IPBRG Investigators: Spence Behmer
Collaborators: Martin Shapiro (Fresno State University), Steve Simpson (Sydney, AUS)
Learning is found in most animals, including insects, and it likely plays a role in a wide of range of activities. Invertebrates, particularly insects, are useful organisms for studying learning because they have relatively simple nervous systems and can be reared and maintained in large numbers with relative ease. We are particularly interested in how learning impinges on feeding and have recently developed, in collaboration with Martin Shapiro, a protocol (based on a Y-maze) for measuring the development and speed of learning in grasshoppers (Orthoptera: Acrididae). With respect to learning, grasshoppers offer some unique advantages over other insects, such as honeybees. First, much is known about their nutritional physiology, which permits broader interpretation of learned behavior related to food acquisition. Second, they readily eat synthetic foods, which means questions can be asked about nutrieint-specific appetitive learning. Third, their hemi-metabolous development allows for testing within and between developmental stages. Finally, since they are diverse, opportunities exist to explore how natural-history traits (e.g. specialists v. generalists, solitary v. gregarious individuals) influence learning abilities.
We believe that grasshoppers provide a system that has great potential for understanding shared processes and phyletic differences of the learning phenomena not only within invertebrates, but also with vertebrates. We also believe that grasshoppers can shed new light on the evolution of learning and the biological constraints on learning in simple systems. Our learning research program has not been particularly active in the past few years, but it is an area that continues to fascinate us. We will pursue learning questions where the opportunities present themselves.
Relevant publications:
Pompilio, L, Kacelnik, A. and Behmer, S.T. (2006) State-dependent
learned valuation drives choice in an invertebrate. Science 313, 1613-1615. [pdf]
Behmer, S.T., Belt, C.E and Shapiro, M.S. (2005) Variable rewards and discrimination
ability in an insect herbivore: what and how does a hungry locust learn?
The Journal of Experimental Biology 208, 3463-3473. [pdf]
Behmer, S.T. (2004) Insect Learning. In: Encyclopaedia of Entomology (Ed. J. Capinera),
pp. 1278-1283. Kluwer Academic Publishers, Dordrecht, The Netherlands. [pdf]
Behmer, S.T., Elias, D.O. and Bernays, E.A. (1999) Post-ingestive feedbacks and associative
learning regulate the intake of unsuitable sterols in a generalist grasshopper.
The Journal of Experimental Biology 202, 739-748. [pdf]
Behmer, S.T. and Elias, D.O. (1999) Phytosterol structure as a basis of food aversion
learning in the grasshopper Schistocerca americana (Orthoptera: Acrididae).
Physiological Entomology 24, 18-27. [pdf]