Morphology of a new blister beetle (Coleoptera, Meloidae) larval type challenges the evolutionary trends of phoresy-related characters in the genus Meloe

Abstract

The discovery of some specimens of a new first instar larval type in\ud blister beetles, collected in Iran on Anthophora bees, confirms the\ud existence of repetitive and parallel trends in morphological specialization\ud to phoresy in distinct lineages of Meloidae and in particular in the\ud subfamily Meloinae. The new Iranian larva, herein described and illustrated,\ud shows several characters and a peculiar phoretic strategy that\ud closely parallel that of the Meloe subgenus Lampromeloe, with similar\ud modifications of the fronto-clypeal setae into strong lanceolate spines\ud used to pierce the intersegmental membranes of the bees. Both parallel\ud and shared derived evolution of these characters seem possible.The coexistence in this larva of characters in both primitive and\ud derived state is of particular interest in order to analyse the different\ud rates and trends of evolution of phoretic adaptations. A morphological\ud comparison (SEM) of this new meloine larva (incertae sedis), tentatively\ud assignable to Meloe, with the M. (Lampromeloe) larvae is carried\ud out in order to discuss the evolutionary implications of its placement\ud in Lampromeloe, and the relative characters that would support it, vs\ud other possible alternative scenarios

Phylogeny of Meloini blister beetles (Coleoptera, Meloidae) and patterns of island colonization in the Western Palaearctic

“…It also changes the phylogenetic placement of some taxa. Consequently, some previous hypotheses on character evolution and homoplasy in the group need to be reinterpreted, particularly those regarding the morphological traits of first‐instar larvae, which have been widely used to support or reject evolutionary groups within Meloini (Bologna, 1988, 1991; Bologna et al., 1989, 1990; Bologna & Pinto, 2001; Di Giulio et al., 2002, 2013, 2014; Pinto & Bologna, 1993; Selander, 1989).…”

Phoresy in animals: review and synthesis of a common but understudied mode of dispersal

“…1), suggesting multiple independent origins. Studies of specific taxa, including blister beetles (Bologna & Pinto, 2001; Bologna et al ., 2008; Di Giulio et al ., 2014) and acarid mites (OConnor & Pfaffenberger, 1987), show evidence for its repeated origins within multiple clades. For the behaviour to evolve independently multiple times, the benefits must sometimes outweigh the risks.…”

A new systematic arrangement for the blister beetle genus Eurymeloe (Meloini, Meloidae, Coleoptera) with the description of a new species from Spain

“…Larva. The morphological traits of previously known first instar larvae of Eurymeloe (triungulines), including Coelomeloe , and the descriptions of the triungulines of several additional species of Eurymeloe , have been synthesised and studied by Di Giulio et al (2013 , 2014 ). We herein refer to these works for larval morphological traits.…”

“…Morphological traits of larvae have been traditionally considered relevant in the systematics of the group, sometimes even more informative than adult characters for phylogenetic studies ( Bologna and Pinto 2001 ). In fact, traits of the first instar larva (triungulin) have been studied for most of the genera and subgenera of Meloini ( Bologna 1988 , 1991 ; Selander 1989 ; Bologna et al 1989 , 1990 ; Bologna and Pinto 1992 , 1998 ; Pinto and Bologna 1993 ; Bologna and Aloisi 1994 ; Di Giulio et al 2002 ; Di Giulio et al 2013 , 2014 ). However, not having a resolved internal taxonomy for Eurymeloe confuses explanations of the evolutionary history of some of these traits.…”