Buckmoths (Hemileuca spp.) are day-flying saturniid moths with diverse
ecologies and host plants. Populations that feed on Menyanthes trifol
iata, known commonly as Cryan's buckmoths, have been found in only a f
ew bogs and fens near eastern Lake Ontario in New York and near Ottawa
in Ontario, Canada. Because of their unique ecological traits, geogra
phic isolation from other Hemileuca populations and the small number o
f sites they occupy, there is concern that the Cryan's buckmoth popula
tions are phylogenetically distinct and should be protected. The Cryan
's buckmoths have not yet been taxonomically described and do not appe
ar to have clear distinguishing morphological characters. Both molecul
ar genetic traits (allozymes and mitochondrial DNA sequences) and an e
cologically based character (host performance) were investigated to de
termine whether these populations possess fixed diagnostic characters
signifying genetic differentiation from other eastern Hemileuca popula
tions. Such differences would merit separate conservation management a
s an evolutionarily significant unit. Our studies showed that the Crya
n's buckmoths clearly belong to the Hemileuca maia species group, but
they could not be readily distinguished from other members of that gro
up by means of molecular genetic techniques. There were no fixed diffe
rences in alleles or haplotypes distinguishing any of the populations
or species, suggesting-recent divergence. Nonetheless, in the host-pla
nt performance experiment only the Cryan's buckmoth larvae were able t
o develop on M. trifoliata, a significant difference from other Hemile
uca larvae tested. The Cryan's buckmoth appears to be unique in host p
erformance and warrants protection and management as an evolutionarily
significant unit. In cases such as this where groups appear to have r
ecently diverged, investigations into ecologically significant traits
may provide indicators of conservation significance as reliable as mol
ecular genetic markers.