Equine Insects Flashcards
Gasterophilus spp.-Common Name
Bot fly larvae or instars
Bot fly
Gasterophilus spp.-Hosts
Equine
Gasterophilus spp.-Identification
Adults: large flies, 18mm long, irregular dark transverse bands on the wings
L3 or instars: red with 2 rows of coarse spines blunted on ends (G. intestinalis) or yellow with 1 row of spines on each segment (G. nasalis)
Gasterophilus spp.-Life Cycle
ELPA.
Egg hatches to 1st instar→in oral cavity devel. to 2nd instar→ swallowed and devel. to 3rd instar→ pass in feces and pupate→ adult
Gasterophilus spp.-Site of Infection
Eggs on hair of forelegs and shoulders (G. intestinalis) or intermandibular area (G. nasalis)
3rd instars attach in clusters in non-glandular part of the stomach near margo plicatus and cardiac region (G. intestinalis) or duodenal ampulla (G. nasalis)
Gasterophilus spp.-Pathogenesis and Lesions
Adult flies cause an annoyance
Attached instars provoke an inflammatory reaction
Gasterophilus spp.-Clinical Signs
Fly worry
Gasterophilus spp.-Diagnosis
Differentiate bases on color, spines and location in host
Seen during gastroscopy
Gasterophilus spp.-Treatment and Prevention
Manual removal of eggs
Endoparasiticides for larval stages
Musca autumnalis-Common Name
Face fly
Musca autumnalis-Hosts
Equine
Musca autumnalis-Identification
Adults: 5.5-7.5mm, mouthparts adapted to sponging, sticky hairs on pad-like structures at end of legs
Eggs: 1mm long and banana-shaped
Musca autumnalis-Life Cycle
ELPA
Eggs devel. to larvae (maggots)→ 3 larval instars→ pupae→ adult
Musca autumnalis-Site of Infection
Feed on face secretions and on wounds
Musca autumnalis-Pathogenesis and Lesions
Source of annoyance
Mechanical transmission of viruses, bacteria, helminths and protozoa
Musca autumnalis-Clinical Signs
Annoyance can lead to decreased grazing and drop in performance
Eye disorders and conjunctivitis
Musca autumnalis-Diagnosis
Fly identification
Musca autumnalis-Treatment and Prevention
Face screens
Insecticides
Stomoxys calcitrans-Common Name
Stable fly, biting housefly
Stomoxys calcitrans-Hosts
Most animals, including humans
Stomoxys calcitrans-Identification
Adults: 5.5-7.5mm, mouthparts are rigid, conspicuous and forward projecting
Eggs: 1 mm, banana-shaped, creamy white
Stomoxys calcitrans-Life Cycle
ELPA
Feeds on blood
Requires 3 mins per blood meal
Females lay eggs on decaying matter such as damp hay
Stomoxys calcitrans-Site of Infection
General
Stomoxys calcitrans-Pathogenesis and Lesions
Attack animals on warm days
Transmit disease organisms
Bite is painful
Stomoxys calcitrans-Clinical Signs
Increased head and ear movement, skin twitches and tail swishes
Stomoxys calcitrans-Diagnosis
Fly identification
Stomoxys calcitrans-Treatment and Prevention
Screens, sanitation to reduce breeding sites, various insecticides, treat horse and environment, DO NOT treat compost
Culicoides spp.-Common Name
Biting midges, “no-see-ums”
Culicoides spp.-Hosts
All domestic animals and humans
Culicoides spp.-Identification
Adults: 1.5-5 mm long, molted wings, short piercing proboscis
Culicoides spp.-Life Cycle
ELPA.
Eggs laid in damp marshy ground→ hatch in 2-9d→ 4 larval stages→ pupatae at edge of water→ adult in 3-4d
Adult females suck blood
Culicoides spp.-Site of Infection
General
Culicoides spp.-Pathogenesis and Lesions
Annoyance, transmits viruses, helminths (Onchocerca) and protozoa
Culicoides spp.-Clinical Signs
Painful bite, “queensland itch”, allergic dermatitis
Culicoides spp.-Diagnosis
Id identification
Culicoides spp.-Treatment and Prevention
Decrease standing water, avoid marshy pastures, treat horse with repellants/insecticides
Tabanus spp.-Common Name
Horse fly, gadfly
Tabanus spp.-Identification
Adults: Stout bodied fly 10-50mm, mouthparts slashing and sponging
Tabanus spp.-Life Cycle
ELPA.
Eggs laid in muddy or marshy areas→ hatch in 1-2wks to sluggish larvae→ papae→ adult
Takes 4-5 mths
Tabanus spp.-Site of Infection
General
Tabanus spp.-Pathogenesis and Lesions
Painful bites, mechanical vector of anthrax, pasteurellosis, trypanosomosis, anaplasmosis and loasis
Tabanus spp.-Clinical Signs
Annoyance
Tabanus spp.-Diagnosis
Id fly
Tabanus spp.-Hosts
Almost all animals
Tabanus spp.-Treatment and Prevention
Insecticides, repellants, eliminate standing water
Chrysops spp.-Common Name
Deer fly
Chrysops spp.-Hosts
Almost all animals
Chrysops spp.-Identification
Dark bands across wings, antennae elongate
Similar to Tabanus spp.
Chrysops spp.-Life Cycle
ELPA.
Eggs laid in muddy or marshy areas→ hatch in 1-2wks to sluggish larvae→ papae→ adult
Takes 4-5 mths
Chrysops spp.-Site of Infection
General
Chrysops spp.-Pathogenesis and Lesions
Painful bites, mechanical vector of anthrax, pasteurellosis, trypanosomosis, anaplasmosis and loasis
Chrysops spp.-Clinical Signs
Annoyance
Chrysops spp.-Diagnosis
Id fly
Chrysops spp.-Treatment and Prevention
Bite horses in shaded areas, horses will stand in sun to avoid
Insecticides/repellants
