Castniidae are a small family of day-flying moths with approximately 200 species. Most species are found in the neotropical area of Central and South America, with a few in Australia and Asia. In Europe there is only one species, Paysandisia archon, originally native to South America. It was accidentally introduced during the end of the last century and is now rapidly spreading through the Mediterranean area to southern England. It is considered a pest species because its larvae feed on the stems and trunks of palms; In its natural range, the species has natural predators and pathogens that control its numbers so that its impact is minimal. In Europe however, these natural controls are not present and the species causes extensive, and sometimes fatal damage to native palms.
An example of the damage caused to native palms by Paysandisia archon in Greece © StavrosApostolou
The golden sun moth, (Synemon plana), from Australia was once considered as a pest as well. Nowadays it is on the list of endangered species, due to the loss of its natural habitats. Their females are usually flightless and the adults only live for a few days, since they can not feed anymore. When the females emerge from the cocoon they already have fully developed eggs in their body. Its caterpillars are relatively unspectacular and inconspicuous, mostly maggot-like, feeding on palm trunks and stems of sugar cane, banana trees, orchids, bromeliads and many other plants. They are also called cane borer or stem borer moths. They pupate in a cocoon surrounded by palm fibers.
The moth itself is a day-flying with the corresponding club-like antennae, usually of grayish or brownish ground color, some with white stripes and spots and some with yellow or orange parts on the hindwing. The female moths have more colorful marked hindwings to attract the males and they do not have any organs to produce pheromones. At first sight it looks dull but if you get closer you will see quite a colorful and beautiful moth. The body is usually quite thick, so you might guess that it is a very large skipper butterfly. They fly very rapidly and are hard to detect.
Telchin licus from Colombia © Dan Doucette:
Synpalamides phalaris from Brazil: © Sergio Monteiro
Castniomera drucei from Costa Rica, dorsal and ventral view © Dominik Hofer
Xanthocastnia evalthe from Colombia: © Dan Doucette
Interesting news: There is also a Oligocene fossil castniid moth called Dominickus castnioides, found in Colorado. If you look at the genus name, you know why I love these beautiful moths! That they are often considered as a pest is not really the problem of the moth…
Sources and more information:
http://lepidoptera.butterflyhouse.com.au/cast/castniidae.html
http://lepidoptera.butterflyhouse.com.au/cast/cast-moths.html
http://sabutterflies.org.au/moths/synemon-sunmoths.htm
http://entnemdept.ufl.edu/frank/bromeliadbiota/LEPIDBROM.HTM