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  1. HARAR HEALTH SCIENCE COLLAGE DEPARTMENT OF MEDICAL LABORATORY Group Assignment for 2nd Year, Vector Biology Submitted to: Mr. Jemal
  2. TABANIDS (LARGE BITING FLIES)  The various genera and species of tabandis occur around the world. Their family is tabandiae comprises approximately 3000 species of flies worldwide, including the commonly known horseflies and deerflies.
  3. Conti...  They are often large and agile in flight and only the female bite animals, including humans, to obtain blood. They prefer to fly in sun light, avoiding dark and shady areas, and inactive at night
  4. Medically the most important are species:  Heamatopota  Tabanus  chrysops  Species of Tabanus and Chrysops are found in temperate and tropical areas, but Haematopota is absent from South America and Australasia and is uncommon in North America.
  5. Morphology of tabandis  Adult tabandis are very striking.  They are large flies(some species up to approximately 15 mm -30mm), with a short down ward –pointing proboscis and obvious mouthparts.  Many, especially Tabanus species, are robust and heavily built, and this genus contains the largest biting flies, some with a wingspan of 65 mm.  The colouration of tabanids varies from very dark brown or black to lighter reddish brown, yellow or greenish; frequently the abdomen and thorax have stripes or patches of contrasting colours.
  6. Con...  The head is wide and convex (“half-moon” shaped) with large eyes which may be brightly colored  Antennae small and stout (3segments): no antennal arista. Size and shape of antennae for distinction of generas.  Thorax: stout & bear a pair of wings (when at rest like a pair of open scissors)  Abdomen; broad & stout of different colors  Males feed on only sugary secretions. Females also feed on sugary substances but in addition to biting a wide variety of mammals such as domestic animals (esp. Horses, cattles...)
  7. Con.. Figure 1 : adult of deer fly and horsefly  Eggs: creamy white, or blackish Curved, approximately cigar shaped Firmly glued in an upright position in a large mass to the substrate (water proofed)
  8.  Larva: cylinderical and pointed at both ends  Darkish pigmentation near the borders of the segments  Very small black head (can be retracted in to the thorax)  Pupa: brown colored, rounded anteriorly, tapering posteriorly  Has leg & wing cases attached to the body  A row of spines encircling each abdominal segment  Six pointed projections at the apex of the abdomen  Head & thorax combine to cephalothorax
  9. Life cycle of tabandis  Tabandis have complete metamorphosis ( egg, larvae, pupae, and adult).only one generation is produced per year. Eggs are usually laid in large, layered clusters of 100-1000 on vegetation or other objects overlying water or moist soil. The larva undergoes several molts as it grows and depending on the species, the larval stage may last a several months or as long as two to three years.  Once the larva is fully developed it moves into drier soil to pupate. Depending on the species, the pupal stage lasts approximately 5-21 days, and then the adult flies emerge from the soil.  Mating occurs shortly after the adults emerge. Females then lay in wait in vegetation until a host for a blood meal wanders into range.
  10.  figure 3 : life cycle of tabandis
  11. Medical importance of tabandis  Female tabandis can transfer blood borne disease from one animal to another through their feeding habit. Some are:  trypanosomes  filarial worm loa loa  anthrax among cattle and sheep  tularemia, nuisance or painful biting  severe allergic reaction to saliva
  12.  Figure 3: severe allergic reaction to saliva
  13. Control mechanism of tabandis:  the use of repellents or partial repellents is the only effective chemical strategy to reduce the incidence of tabanids on livestock.  Permanent traps (and possibly treated silhouette traps) can be employed to intercept flies.  Selective grazing or confinement can also reduce the impact of tabanids. Stable fly adults are dependent on vertebrate blood for survival and reproduction, but the amount of time spent in contact with the host is relatively small.
  14. Con.....  Stable fly larvae develop in manure, spilled feed and decaying vegetation.  Management of larval habitats by sanitation is the key to stable fly control.  Treatment of animals with residual insecticides can aid in control; thorough application to the lower body parts of livestock is important. Proper use of modified traps, using either treated targets or solar- powered electrocution grids, can be effective in reducing stable fly populations
  15. References 1. Tabanids | Oklahoma State University ( 2. Tabanids: Tabanus species - Horse Flies; Chrysops species – Deer Flies; Haematopota species - Clegs - Learn About Parasites - Western College of Veterinary Medicine - University of Saskatchewan ( 3. 4. 5. Horse-flies (Tabanidae) (Chapter 7) - Medical Entomology for Students ( 6. Biology and control of tabanids, stable flies and horn flies - PubMed (