Path

• Classes of arthropods

  • insecta: insects
  • Arachnida: mites, ticks, spiders
  • Crustacea: crayfish, copepods
  • Pentastomida: tongueworms
• Characteristics of insects

  1. 3 body divisions - head, thorax, abdomen
  2. 3 pairs of legs
  3. sometimes wings
• Diptera are two winged insects
• Examples of diptera

  • mosquitoes
  • house flied
  • blue bottle flies
  • bot flies
• Life cycle of diptera

  egg --> larva (1) --> larva (n) --> pupa --> adults
• Order Diptera, suborder nematocera characteristics

  • long segmented antennae
  • piercing - sucking mouthparts
  • female only blood feed
• Order Diptera, suborder Brachycera

  • stylate antennae
  • slicing mouthpart
  • both sexes blood feed
  • loud fliers
  • persistent
  • painful bites
• Order diptera, suborder cyclorrhapha

  • feathery antenna
  • variable mouthparts
• what is the genus name for a mosquito

  culicidae
• What are the 2 sub families of culicidae

  1. culicinae (northern)
  2. Anophelinae (southern)
• Musca domestica is also known as the uncommonly filthy house fly
• characteristics of house fly

  • robust, hairy
  • aristate antennae
  • sponging lapping mouthparts
  • strong flier
• Life cycle of house fly

  • eggs laid on organic debris
  • maggots eat organic debris
  • pupation in soil
  • prolific
• Stomoxys calcitrans is also known as the stable fly
• characteristics of stomoxys calcitrans

  • also known as the biting house fly
  • aristrate antennae
  • bayonet shaped mouth parts
• Life cycle of stomoxys calcitrans (stable fly)

  • eggs laid in decaying vegetation
  • maggots develop in damp straw
  • pupation in soil (overwinter)
  • adults attack mid day by piercing skin for blood
• Biting and non-biting flies control summary

  1. sanitation measures
  2. removing manure
  3. removing rotting vegetation
  4. removing standing water or muck
  5. 2. Insecticides
  6. ear tags
  7. spray on formulations
  8. back rubbers
  9. chitin inhibitors in feed
• Sheep Keds characteristics

  • wingless fly
  • flattened dorso-ventrally
  • leathery and hairy
  • complex metamorphosis
• Significance of Sheep Ked

  • irritation
  • blood loss
  • wool damage


  Control

  • tropical insecticides
  • usually a winter issue
• Myiasis

  • invasion of healthy or damaged flesh by the larvae of dipteran flies
  • both obligate and facultative myasis (starts with wound that attracts flies)
• Myiasis - Sarcophagids and Calliphorids life cycle

  • eggs laid in wound or decaying carcass species
  • specific level of decomposition preferred
  • larvae develop at or near site of oviposition
  • mature larvae leave host to pupate
• Major types of bot flies and their host

  • warble fly - cattle, rarely horses
  • nasal bot fly - sheep
  • rodent bot fly - small animals
  • stomach bot fly - horses
  • human bot fly
• General Bot Fly Features

  • large, bee-like adults (these adults don't feed)
• Hypoderma bovis - northern cattle grub

  • larvae overwinter in spinal canal or epidural fat
• Hypoderma lineatum - southern cattle grub

  • larvae overwinter in esophageal connective tissue
• Hypoderma lineatum and hypoderma bovis causes obligate myiasis
• Life cycle of the hypoderma species

  • eggs laid on legs of cattle
  • larvae penetrate skin and migrate to overwintering sites for about 3 months (Dec)
  • by later Feb-Apr they migrate to back
  • produce "warble" there (subcutaneous cyst)
  • larvae mature and drop out of wound and pupate
  • one cycle per year
• Cuterebra morphology

  • bee-like fliers
  • vestigial mouthparts
  • large larva with spines within subcutaneous cysts of host
  • causes obligate myiasis
• cuterebra life cycle

  • eggs found near burrow openings
  • larvae enter host via nose or mouth
  • migrates to skin and cuts breathing hold
  • larvae emerges when mature
  • pupation on ground
  • adults mate and lay eggs
• Cuterebrae Clinical signs

  • subcutaneous fibrotic cyst
  • wet coat in neck region
  • small hole
• Gasterophilus species life cycle

  • eggs on forelegs
  • oral migration
  • 2nd stage larva when swallowed
  • larva overwinter in stomach
  • larvae pass out with feces
• Gasterophilus Signs and controls

  • usually asymptomatic but gastric lesion can be significant
  • use insecticides and endectocides
• Anophelinae Characteristics

  • warm temperature
  • twilight feeders
  • larvae hang horizontally in water
• Black Flies Characteristics

  • associated with running water
  • biological vectors of river blindness
  • painful and annoying biters
• Characteristics of Midges

  • associated with still water
  • dappled wings
  • small
  • transmit arboviruses and other agents of disease
• Sucking Lice Characteristics

  • highly host specific
  • feed on secretions and blood
  • wingless, and flattened
• Sucking Lice Life Cycle

  • simple metamorphosis
  • eggs demented to hairs
  • life cycle is 2 - 4 weeks
  • entire life cycle on the host
  • found in groups attached by mouths
• Biting lice characteristics

  • highly host specific
• Biting lice characteristics

  • highly-host specific
  • feed on skin, hair, secretions, feathers
  • wingless, flattened
• difference between sucking lice and biting lice

  • sucking lice head is narrow and biting lice heads is as broad as thorax