Date of Award


Document Type

Union College Only

Degree Name

Bachelor of Science



First Advisor

Scott Kirkton




changes, grasshoppers, alter, body, delivery


In developing vertebrates, morphological changes that alter behavior, ecological patterns, and physiological processes are well known. However, the effects of ontogenetic structural changes on insect life-history are not well understood. During development, American locust grasshoppers (Schistocerca americana) exhibit dramatic increases in body size both across and within instars. We have shown previously that as grasshoppers develop across instars, older animals have reduced jump endurance. Within an instar, juvenile grasshoppers nearly double their body mass; however, since respiratory structures only increase during intermolt periods, oxygen delivery may be reduced. We show here that femoral air volume is maintained through structural changes to the leg and that older juveniles within an instar hop less frequently and exhibit greater fatigue than younger grasshoppers. We conclude that morphological changes during development may decrease convective oxygen delivery to the jumping muscle resulting in increased anaerobic metabolism and locomotory fatigue. These ontogenetic changes significantly alter the life-history of juvenile grasshoppers. This research was partially supported by the Union College IEF fund.