The roles of phylogeny and ecology in shaping Cassidine beetle associations with diverse tropical vegetation

Cassidinae (tortoise and leaf-mining beetles) exhibit highly specialized associations with grasses, palms, bamboo, Zingiberales, and diverse eudicotyledonous plants.  Recent phylogenetic analyses at the tribal and generic levels indicate that basal cassidines are mostly stem and leaf-miners, while the large clade of exophagous tortoise beetles feed on eudicot hosts.  In the transition zone between these two extremes are several tribes of cryptic exophagous scrapers that live in unopened leaves of various monocots.  My preliminary results from an elevational transect study in Peru indicate that these historical patterns influence the spatial distribution of cassidines in tropical habitats such that only certain species may be found in the forest canopy or in the under-story palms within a forest, but other clades are restricted to groves of bamboo and Zingiberales. Tree fall gaps and trails attract more sun-loving cassidines and can temporarily elevate species diversity for a forest habitat.  Both ecological and evolutionary behaviors must be considered in designing sampling protocols for accurate diversity assessment of Chrysomelidae.