Morphometric and molecular analyses of the sand fly species Lutzomyia shannoni (Dyar 1929) (Diptera: Psychodidae: Phlebotiminae) collected from seven different geographical areas in the southeastern United States /

by Florin, David A

Morphometric and molecular analyses of the sand fly species Lutzomyia shannoni (Dyar 1929) (Diptera: Psychodidae: Phlebotiminae) collected from seven different geographical areas in the southeastern United States David A. Florin, Doctor of Philosophy, 2006 Dissertation directed by: Phillip Lawyer, Ph.D. Department of Preventive Medicine and Biometrics Morphometric and molecular analyses were used to elucidate the variation among the sand fly Lutzomyia shannoni collected from seven widely separated locations in the southeastern United States: Baton Rouge, LA; Fort Bragg, NC; Fort Campbell, KY; Fort Rucker, AL; Ossabaw Island, GA; Patuxent NWRR, MD; and Suwannee NWR, FL. Lu. shannoni is a wide-ranging phlebotomine sand fly has been implicated in the transmission of a number of parasitic and viral pathogens of medical/veterinary importance. In light of this, it is imperative to answer the question of whether or not significant variation exists among the purported biogeographical populations so as to make a determination on the possibility of a cryptic species complex. A balanced approach to answering this question was emphasized by using the two-prong method of morphological and molecular data. The morphometric analysis entailed using univariate and multivariate techniques on a sample size of 40 males and 40 females from each collection site (with the exceptions, due to inadequate number of collected specimens, of Baton Rouge where morphometrics were not conducted for the specimens of either iv gender and of Suwannee NWR where morphometrics were not conducted on the male specimens) A total of 54 characters from the male specimens and 49 characters from the female specimens were measured by an inserted micrometer in the ocular eyepiece of a compound microscope. Results indicate that while there is a certain amount of variation, it is not sufficient to discriminate among the collection sites. Two molecular markers, the mitochondrial DNA CO I and the nuclear DNA ITS2, were PCR-amplified and the resulting sequences compared. For both markers, the small amount of variation observed in the sequences did not have a diagnostic distribution and were not informative in distinguishing the specimens based upon collection site. There may exist one population of Lu. shannoni throughout the United States. In a corollary study, the population dynamics of Lu. shannoni were examined at the Patuxent NWRR, MD from June 23, 2005 to June 15, 2006 by conducting weekly light trap collections. The abundance pattern appears to be unimodal although only multi-year data can provide a definitive determination. v Morphometric and molecular analyses of the sand fly species Lutzomyia shannoni (Dyar 1929) (Diptera: Psychodidae: Phlebotiminae) collected from seven different geographical areas in the southeastern United States by David A. Florin Dissertation submitted to the Faculty of the Department of Preventive Medicine and Biometrics of the Uniformed Services University of the Health Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy, 2006 vi