Heidi Hopkins

Lecturer, Biology


Recent Presentation

“A species-rich genus of “desert” cockroaches and some factors contributing to species niche.” Resource Management and Biodiversity in Cockroach and Termite Lineages: Exploring the Common Ground in their Nutrition, Biodiversity and Systematics. International Conference of Entomologists.  Orlando, FL. September 2016.


Introduction:  A revision of the genus Arenivaga revealed 39 new species, raising to 48 the number of extant species.  Addition research analyzed the relative contributions of 23 ecological variables to the niche of the genus and species therein. This analysis revealed that more than 95% of their ecological niche is described by eight variables.

Methods:  The revisionary work is based on examination of more than 5200 adult male specimens on loan from 31 private and institutional collections. Maxent was used to understand the extent and details of the distribution of the genus. Nonparametric multidimensional scaling analysis was used to portray the impact of the examined ecological variables on individual species’ distributions.

Results:  Arenivaga is now the most speciose genus of native cockroach in the United States and it seems likely that there are more species to be found.

The exploratory analysis of the niche of Arenivaga revealed that of the 23 ecological variables examined, only eight contributed significantly. This analysis revealed that soil is the most important contributor, followed by precipitation of the driest month, and precipitation of the wettest quarter. Currently there is no evidence to support niche conservatism between closely related species, indicating that adapting to new and variable niches is one of the drivers of speciation in this genus.

Key Words: Blattodea, Corydiidae, Polyphagidae, Arenivaga, cockroach, desert, speciation, ecological niche models, niche conservatism, niche evolution, species boundaries, species distributions