Anti-predator defence drives parallel morphological evolution in flea beetles

Abstract

Complex morphological or functional traits are frequently considered evolutionarily unique and hence useful for taxonomic classification. Flea beetles (Alticinae) are characterized by an extraordinary jumping apparatus in the usually greatly expanded femur of their hind legs that separates them from the related Galerucinae. Here, we examine the evolution of this trait using phylogenetic analysis and a time-calibrated tree from mitochondrial (rrnL and cox1) and nuclear (small subunits and large subunits) genes, as well as morphometrics of femora using elliptic Fourier analysis. The phylogeny strongly supports multiple independent origins of the metafemoral spring and therefore rejects the monophyly of Alticinae, as defined by this trait. Geometric outline analysis of femora shows the great plasticity of this structure and its correlation with the type and diversity of the metafemoral springs. The recognition of convergence in jumping apparatus now resolves the long-standing difficulties of Galerucinae -Alticinae classification, and cautions against the value of trait complexity as a measure of taxonomic significance. The lineage also shows accelerated species diversification rates relative to other leaf beetles, which may be promoted by the same ecological factors that also favour the repeated evolution of jumping as an anti-predation mechanism.

Predator-induced macroevolutionary trends in Mesozoic crinoids

“…However, our data, as well as those for several other groups (13,37,38), indicate that such interactions can have consequences, directly or indirectly, at higher taxonomic levels. Most compelling are cases of increasing incidence of taxa with well-developed antipredatory defenses, and it has been suggested that taxa possessing such traits may be more prone to speciation (38).…”

“…However, our data, as well as those for several other groups (13,37,38), indicate that such interactions can have consequences, directly or indirectly, at higher taxonomic levels. Most compelling are cases of increasing incidence of taxa with well-developed antipredatory defenses, and it has been suggested that taxa possessing such traits may be more prone to speciation (38). Although our study does not allow us to make any claims about whether differences in speciation and/or extinction rates are the cause of changes in diversities of motile and sessile crinoids, it does show that over geologic time diversities of well-defended taxa need not change in a monotonic fashion and may be correlated with diversities of predators.…”

Seasonal pattern of Chrysomelidae (Coleoptera) in the state of Paraná, southern Brazil

“…Predation can act to determine the seasonal pattern of the species, and Chrysomelidae display a wide range of predator avoidance behaviors. Among the groups mainly collected in this study (Galerucinae-Alticini and Eumolpinae) two important strategies are found: both have many species root feeders in larval stages and free leaf eaters as adults, and Alticini has another effective behavior, the ability to jump (Ge et al 2011). Besides, since herbivores have similar ecological requirements, interspecific competition is a major cause of community structure (Schluter & Ricklefs 1993) and Linzmeier & Ribeiro-Costa (2008) found that the Alticini (Chrysomelidae) of Ponta Grossa was structured in the seasons with food competition being the most likely cause.…”

The Alticini (Coleoptera: Chrysomelidae: Galerucinae) fauna ofDavraz Mountain (Isparta): comments on host plant and altitude preferenceswith two new records for Turkish fauna

“…Although it was treated as a separate subfamily in previous works and recent modern studies actively continue discussing Chrysomelidae phylogeny (Gomez-Zurita et al, 2007;Ge et al, 2011Ge et al, , 2012, the group is mostly classified as a tribe within the subfamily Galerucinae, and we follow this hypothesis in the present work. However, molecular data are still insufficient and need some further in-depth analyses due to the large number of unsampled genera.…”