We believe the family Chrysomelidae (“leaf beetles”) is a veritable gold mine in this respect in that it is composed of taxa (subfamilies and tribes) with uneven levels of species diversity and wildly contrasting patterns of maternal investment and offspring feeding behavior. Ultimately, all Chrysomelidae are dependent upon plants, both gymnosperms and angiosperms, and within the latter, both monocots and dicots. We seek to integrate both botanical and entomological data to better understand the radiations of tropical leaf beetles, how their diversity has been affected by host plant traits and the role of innovations in larval trophic habits and defensive measures. Employing the comparative method to approach these questions requires assembling a robust phylogeny and gathering of life history information for a surprisingly large number of incompletely studied and described tropical beetle species.

Depending on which tribe of Cassidinae one is considering, trophic habits may be constrained or expansive. For example, those Cassidinae species which feed on exposed, second-growth vegetation tend to be associated with a small number (five to eight) of host plant families of dicotyledenous plants (morning glories, borages, asters, etc). The same is also approximately true for species feeding cryptically in semi-concealed habitats on undergrowth and forest vegetation including mainly monocotyledenous plants (gingers, palms, etc). Interesting and inexplicably, the diets of internally feeding, leaf-mining species differ in that they appear to have colonized a much broader sample of available host plant families, both Monocotylenonae and Dicotyledonae. We now ask whether these patterns are due to differences in the ages of the respective groups or are due to other factors governing the expansion of feeding habits.

Rice (Oryza sativa) was presumably introduced to Panama and other parts of the Americas from Africa and Asia centuries ago. Not until recently, however, have we taken note that this important exotic plant has become a favorite host of one species of cassidine beetle. Indigenous and other subsistence farmers growing rice in the eastern Province of Darien lose a considerable fraction of their crops to Oediopalpa guerini, a small, shiny blue-bodied beetle known to occur on other native and introduced grasses. Unlike the eggs of other Cassidinae in Panama, they are everywhere attacked by minute wasps in the family Trichogrammatidae, a group of parasitoids widely used across the world in biocontrol. In this particular case, however, our observations indicate the tendency of the ovipositing beetle to stack eggs one upon another limits the loss of eggs to a maximum of 40-50% and hence poses a limit on how successful biocontrol efforts might be. As a result, other means of naturally controlling this beetle in Panama must be investigated.

Beetles in the family Orsodacnidae are potent herbivores on many species of cycads in the Americas. Adults emerge at the beginning of each rainy season and proceed to inflict high levels of leaf damage over a very short period of time. These beetles are particularly enigmatic in that they do not fit easily into existing leaf beetle families and hence are relegated to their own species-poor family with uncertain evolutionary relationships to other families. Beetle fossils taken from Jurassic sediments of Kazakhstan and China suggest to some that the family may date back largely unchanged to the early and mid Mesozoic, a time when early gymnosperms and cycads were abundant and diverse. The complete life cycle of Neotropical Orsodacnidae remains an enduring mystery. We study this group to know whether their relationship with cycads is more intricate than a brief but intense period of herbivory would indicate.