Luna Moth


     The eating habits of the luna moth are quite different throughout its lifecycle stages. One of the most unique and interesting facts about this moth is that the adult does not eat. It has mouthparts, but they are vestigial which means they are not used for feeding ( The adult life stage is very brief, lasting only about seven to ten days, so although the adults do not eat, they can survive off of the food they have stored up as a caterpillar.
     The luna moth caterpillar is quite the opposite of the adult. The caterpillars feed mainly on the foliage (leaves) of birch (Betula), alder (Alnus), sweetgum (Liquidambar), walnut (Juglans), and hickory (Carya) trees. Luna mothsThese tree species can all be found in deciduous hardwood forests, which explains why we see this herbivore in large populations in the eastern United States. The walnut foliage is a special part of the caterpillar diet and is almost specific to this organism alone. Walnut leaves contain juglone, which after careful experimentation, was shown to have negative effects (loss of midgut lining tissue) on many other species. Actias luna, however, showed no negative effects to this otherwise harmful nutrient. Developing a special midgut is one of the adaptations the luna moth has made to ensure it has enough food and does not need to worry about much competition for walnut tree foliage (Thiboldeaux, 1998).
     Another interesting adaptation luna moth caterpillars demonstrate is that their eating habits change depending on where a population is located. Their use of a host plant for food and cocoons is more "specialized at the population or even individual level, rather than the species as a whole. Foliar allelochemicals in  the trees themselves play a role in this host-plant utilization" (Wang, et al., 2003). For example, an experiment was conducted in which Actias luna larva were fed two different types of foliage. When fed leaves of Liquidambar formosanaluna moth (walnut), the larva survived and grew at a good, normal, healthy pace. However, when fed leaves of Cinnamomum camphora (camphor tree) every single one of the larvae died (Wang, et al., 2003). Caterpillars of the luna moth are very specialized with what they eat. Even though the affects of the two types of foliage were completely different, interestingly enough the water and nitrogen contents (important nutrients)were extremely similar (Wang, et al., 2003). The smallest chemical difference can destroy the luna moth diet, which is why the location specialized host-plant utilization is so critical. A caterpillar must be well fed so it can survive its cocoon stage and develop into an adult moth.

To link back to the luna moth Homepage, click here.
For some interesting facts, click here.
To learn more about luna moth reproduction, click here.
To view the gallery, click here.