The individuals that disperse, reach a crop first, and reproduce early in infestations are a non-random portion of the source population, but have a disproportionately large impact on the growth and genetic composition of the population. It is therefore crucial to understand what causes a small portion of the population to disperse and, for that small portion, evaluate the traits they possess that facilitate establishment. I aim to directly link individual insect behaviors to landscape scale dynamics. My objective is to investigate potential cues that influence dispersal, and the consequences of among-individual variation in dispersal for life history and reproductive traits in destination populations. My central hypothesis is that individuals vary in their sensitivity to resource competition as detected by vibrations of feeding larvae and individuals that disperse have genetically correlated traits that facilitate population expansion. Using the cowpea bean beetle (Callosobruchus maculatus), a pest that damages stored legume seeds, I will

 

1) Assess the extent to which larval feeding vibrations indicate competitor density and function as a cue for dispersal through recordings and playback experiments (click here for more information), and 

 

2) Determine traits that are genetically correlated with dispersal by comparing populations artificially selected for high and low dispersal propensity (click here for more information)

Cowpea Bean Beetle​

The bean beetle (Callosobruchus maculatus) is a classic species for studying metapopulation dynamics.  The beetle lives its entire life on legumes, such as black-eyed peas (Vigna unguiculata) and mung beans (Vigna radiata). Bean beetles are easy to maintain in the lab for multiple generations.  Adults live 1-2 weeks and do not require any food to survive.  Females lay eggs on beans, where the larvae will develop entirely inside the bean until they emerge as adults.

Funding Sources

Picture3.png
Picture3.png
Picture3.png
Picture2.png
Picture3.png