Trophic diversity among the Blattodea

Traditional knowledge about the trophic behavior of cockroaches is based on lab studies of a few species that are common pests. However, ecological studies and field observations show that roaches are much more selective in their diet when conditions permit. Carnivory, herbivory, detritivory, omnivory, coprophagy and xylophagy are all behaviors which exist in the Blattodea and other behaviors, such as nectivory, are also hypothesized. The phylogenetic breadth of this diversity in feeding is quite unclear as the trophic habits of most species have not been described. By dissecting and examining the digestive contents of cockroaches collected in the tropical rainforests of Guyana, we wish to gain more insight on their selection of food items. One question in particular that remains unanswered relates to the feeding habits of bromeliad dwelling cockroaches. Preliminary data suggests that plant detrital food items in bromeliad ecosystems may be of low quality. This may affect cockroaches specialized to these ecosystems in terms of: their digestive structure, and their choice of food items. Our major objectives in this study are to determine:

a.       the diversity of feeding habits of cockroaches of Guyana as determined by gut contents

b.      the feeding habits in different groups of bromeliad dwelling cockroaches

c.       significant correlations between digestive structure (e.g. proventriculus and mouth parts) and feeding habits