Submitted to: Animal Behavior Society Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 30, 2008
Publication Date: N/A
Technical Abstract: Mormon crickets form bands and walk over rangeland in the western United States seeking salt and protein. Radio-tracking adult members of a Mormon cricket band in a high Sonoran desert of Utah, we investigated a potential trade-off between immunocompetence and migratory velocity. We asked: does access to a protein relative to a carbohydrate diet reduce locomotor activity and enhance immune defense? From hemolymph samples, we assayed activities of phenoloxidase and lysozyme - essential enzymes for the generalized immune respose to invasion. We found that the generalized immune response and locomotor activity of the Mormon crickets were all significantly and positively associated with body mass. Although there was no effect of diet on locomotor activity in this study, we found almost immediate effects of diet on immune defense. Mormon crickets are rapidly regulating their phenoloxidase activity but not their lysozyme activity to match their protein diet. This suggests that migrating Mormon crickets are deficient in phenoloxidase as a result of their protein deficiency. They either are not deficient in lysozyme or unable to up-regulate their activity in the 6 h time span given here.