UC Berkeley

The Aderidae (Coleoptera: Tenebrionoidea), commonly known as the puppet beetles or ant-like leaf beetles, is a moderately diverse beetle family with approximately 1,000 described species. Most species are small in size (1–4mm) and little is known regarding their natural history though adults are generally active on the surfaces of foliage, often collected using beating and sweeping methods. The family is widely distributed biogeographically and many species exhibit secondary sexually dimorphic characters of their antennae and hind legs. The characterization and identification of tribes, subtribes, and genera of Aderidae from all biogeographic regions is incredibly difficult and previous authors have expressed the need for a worldwide revision of the higher classification for the group – the puppet beetles are one of the taxonomically and systematically poorest known families in all of Coleoptera. The primary goal of this study was to reconstruct the evolutionary history of the beetle family Aderidae worldwide and examine the evolution of sexually dimorphic characters using current phylogenetic methods while incorporating both morphological and molecular data.

First, the Aderidae of New Zealand were revised in order to understand intraspecific morphological character variation and examine the structural diversity of sexually dimorphic features within the genus Zenascus. Three new genera and six new species were described and keys to the genera and species of the region were presented. The phylogenetic relationships of species in the genus Zenascus were reconstructed using parsimony and a correlation between gland pore abundance of the hind legs and the degree of antennal modification of males was found. Intraspecific variation of morphological characters that were previously used in higher classification of the Aderidae indicated that these character systems may be evolutionarily labile and not very useful for higher-level aderid classification.

These intraspecific findings were then used to inform the following two studies, which examined the Aderidae at the generic level using molecular and morphological data respectively. The molecular study represented the first comprehensive phylogenetic analysis of the puppet beetles that used over 150 exemplars representing all four tribes and eight aderid subtribes. The resulting phylogenies were used to characterize and establish major clades within the family and provide a robust phylogenetic classification for the group. Nomenclature changes include parsing the family into two subfamilies, the Aderinae and Cnopinae, and further dividing the Aderinae into five highly supported clades, which are designated as tribes (Aderini, Gompeliini, Euglenini, Phytobaenini, and Syzetonini). Ancestral state reconstructions for morphological characters that have been previously used to establish taxonomic relationships were evaluated within this phylogenetic context. The character of elytral pubescence was found to be phylogenetically informative for several clades whereas the degree of posterior cephalic constriction did not support major groupings. Metafemoral modifications provided phylogenetic signal at the generic level. Additionally, character mapping of sexually dimorphic characters was performed to investigate the evolutionary pathways of these character systems and determine whether dimorphism has arisen through character state gain in males, character state loss in females, or both. Sexual dimorphism of the hind legs appears to have a single evolutionary origin within the Aderidae, with an ancestral state of sexual dimorphism for the Syzetonini clade. Secondary loss of this dimorphism has occurred twice and resulted from both loss of the trait in males leading to monomorphism without ornamentation, and gain of the trait in females leading to monomorphism with ornamentation in both sexes.

Finally, the world genera of Aderidae were reviewed and redescribed and an identification key provided for all extant, adult genera. This study summarized the currently known taxonomic information, clearly defined the morphological limits of each aderid genus, and reassigned previously described species into established genera to enable future taxonomic work. Scanning electron micrographs for all main body regions were provided for the majority of genera in order to enable future character and state recognition and specimen identification. Three genera were newly described while twelve genus-level synonymies were established for the family. Additionally, a total of 362 generic reassignments were established based on type material examined.

The current natural history knowledge for aderid species is extremely limited, so in order to disentangle the ecological, behavioral, and biogeographical processes that underlie the macroevolutionary patterns presented here, additional life history and alpha-level taxonomic studies are required. The phylogenetic framework provided within these works will serve as a backbone for these future studies and will hopefully ignite additional research on the puppet beetles.