On a warm night last August at a restored pitcherplant bog in south Georgia, more than 100 species of night-flying Lepidoptera visited our light.
The moths sported various patterns and hues: grays, blues, greens, yellows and pinks. Some also were cryptic, perfectly resembling mosses, bark and leaves.
Yet although we recorded each species to create a site inventory, all were secondary to our goal. We were searching for Exyra and Papaipema genera moths, secretive species that depend on pitcherplants.
Moths, like other invertebrates in the order Lepidoptera (which includes moths, butterflies and skippers), are usually specialists that require certain host plants.
Pitcherplant moths – two of Exyra’s three species have been documented in Georgia – evolved to survive on their namesake plants. The caterpillars rely on this predatory plant as their larval food. And, they are uniquely equipped to avoid the plant’s dangers.
Unlike most insects, these caterpillars have claws that allow them to grip and move along the underside of the plant hoods.
This saves them from falling into the caustic pool of digestive enzymes in the tubular leaves of purple, red and hooded pitcherplants. These animals even use this unfriendly environment as shelter from inclement weather and potential predators at all stages of life, from minuscule egg to crawling caterpillar and fluttering moth.
Pitcherplants are also the required larval food for the pitcherplant borer moth, a Papaipema species.
Instead of eating leaves, however, these caterpillars eat roots. Borers have been known to tunnel up to 1 foot into the root ball underneath a clump of pitcherplant. This keeps the passage clear by pushing the frass out. Although the species has been found in coastal bogs in surrounding states, it has not been documented in Georgia.
That evening a year ago and on subsequent nights, we did not spot any of the pitcherplant or borer moths. But we did see hundreds of other species, a sample of Georgia’s rich wildlife diversity.
By ANNA YELLIN. Georgia Department of Natural Resources