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in contact. In C. mubeculosus this results in a 180° rotation of the male genitalia, but in most other species there is only a gentle torsion of the male abdomen. Most species mate only once, but Jones (1966) found that C. variipenmis (Coquillett) can mate repeatedly and stored sperm would last for up to three egg batches. Sperm is transferred to the female in a spermatophore in C. nubeculosus (Pomerantzev, 1932) and in C. melleus (Linley and Adams, 1971).
Females when not given a suitable choice of oviposition site may refuse to oviposit, but decapitation can remove this inhibition (Linley, 1965c), and eggs may be deposited freely for experimental studies. Typically the eggs are laid within a week or 10 days after the females emerge in autogenous species or the same length of time after a blood meal. The eggs are small (0.25 mm. long) and banana shaped, white when newly laid and darkening to brown. They are deposited on a moist substrate and cannot survive prolonged drying. The eggs hatch in a few days (2–4 in C. furens and 5–7 in C. barbosai; Linley, 1966b). The first-instar larva possesses a functional spine-bearing proleg.
Linley (1965b) found that C. furens and C. barbosai in Jamaica showed evidence (ovariole relicts) of ability to deposit one (autogenous) or two (second after a blood meal) batches of eggs. Jones (1967) found that C. variipennis females deposit an egg batch for each blood meal
taken. A single female could live up to 44 days, deposit a maximum of 243 eggs in a batch, and lay up to 1,143 eggs in as many as seven egg batches during her lifespan.
Only the most important works on the life histories and larval habitats of the West Indian species will be mentioned, beginning with the early South American and Central American studies of Lutz (1913), Painter (1927), Fox (1942), Carpenter (1951), Woke (1954), and Forattini et al. (1958). The most intensive study of breeding places of neotropical Culicoides was made by Williams (1964) in Trinidad. He reared 24 species from a wide variety of habitats, including sandy and muddy margins of streams and ditches with fresh and brackish water, pond and swamp margins, spring seep areas, discarded animal bedding, rain-soaked manure, decaying cacao pods, banana stalks, calabash fruits, and flowers of Calathea, Heliconia, and Clusia. In the West Indies the only intensive studies of Culicoides biology were made in Jamaica by D. S. Kettle, J. R. Linley, and J. B. Davies, who have published a series of papers on larval habitats, biology, and immature stages. Their findings are reviewed here under each species in Descriptions of Culicoides Species. The West Indies are particularly favorable for those Culicoides species that prefer coastal mangrove Swamps and sandy beaches because of the many miles of shoreline, particularly in the small low islands of the Bahamas. Only the larger islands of the Greater Antilles and Lesser Antilles have area and elevation enough to create constantly wet environments suitable for the rain forest and cloud forest species that predominate on the neotropical mainland. The preferred larval habitats of the West Indian Culicoides species are as follows: (1) Sandy beaches and coastal lagoons—melleus, phlebotomus. (2) Coastal mangrove Swamps and salt marshes—arubae, barbosai,
furens, insignis, trinidadensis. (3) Wet soil and pond and stream margins, usually with organic matter—foci, insignis. (4) Rotting plant materials—foci, jamaicensis, loughnani, paraensis, pusillus. (5) Tree hole debris—borinquemi, hoffmani, paraensis, trilineatus. (6) Leaf axils and bracts of water-holding plants—decor (inferred), dominicanus (inferred), farri (inferred), heliconiae, panamensis. (7) Unknown—archboldi, bredini, floridensis, guadeloupensis.
Literature on Culicoides control has been reviewed by Kettle (1969a) and Linley and Davies (1971).
Several workers have recommended control measures for C. furens using a system of dikes and pumps for water-level management and drying up or flooding potential larval breeding sites (see Hull and Dove (1935), Hull et al. (1939, 1943), Platts et al. (1943), Rogers (1962), MacLaren et al. (1967), and Linley and Davies (1971)).
Working in Jamaican mangrove Swamps producing large numbers of C. furens, C. barbosai, and C. insigmis, Davies (1969) found that C. barbosai preferred more heavily shaded habitats than the other two species. Clearing the mangroves and exposing the soil to full sunlight reduced the population of C. barbosai to a tenth of that in the control area but had little effect on C. furens and C. insignis.
Measures for treating the soil with insecticides to control Culicoides larvae have been proposed by Curran and Goulding (1950), Labreque and Goulding (1954), Jamnback et al. (1958), and Wall and Doane (1965). Use of insecticide sprays and fogs for outdoor control of Culicoides adults has been described by Madden et al. (1946), Glasgow and Collins (1946), and Bruce and Blakeslee (1948). Wire or plastic mesh screens have been only partially effective in preventing Culicoides from entering houses because of the small size of the insects (Porter, 1959). Treating the screens with insecticide in kerosene proved helpful (Jamnback, 1963).
With the recent concern about the long range environmental deterioration produced by massive applications or long continued usage of modern pesticides, advisory agencies have become cautious about recommending chemical control except as a last resort. Emphasis is being
placed on the need for research to develop biological and managemental solutions to sandfly problems.
Hodge (1954) reviewed the Antillean geography and ecology. Woodring (1954) reported on the geological history of the Caribbean. Chace and Hobbs (1969) summarized the West Indian biogeography in a revision of the West Indian terrestrial and fresh-water decapod crustaceans. The maps of the West Indies and Dominica by Chace and Hobbs and the accompanying gazeteers are especially helpful and have been followed in our distribution lists.
The following tabulation summarizes our knowledge of the distribution of the West Indian Culicoides. The format has been adapted from a similar table by Chace and Hobbs. The maps in figures 2–6 illustrate some of these distributions.
The geographic distribution of the fauna is as follows:
Lesser Antilles and Greater Antilles (two species):
Jamaica and Cayman Islands to Barbados and Trinidad—hoff
Puerto Rico to Barbados and Grenada—trilineatus
Antillean fauna also represented on continental masses (15 species):
Lesser Antilles, Central America, and South America (one species): heliconiae—Honduras to Brazil; Grenada Lesser Antilles, North America, Central America, and South America (two species): arubae—Texas to Colombia and Venezuela; Aruba paraensis — Eastern United States to Argentina; Grenada Greater Antilles, North America, Central America, and South America (three species): barbosai — Florida to Panama and Ecuador; Bahamas, Cuba, Jamaica, Cayman Islands
jamaicensis—Mexico to Panama, Venezuela, and Trinidad; Bahamas, Cuba, Jamaica, Puerto Rico pamamensis—Mexico to Panama; Cuba, Jamaica, Cayman Islands Greater Antilles and North America (one species):
loughmani — Florida, Texas; Bahamas, Cuba, Jamaica
Bahamas and North America (two species): floridensis—Florida; Bahamas, Bermuda melleus—Eastern United States (coastal); Bahamas Lesser Antilles, Greater Antilles, Central America (and/or Mexico), and South America (four species): fori-Mexico to Argentina; Jamaica, Puerto Rico phlebotomus—Mexico to Ecuador and Brazil;
widespread in West Indies
pusillus—Mexico to Ecuador and Brazil; widespread in West Indies
trinidadensis—Nicaragua to Colombia and Trinidad; Bahamas, Cuba,
Haiti Lesser Antilles, Greater Antilles, North America, Cen
tral America, and South America (two species): furens—Eastern United States to Brazil and Ecuador; widespread in West Indies insignis—Florida to Argentina; widespread in West Indies
The geographic distribution of the Culicoides species is as follows: * Altigua—furens, hoffmani,” phlebotomus,” pusillus * Aruba—arubae Bahamas—barbosai, furens, jamaicensis, melleus,” trinidadensis Barbados—furens, hoffmani,” paraensis, trilineatus Cayman Islands—barbosai, furens, hoffmani,” insignis,” pamamensis,” pusillus * Cuba—barbosai, furens, insignis,” jamaicensis,” loughmani,” pusillus,” trinidadensis “ Dominica—archboldi, bredini, decor, dominicanus, furens, hoffmani,” insignis,” phlebotomus,” pusillus,” trilineatus * Dominican Republic—furens, insignis,” phlebotomus Grenada — heliconiae, pusillus,” trilineatus * Guadeloupe—furens, guadeloupenSt S
Haiti—furens, insignis, trinidadensis Jamaica — barbosai, borinquemi,
farri, fori,” furens, hoffmani, insignis, jamaicensis, loughmani, pamamensis,” phlebotomus,” pusillus
records are marked with an
Montserrat—furens Puerto Rico—borinquemi, fori, furens, hoffmani, insignis, jamaicensis, phlebotomus, pusillus, trilineatus Saint Croix—furens, hoffmani, jamaicensis, loughnani,” phlebotomus, trilineatus Saint John—furens, phlebotomus * Saint Lucia—decor, furens, hoffmani,” insignis,” phlebotomus,” pusillus,” trilineatus * Saint Thomas—furens,” trilineatus Saint Vincent—decor, furens, phlebotomus Virgin Gorda—furens “
According to Woodring (1954), large insular masses existed in the Caribbean during the Cretaceous and some persisted during the Eocene period. There is no geological evidence, however, of any continuous land bridges or evidence that any
existing land masses were continuously in the Antilles back to the Eocene. Eardley (1954) postulated that a belt of late Jurassic or Cretaceous orogeny branched eastward from Central America through the Greater Antilles and Lesser Antilles to Trinidad and Venezuela. This belt made a tight U-shaped pattern and marked two tectogenes, both formed in late Mesozoic and probably in succession one after the other. A third tectogene from Puerto Rico around the Lesser Antilles to the Leeward Islands formed in the Eocene and continues to the present. These orogenic belts were regions of subsidence, heavy sedimentation, igneous activity, and horizontal compression. At times they may have been seaways, at others, superior mountain systems.