Biology 625
ANIMAL PARASITOLOGY
Fall semester lecture note outline

Updated: 13 March 2005

1. flies that tend to be robust
2. antennae reduced to 3 segments; terminal segment pointed
3. wing venation is reduced
4. some species nicely colored, with browns, blacks, greens, oranges, etc.
5. larva active and normally predaceous
6. larval cephalic region usually reduced, vestigial, or retractable
7. some representative species in various families listed below
8. good reference book for processing and identifying larval specimens: Stehr, F.W. 1987. Immature insects. Kendall/Hunt Publishing Co., Dubuque, Iowa. Vols 1 and 2. ISBN 0840337027. QL495.5 .I46

FAMILY: Tabanidae (horse flies and deer flies)

1. about 4,000 species in many genera
2. generally large
3. predominately feed during the day; females feed on blood and males feed on plant juices
4. mouthparts with serrated mandibles to cut tissue; maxillae also serrated and pierce further into tissues; blood wells up and ingested (telmophagy)
5. life-cycle
   1. female takes blood meal; males feed on plant juices and nectar
   2. females lay hundreds or thousands of eggs at waters edge; on moist vegetation; in moist soil
   3. larvae with retractable head hatch; 4-9 instars (about 1 week each)
   4. pupate, usually in less moist soil (2-3 weeks typically)
6. common genera in North America include Tabanus, Hybomitra, Haematopota (all "horse flies") and Chrysops ("deer flies"). About 42 spp. are known from Kansas
   1. Chrysops spp. tend to be medium in size, and the wings normally have one or more spots or splotches. The antennae are long with the second segment elongate without any projections. The elongate antennae and splotch on the wings tends to be fairly diagnostic in most cases.
   2. Haematopota spp. are uncommon in North America, but are medium in size, grey, and possess wings that fold roof-like up over the abdomen. Wings tend to be grey and with specks. The antennae are short, with the second and third segments having small projections; the third segment is straight
   3. Tabanus spp. are medium to large is size, normally with clear wings (although some species have dark markings). The antennae are oddly short with the second and third segments having small projections. The third segment is usually curved upwards, which is a dead giveaway.
7. may transmit some diseases
   1. Elaeophora schneideri by Tabanus spp. and Hybomitra spp.
   2. Loa loa by Chrysops spp.
   3. Trypanosoma evansi by Tabanus spp.;
   4. Trypanosoma theileri by Tabanus spp. and Haematopota spp.
   5. may mechanically transmit amoebae and flagellate cysts; bacterial spores such as anthrax and anaplasmosis

FAMILY: Chloropidae (eye gnats) (you will not be tested over this taxon)

1. tiny flies that look much like minitature house flies
2. feed off secretions from body, opportunistically on blood if available
3. vomit stomach secretions onto food to begin digestion
4. common species include Hippolates spp.
5. may be involved in mechanical transmission of several bacterial diseases into wounds. These include Treponema pertenue (yaws) and bovine mastitis on teats. Pinkeye in humans has been shown to be transmitted by these flies as well (among other ways)

FAMILY: Muscidae (house flies and stable flies)

1. small to medium sized flies
2. nearly 4,000 described species
3. most are simply annoying and may serve as mechanical vectors of many diseases
4. Musca domestica (common house fly)
   1. dozens of species within the genus Musca, but M. domestica is very common
   2. four broad, longitudinal stripes on dorsal surface of thorax
   3. wing vein 4 bends upward and joins costa (end of wing) very near wing vein 3. This is an important diagnostic feature for the genus.
   4. females lay 5-6 batches of ca 100 eggs/batch in life
   5. maggots with 3 instars. Depending upon food and temperature, development is complete in 3-24 days
   6. similar genera include Muscina (Muscidae) and Fannia (Fanniidae)
5. includes the stable fly, Stomoxys calcitrans, in North America
   1. looks much like a house fly, but bites and is often called the "biting-house fly"
   2. adults with 4 dark, longitudinal stripes on dark grey thorax
   3. distinct, forward projecting proboscis that is rigid
   4. both sexes feed on blood
   5. feeds during the day; bites many species of mammals
   6. breed in decaying vegetation (i.e. compost piles); sometimes manure
   7. may transmit Trypanosoma evansi and Habronema microstoma
   8. also transmit diseases phoretically, which include anthrax, brucellosis, fowl pox, and others
6. includes Haematobia irritans (horn flies) in North America and elsewhere
   1. look much like a slender house fly; tend to be about one-half size of house flies
   2. both sexes feed on blood
   3. adult flies remain on host, and female only leaves to lay eggs
   4. prefer cattle; occasionally horses and rarely humans
   5. feed on cattle 20-40 times per day
   6. females lay eggs in fresh bovine manure
   7. transmit Stephanofilaria stilesi to cattle; many mechanically transmit other diseases such as bovine mastitis

FAMILY: Glossinidae (tsetses)

1. only one genus, Glossina, with 23 spp
2. predominately sub-Saharan Africa
3. antennae small, plumose
4. generally brownish in color, with base of proboscis bulb-like
5. proboscis forward-projecting and rigid
6. wing veins 4 and 5 enclose a cell that resembles an upside down hatchet. This cell is termed the "hatchet cell" and is very distinctive for the genus
7. diurnal feeders, and like to feed every 48-72 hr if possible
8. both sexes feed on blood
9. home in on carbon dioxide
10. give birth to a single, developed 3rd stage larva; the first two larval stages molt and grow in the oviduct and are nourished by glands termed milk glands
11. females generally lay about 10-15 offspring in their life-time; immediately after birth, larvae burrow into loose, dry, sheltered soil; pupate; 2-4 weeks
12. capable of transmitting African sleeping sickness and related trypanosomes

FAMILY: Calliphoridae (blow flies)

1. most species metallic, and may be blue, green, tan, or other colors
2. many of these have larvae that burrow into the skin and cause destruction of dermal tissue/hides
3. most species with a load buzzing sound
4. Cochliomyia hominivorax (primary screwworm)
   1. occurs in the Western hemisphere, although erradicated in most areas north of Mexico by release of sterile males as females only mate once
   2. infects many types of mammals, especially cattle
   3. adults greenish-blue and metallic with several dark stripes on abdomin; face may also have a patch of color
   4. female lays egg clusters at site of wound (larvae cannot penetrate intact skin); generally dermal tissues infected although the female may lay eggs at the entrance to the nasopharyngeal region or urogenital tract, and around the ears and eyes
   5. larvae emerge from eggs, enter wound (or up nose or urogenital tract); migrate and ingest tissues that can result in deep pocketing of wound (spiracles must have contact with air); after 4-8 days and before pupation, emerge and pupate in soil
5. Other species
   1. Lucilia cuprina (wool strike; in Australia; eggs layed on wet, dirty wool at posterior of sheep; maggots feed on feces, on wool, on the tail, and perianally; may cause inflammation of dermis, irritation of skin)
   2. Lucilia bufonivor (eggs layed on skin of amphibia, especially toads, and larvae migrate to eyes and enter through lacrimal ducts; migrate into nasopharyngeal area from lacrimal gland and feed on cartilaginous septum of nasal cavity; drop out of nostrils and pupate in soil)
   3. Auchmeromyia senegalensis (=A. luteola) (Congo floor maggot); in sub-Saharan Africa; larvae come out at night and feed on sleeping mammals, suck blood; only known genus of blood sucking maggot to target mammals (although others feed off birds). Main hosts wild pigs, warthogs, aardvark, hyena; occasionally humans. Five described species in genus.

FAMILY: Hippoboscidae (louse flies)

1. about 100 species
2. look much like ticks, however, only 6 legs
3. wings have been lost by females of most species, whereas males have usually retained wings; some where both sexes have wings
4. both males and females feed on blood
5. larvae retained in female and larvae ingest secretions from inside female somewhat similar to the tsetses; larvae are born and ready to pupate
6. Melophagus ovinus (sheep ked)
   1. cosmopolitan, although not in tropics
   2. females produce about 1 offspring per week
   3. glues puparium to wool (females produce about a dozen offspring in their lives); lives entire life on host similar to a louse
   4. normally reside on surface of fleece, not directly on skin except when feeding (may not be able to tolerate temperature at dermis); transmitted directly from animal to animal
   5. painful bite; heavy infestations may result in emaciation, scarring, anemia; occasionally bite humans
7. Pseudolynchia canariensis
   1. found commonly on pigeons
   2. temperate regions
   3. both sexes with wings
   4. can transmit Haemoproteus columbae (pigeon malaria)
8. Lipoptena depressa
   1. on deer in the western US
   2. pupae fall to ground; hatch and juveniles fly off
   3. flying juveniles locate deer, crawl between hair fibers to skin to suck blood; become sexually mature in about 12 days
   4. males and females mate on the host
   5. females produce offspring every 3 days; about 30-35 offspring produced per female
   6. some will even feed through the abdomin of other feeding adults

FAMILY: Sarcophagidae (flesh flies)

1. related to Calliphoridae
2. checkered gray and black abdomin; non-metallic
3. most species produce live larvae in wounds or on carcasses; many species infest invertebrates; all parasitic stages during larval period
4. Sarcophaga haemorrhoidalis
   1. cosmopolitan
   2. end of abdomin of adult tipped in red
   3. larvae can sometimes be found contaminating wounds of mammals
5. Sarcophaga cistudinis
   1. chelonians
   2. often found embedded in dermis around neck region
6. Wohlfahrtia vigil
   1. North America
   2. larvae deposited on dermis of many mammals; larvae burrow into skin
7. Emblemasoma erro
   1. North America
   2. larvae parasitize body cavity of various cicadas

FAMILY: Oestridae (bots)

1. this family is composed of several different taxa that were once families on their own; these families are now relegated to subfamilies
2. 4 major subfamilies
   1. Cuterebrinae (rodent or skin bots)
      1. large dark flies that lay eggs near orifices
      2. larvae enter orifice, tunnel under skin, cut out an air hole, and ingest live tissues
      3. many different species in mammals
      4. representative species
         1. Cephenemyia spp. (myiasis in cervids, especially around head and neck;
         2. Cuterebra spp. (infest many species of mammals; often in the skin of rodents, rabbits, and many other mammals
         3. Dermatobia hominis ("Torsalo;" in skin of mammals and birds; female uses arthropod phoretic carrier for eggs)
   2. Gasterophilinae (stomach bots)
      1. females lay eggs to hair; species in horses, elephants, and rhinoceroses; 3 species introduced into the US with equids
      2. Gastrophilus intestinalis (horse bot)
         1. some eggs enter mouth after being licked off
         2. larvae hatch quickly; penetrate tongue epithelium; tunnel to stomach through epithelium; emerge and attach with hooks
         3. after 2 molts, detach in spirng and early summer, passed in feces, and pupae in soil
      3. Gastrophilus nasalis (throat bot; eggs attached to hairs under jaw; lavae hatch and migrate to lips and into mouth)
      4. Gastrophilus haemorrhidalis (nose bot; eggs attached to lips; last stage larvae attach for a time in rectal area)
      5. other members of the genus, and other genera, in other countries
   3. Hypodermatinae (warbles or heel flies)
      1. most species in Northern hemisphere
      2. most species infest cattle, deer, horses; occasional infections in humans
      3. Hypoderma lineatum (gadfly)
         1. light and dark bands on body
         2. females lay eggs on hair, usually on hind legs
         3. larvae penetrate skin; migrate anteriorly, then migrate back to lumbar region
         4. cut air hole in skin in lumbar region; feed on tissues; eventually rupture out of air hole and pupate
   4. Oestrinae (nose and pharyngeal bots; head maggots)
      1. adults large but do not feed
      2. eggs layed in or near nostrils
      3. Oestrus ovis (sheep nasal bot)
         1. targets sheep and goats worldwide
         2. eggs layed in late Summer and Fall
         3. larvae crawl up into sinuses
         4. attached and feed on sinus mucosa
         5. eventually larvae migrate back down, drop to ground, and pupate in Spring
         6. occasionally infections in humans
      4. sneezing, shaking of the head, nasal discharge