Gypsy moth larvae, Lymantria dispar (L.), are highly polyphagous and display a wide host preference, feeding on the foliage
of many species, but favoring leaves of deciduous hardwood trees, such as oak, maple,
and sweet gum. Gypsy moth larvae are major pest defoliators in the United States and
destroy millions of acres of trees annually. These lepidopteran insects possess gustatory
sensory organs located on the maxillae, namely the medial and lateral galeal styloloconic
sensilla, which play an important role in host-plant selection. Using a single cell
electrophysiological recording method, this study characterized the sensitivity of
the receptor cells housed within each sensillum of gypsy moth larvae when exposed
to a panel of selected phytochemicals by performing dose response experiments. Electrophysiological
tip recordings from these sensilla revealed that medial styloconic sensilla responded
to the alkaloids, strychnine and atropine, while lateral styloconic sensilla responded
to aristolochic acid and atropine. In general, these different taste cells exhibited
characteristic temporal firing patterns. Thus, this study provides correlative insights
into the feeding behavior and taste physiology of this larval insect. It also provides
a gateway to use other alkaloids in temporal and dose-response experiments as a possible
means of biocontrol.
