Chemical basis for host selection byHemileuca oliviae : Role of tannins in preference of C4 grasses.

When provided a choice between grass species with C3 or C4 photosynthetic pathways, larvae of range caterpillar,Hemileuca oliviae Cockerell, selected C4 grasses. The basis for host selection was examined by conducting analyses of moisture, crude protein, total available carbohydrate, sucrose, glucose, astringency, condensed tannin, silica, and pubescence of 14 grass species, and correlating host plant chemical characteristics with host preference. Most of the variation in host preference was explained by tannin characteristics (astringency and condensed tannin); C3 grass species had significantly higher tannin levels than C4 species.