11/16/05 - Redbay mortality threatens the Palamedes swallowtail

Received from:
Dr. John L. Foltz, Forest Entomologist
University of Florida
Department of Entomology & Nematology
PO Box 110620
Gainesville FL 32611-0620
Phone: 352-392-1901 x 130
Fax: 352-392-0190
Email: foltz@ufl.edu

Many of you are already aware that an undescribed Ophiostoma fungus, very likely vectored by a recently-arrived Asian ambrosia beetle, is killing Persea borbonia of all size classes along the coast from Hilton Head, SC to Jacksonville, FL. Preliminary data indicate that tree mortality may be similar to that produced by Dutch elm disease. Along with the many questions we have about the biology, ecology, and management of the pathogen and vector(s) are questions about the impact of redbay mortality on other flora and fauna.

The purpose of this mailing is to point out that Papilio palamedes, the Palamedes swallowtail, is dependant on redbay and swamp bay (Persea palustris) as larval hosts. The geographic range of this swallowtail is coincident with that of redbay, major populations of both species being limited to the coastal plain from Delaware to Texas. A 90% reduction in redbay would very likely cause an even greater reduction in flights of this well-known summer and fall swallowtail.

ONLINE REFERENCES. Here are some links for more information about the palamedes swallowtail and redbay wilt:

Overview of redbay ambrosia beetle, Xyleborus glabratus

Silvics of redbay, Persea borbonia

Palamedes swallowtail, Papilio palamedes

Do you know of other examples of probable/possible ecological impacts of unchecked redbay wilt? If so, please share them with me.

The UF/IFAS Pest Alert WWW site is at: http://entomology.ifas.ufl.edu/pestalert/