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theses

Cockroaches are a moderately diverse but understudied insect order with the majority of their diversity present in the tropics. Recent works have made great strides in improving our understanding of the cockroach faunas of Brazil, Ecuador, Argentina, and Colombia. However, the subcontinent-sized landmass known as the Guiana Shield (itself containing three countries and parts of another two) has been largely ignored by cockroach systematists and taxonomists for over 20 years. The first goal of this dissertation research is to update the current understanding of the cockroach fauna in the Guiana Shield. Once this has been accomplished through synthesis of existing data and collection of new data from the field, we describe the diversity at multiple scales using perspectives that are more widely applicable to our understanding of ecology and systematics. This includes: exploring the relationship between dispersal ability and the evolution of geographic ranges (regional scale), the effect of species delimitation on estimates of species richness within a community of cockroaches (local/community scale), and the effect of specific landscape variables on species distributions (local/species scale). The major finding of this dissertation include: 3 descriptions of new species; 18 new species records including 1 genus entirely new to the Guiana Shield; the iii understanding that different approaches to identification can yield huge (~25%) discrepancy in estimated richness; that savannas limit the distributions of cockroach taxa but patterns of flooding do not; and that flight ability may affect how geographical ranges evolve, with better flying taxa having ranges more clustered in space. We also provide minor ethological and ecological insights from side projects or field observations.

ETD_7082

Ph.D.

Includes bibliographical references

by Dominic Anthony Evangelista

doi:10.7282/T3JM2CW7

ETD doctoral

The author owns the copyright to this work.