegian Academy of Science and Letters this paper, the larval comparative morphology of Belidae is reviewed and expanded by adding new information, particu- larly for the subfamily Oxycoryninae, as larvae of species in two critical genera are now available. These are the larvae of the Chilean Oxycraspedus cribricollis , recently discovered living in female fallen strobili of the gymnosperm Araucaria araucana (Mol.) Koch (Marvaldi et al . 2003 in preparation), and the larvae of Hydnorobius hydnorae from Argentina, described and illustrated in the present paper, along with a summary on the biology of the species. Materials and methods Specimens examined Taxon sampling. For the phylogenetic analysis, characters were scored for species representing 15 belid genera (13 for which larval and adult information is available, and two known only from adults), plus two outgroup taxa. The placement in subfamilies and tribes of the sampled taxa, listed below, is according to Kuschel (1995a) and Kuschel & Leschen (2003) (see also Alonso-Zarazaga & Lyal 1999). The three belid subfamilies were represented in the sample, with more than one representative in different tribes, thus allowing the cladistic analysis to test monophyly and to indicate relationships among and within subfamilies. List of species examined. Larval material from Australia and New Zealand was borrowed from the New Zealand Arthropod Collection (NZAC) and corresponds to species studied by May (1993, 1994). The larvae of species from Argentina and Chile, together with adult voucher specimens, are held at the Instituto Argentino de Investigaciones de Zonas Aridas, Mendoza, Argentina (IADIZA). Adult specimens of two oxycorynines were borrowed from the Museo Argentino de Ciencias Naturales, Bernardino Rivadavia, Buenos Aires (MACN). Character states of some species were taken from the literature and references are given accordingly. Ingroup. Belinae, Pachyurini: Pachyurinus sticticus (Broun) [New Zealand (NZAC)] Rhicnobelus rubicundus (Broun) [New Zealand (NZAC)] Sphinctobelus niger Zimmerman [Australia (May 1994)] Hadrobelus undulatus (Zimmerman) [Australia (May 1994)]. Belinae, Agnesiotidini: Agathinus tridens (Fabricius) [New Zealand (NZAC)] Cyrotyphus blandus [Australia (NZAC)]. Belinae, Belini: Rhinotia spp. [Australia (May 1994)]. Aglycyderinae: Aralius wollastoni (Sharp) [New Zealand (NZAC)] Proterhinus spp. [Hawaii (Anderson 1941)]. Oxycoryninae, Oxycorynini: Oxycraspedus cribricollis (Blanchard) [Chile (IADIZA)] Hydnorobius hydnorae (Pascoe) [Argentina (IADIZA)] male and female adult speci- mens of Alloxycorynus bruchi (Heller) [Argentina (MACN)], and Oxycorynus missionis Kuschel [Argentina (MACN)]. Oxycoryninae, Allocorynini: Parallocorynus sp. [Mexico (May 1993)] Rhopalotria spp. [Central America (Emden 1938 May 1993)]. Outgroup. Chrysomeloidea, Megalopodidae, Palophaginae: Palophagoides vargasorum Kuschel [Argentina and Chile (IADIZA)]. Curculionoidea, Nemonychidae, Rhinorhynchinae: Rhynchitomacerinus kuscheli (Voss) [Argentina and Chile (IADIZA)]. Preparation, terminology and illustration of larvae. The tech- niques for preservation, dissection and slide mounting of larvae follow May (1993, 1994). Illustrations were made with camera lucida associated with stereo and compound micro- scopes. The terminology employed in larval descriptions generally follows May (1994) and is explained and illustrated in Marvaldi (1999). Phylogenetic analysis Characters and data matrix. A total of 58 characters (30 from larval morphology, 25 from adult morphology and three from larval feeding habits) were scored for exemplar taxa in 17 genera. The characters and states are described and listed in the Appendix. The data matrix is shown in Table 1. Cladistic analyses. Trees were reconstructed using the parsi- mony program NONA (Goloboff 1998). The search was per- formed through tree bisection reconnection (TBR) branch swapping on random addition replicates (commands hold* hold/100 mult*20 max*). The program WINCLADA (Nixon 2002) was used for visualizing character changes and to prepare the cladogram figure. Characters were equally weighted and treated as unordered (except character 24, additive). The support to tree topology was evaluated by means of bootstrap and jackknife values, using default commands in WINCLADA (via NONA ). The data matrix (Table 1) was analysed simul- taneously. The larval morphological data set (30 characters �� 15 taxa) was also analysed separately, to evaluate the contri- bution of this source of evidence to belid phylogeny. Then, an expanded data matrix of larval plus adult morphology (55 characters �� 15 taxa) was analysed, followed by the addition of biological data (58 characters �� 15 taxa), and finally the two terminals known only from adults were also included in the simultaneous analysis (58 characters �� 17 taxa). Results and discussion Phylogeny of Belidae The simultaneous analysis, including all characters and taxa, resulted in a single most parsimonious tree (Fig. 1) of 125 steps, consistency index (CI) = 0.68, and retention index (RI) = 0.81. The cladistic analysis of the larval morphological