PHYLOGENETIC RELATIONSHIPS, SPECIES LIMITS, AND HOST SPECIFICITY OF GALL-FORMING FERGUSONINA FLIES (DIPTERA: FERGUSONINIDAE) FEEDING ON MELALEUCA (MYRTACEAE)

Authors: Scheffer, Sonja; GIBLIN-DAVIS, R - UNIVERSITY OF FLORIDA; DAVIES, K - SOUTH AUSTRALIA; TAYLOR, G - SOUTH AUSTRALIA; PURCELL, M - USDA, AUSTRALIA; Lewis, Matthew; GOOLSBY, J - USDA, AUSTRALIA; Center, Ted

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/7/2004
Publication Date: 10/7/2004
Citation: Scheffer, S.J., Giblin-Davis, R.M., Davies, K.A., Taylor, G.S., Purcell, M., Lewis, M.L., Goolsby, J., Center, T.D. 2004. Phylogenetic relationships, species limits, and host specificity of gall-forming fergusonina flies (diptera: fergusoninidae) feeding on melaleuca (myrtaceae). Annals of the Entomological Society of America.97:1216-1221

Interpretive Summary: The Australian paperbark tree, Melaleuca quinquenervia, is highly invasive in the wetlands of Florida. Populations of this weedy tree currently occupy more than 500,000 acres, constituting a considerable threat to the Florida Everglades. Federal and State agencies are working to develop various methods of controlling this invasive plant. Some efforts have involved identifying insect species that feed on this plant in its native range in Australia in order to identify those that might be suitable for release in Florida as biological control agents. A galling fly, Fergusonina turneri, was identified as a potential biological control agent, but the systematics of this species and its close relative were poorly known. This study uses DNA sequence data in order to investigate species limits and host-specificity in F. turneri and its relatives. We found that F. turneri belongs to a group of highly specialized feeders on Melaleuca, Additionally, F. turneri was shown to contain two cryptic species, one of which is specialized to feed only on the paperbark tree. This information will be used by Federal and State agencies interested in the control of invasive paperbark tree populations. This information will be used in a petition asking for permission to release F. turneri in Florida. This information will also be of interest to entomologists and evolutionary biologists.

Technical Abstract: Phylogenetic analysis of recently described gall-forming Fergusonia flies was performed using DNA sequence data from the mitochondrial cytochrome oxidase I gene. Fifty-three flies reared from nine species of Melaleuca were sequenced and found to represent at least nine host-specific species. Species boundaries delimited by mitochondrial data confirm recent morphological investigation with one exception. Fergusonina turneri, believed to feed on both M. quinquenervia and M. fluviatilis, was shown to contain at least two cryptic species, each specialized on one of the two hosts. Because F. turneri is under consideration as a potential biological control agent for invasive M. quinquenerva in the Florida Everglades, understanding cryptic variation and the degree of dietary specialization of this species is critical.