Giant Swallowtails and Satsumas

Gardeners that have Satsumas, commonly known as orange mandarin (Citrus reticulate), probably have experienced a caterpillar called Orangedog.  It is a chewing insect that feeds on citrus foliage including Satsuma and a few other plant species.  The caterpillar is dark brown with creamy-white, mottled markings and is the larval stage of the giant swallowtail (Papilio cresphontes). It is a striking, wonderfully “exotic”-looking butterfly that is very abundant in Florida. 

Young larva of the giant swallowtail,  Illustrating bird dropping mimicry.
Credit:
Donald Hall, University of Florida

Many who have encountered the caterpillar for the first time describe them as looking similar to bird droppings.  They can grow up to 1.5 to 2 inches in length and are the larval stage of the adult giant swallowtail butterfly.  Established Satsuma trees can easily withstand the loss of a few leaves by Orangedog feeding.  Small or newly planted Satsumas can be infested with numerous Orangedog Caterpillars on occasion, especially a single tree growing in a landscape.

A simple control measure consists of finding and crushing eggs and larva (GH-026). Bt, a biological control for most caterpillar species, is effective but should rarely be used since the beauty of this butterfly far outweighs the damage caused by them.

Adult giant swallowtail, with wings closed.
Credit:
Donald Hall, University of Florida

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