Cry proteins, of which Cry34Ab1 is one among many, act by
selectively binding to specific sites localized on the lining of
the midgut of susceptible insect species. Following binding, pores
are formed that disrupt midgut ion flow, causing gut paralysis and
eventual death due to bacterial sepsis. Cry34Ab1 is lethal when
eaten by the larvae of certain coleopteran insects (i.e., corn
rootworms), and its specificity of action is directly attributable
to the presence of specific binding sites in the target insects.