The Sand Flies (Culicoides) Of Florida

Except for mosquitoes, probably no other in­ sects in Florida cause more human discomfort than the tiny biting midges which in Florida are commonly called sand flies. Especially along some sea coast areas these little flies, almost invisible to the unaided eye, can make life intolerable in early morning, all day on overcast days, around dusk, and all night on warm, moonlit nights. So small that they can easily pass through ordinary 16-mesh wire screen and mosquito netting, they bring misery to many a picnicker, bather, fisherman, hunter, and camper. In addition to the con­siderable discomfort which they can cause, many species are intermediate hosts and vec­tors of filarial worms, protozoans, and viruses which affect man and domestic animals, as well as many wild animals. To many people the le­sions produced by their bites last longer and are more painful than those of most mos­quitoes. Some species of Culicoides which oc­cur about saltmarsh and brackish water areas are extremely abundant at certain times of the year and are difficult to control. Localities at fresh water inlets of the seacoasts and on streams leading to these inlets are places where sand flies are most numerous.

Sand fly annoyance is affected by temperatures and wind. Different species of sand flies occur during different seasons when there are different atmospheric temperatures, but all are most annoying to man when there is no breeze. Animals having a high body temperature attract-large numbers of the blood-sucking females. Only female sand flies take blood, most females requiring this for egg maturation. In subtropical southern Florida one may encounter some of them during any month, although they are generally fewer in numbers during the comparatively dry winter months. Some species have 2 generations a year, while others have only 1.

Sand flies have played a major role in delay­ing the development of some parts of Florida as tourist attractions, recreational areas, and residential areas. Control of the numerous species depends upon a thorough basic knowledge of the taxonomy, morphology, biology, ecology, and the geographic and seasonal distribution of the various species. The hematophagous habit of female Culicoides incriminates them as possible vectors of many pathogens. An accurate knowledge of the feeding habits of these flies is an essential part of-the study of their bionomics, since only those which feed both on the animal reservoirs of the parasites and on the victim of the disease can be involved in pathogen transmis­sion. Drs. Blanton and Wirth present here a comprehensive treatment of those species known to occur in Florida. Each species is described in detail, and keys are presented for identification of adults, pupae, and larvae oc­curring in this area, plus diagnostic tables for quick identification. Key characters for every species are illustrated, and there is a Florida distribution map for every species.

Culicoides are recorded from all major land masses of the world. The genus is large; Wirth, Ratanaworabhan, and Blanton (1974) recorded 924 valid species, and more recent contribu­tions of many workers have increased this number. Wirth (personal communication), in April 1979, stated that there are 122 species of Culicoides described from North America and 1,007 from the world; 47 species are known to occur in Florida.

Dr. Franklin Sylvester Blanton, known to many of his friends as “Syl,” was born in Jones Mill (now Frisco City), Alabama, on 12 December 1902, son of Franklin H. and Martha Ada Blanton. In 1942 he married Audrey Quevedo and sired 2 daughters, Virginia and Martha, and 1 son, Frank T. Blanton. His degrees include the Bachelor of Science in Agriculture, University of Florida (1929), with a major in entomology and plant pathology; Master of Science, Cornell University (1941), with a major in medical entomology and minors in economic entomology and ecology; and Doctor of Philosophy, Cornell University (1951), with a major in medical entomology and minors in parasitology, ecology, and taxonomy of Diptera. He began his professional career in May 1929 with the United States Department of Agriculture at the laboratory in Orlando, Florida, as an agent on the Mediterranean Fruit Fly Control Program. In April 1931 he was transferred to Babylon, Long Island, New York, to work on the control of insects and nematodes affecting ornamentals and greenhouse plants; he was in charge of the laboratory from 1936-42. He was drafted into the United States Army in October 1942, and in November 1942 was commissioned 1st Lt. at the Medical Field Service School at Ft. Joe T. Robinson. During World War II he served 3 tours as Chief Entomologist in the Surgeon General’s office and spent a year (August 1945-June 1946) on duty in New Guinea and the Philippine Islands and later in Japan and Korea working on control of scrub and epidemic typhus. While assigned to the USDA Laboratory in Orlando during 1948-49, he [had] special assignments at the University of Florida in 1951 (studied biology of saltmarsh sand flies), USDA Laboratory in Kerrville, Texas in 1953 and 1955 (established the vector of bluetongue disease of sheep), Museum of ComparativeZoology in 1961 (acted as consul­tant to MCZ in rearranging taxonomic collec­tions of Diptera), New York in 1963 (assisted Dr. Hugo Jamnback in preparation of an authoritative manual on the classification and biology of the New York species of Culicoides), Smithsonian-Archbold-Bredin Biological Survey of Dominica (3 months of field work in spring of 1965 in the course of which the largest single collection of West Indian Diptera was collected), Panama in 1967 (a study of breeding places of Neotropical biting midges indicated that rotting fruits and other plant materials are more important than soil habitats in the rain forest), the Great Plains in 1969 (studied biting midges and brine flies breeding in saline and alkaline lakes and marshes, particularly in waterfowl refuges), Euro­pean museums in 1957 and 1973 (studied type collections of early taxonomists in the impor­tant collections in London, Paris, Vienna and Brussels, and several lesser collections in other cities). Dr. Wirth is author or coauthor of 253 scientific publications, mostly in the fields of public health and taxonomy of several groups of Diptera, including Ephydridae, Dolichopodi­dae, and Ceratopogonidae. He is generally recognized as the world’s foremost authority on the family Ceratopogonidae.

Howard V. Weems, Jr.
Editor

Bureau of Entomology
Division of Plant Industry
Florida Department of Agriculture and Consumer Services
29 April 1979