PARENT SESSION
Oral Session #38: Herbivory: Herbivore Response to Plants. Presiding: P. Kleintjes.
Tuesday, August 7, 2001. 1:00 PM to 4:30 PM. Hall of Ideas J.

Ovipositional preferences of a seed eating moth reared on parental and hybrid cattails.

Eisenbach, Jamin¹, ¹

ABSTRACT- Adult females of the oligophagous seed-eating moth Lymnaecia phragmitellacan exhibit an ovipositional preference based upon their larval feeding experience and alternate host availability. Their hosts, the parental cattail species, Typha latifolia, T. angustifolia, and their hybrid T. x glauca, can be found in monospecific, and polyspecific stands. In previous studies, I showed that in polyspecific sites both parental cattails were preferred as hosts over the hybrid cattail. Since these moths are poor flyers and are limited in their ability to choose hosts when monospecific stands are large, I determined whether populations restricted to monospecific sites exhibited fidelity to the type of cattail on which they were raised. Preference in the field was studied by measuring larval densities. Preference in the laboratory was studied by measuring egg densities. Larval densities were determined from seed heads collected from the three types of cattails that had been transplanted into the center of three large monospecific sites in southeastern Michigan. Egg densities were determined from seed heads that had been presented in cages to moths reared from each of the three types of cattails. After correcting for differences in seed quantity, the results showed that moths reared on parental cattails exhibited a preference for the species on which they were raised. Moths reared on the hybrid cattail, exhibited no preference.

KEY WORDS: cattails, hybrids, ovipositional preference, Typha