Insect Pests of Livestock

1
Insect Pests of Livestock

• Presented by Shannon Williams
• Extension Educator
• Prepared by Kelly V. Tindall
• Extension Entomologist, Twin Falls County

2
Cattle Grub

• Cost beef industry 200 million dollars annually
• Control
• Poor weight gain
• Paralysis (move through spinal canal)
• Secondary infection at opening
• Damage to hide
• Cause gadding (cattle run away from adult
  flies)
• Two species

3
Common Cattle Grub

• Bee-like appearance
• Abdomen has three bands of hairs light yellow
  toward the front, dark in the midsection, and
  orange-yellow at the rear aprx. ½ in length
• No functional mouthparts mate and reproduce on
  energy from stored reserves
• Lays as many as 12 eggs on a single hair on the
  lower part of the body
• Migrate beneath the lining of the esophagus
  lining

4
Northern Cattle Grub

• Similar to common cattle grub
• Larvae or grubs are large, with a segmented
  surface tapered at both ends
• Lays eggs singly on hairs on the lower part of
  the body
• Migrate to the spinal chord
• Life cycle is 1-2 months behind common cattle grub

5
Cattle Grub Biology

• Young cattle are more susceptible than older
  cattle
• Eggs hatch aprx. 4 days
• Larvae penetrate the skin and within 1-2 months
  migrate to the special location
• Live in the location for aprx. 6 mos. (winter)
• Migrate to the back of the animal
• Larva cuts a breathing hole
• Larva make a pouch (warble)
• 6-8 weeks later larva exits, falls to the ground
  and pupates
• Adults emerge within 14-60 days

6
Cattle Grub Control

• Area-wide control more effective than individual
  efforts
• Systemic insecticides 30-60 days after fly
  activity has stopped
• Cattle can be injured or killed following poorly
  timed applications due to the bodys reaction to
  dead grubs
• Common cattle grub swollen gullet causing
  bloating
• Northern cattle grub paralysis of hind quarter
• 48 HAT examine for side effects (bloating,
  stiffening of hind quarter, and excessive
  salivation) contact veterinarian if symptoms are
  seen
• Dipping or pour-on application methods are most
  convenient
• Treated mineral blocks or rations are effective
  if cattle have regular access
• Manual removal breaking larva inside the hole
  can send a cow into shock

7
Face Fly

• Feeds on the secretions of the eye and muzzle
• High incidence of eye disorders
• Tear production and swelling of the eye
• Involved in the mechanical transmission of
  disease
• Causes annoyance and irritation
• Usually pest of range and pasture cattle, not
  confined cattle

8
Face Fly Description

• Nonbiting fly
• Resembles the house fly
• Gray thorax with four dark stripes
• Abdomen of the female is primarily black with an
  orange base and the eyes are surrounded by a
  silvery stripe
• Abdomen of the male is orange-brown with a black
  base and a black dorsal stripe the male's eyes
  almost touch in the center.
• Mouthparts are blunt and do not protrude straight
  like the horn fly and stable fly.
• Larva is yellowish, maggot-like larva, aprx. ½
  inch

9
Face Fly Biology

• Populations increase rapidly, monitor frequently
• Problem throughout most of the summer
• Prefer sunshine, avoid shade, cows may huddle
  together for shade or seek shade
• Eggs laid in fresh droppings
• Larvae develop on dung
• Pupation occurs in dry areas of dung or nearby
  soil
• Life cycle takes 10-21 days
• Can travel long distances

10
Face Fly Control

• Multiple applications
• lt5 of population is present on cattle at a given
  time
• Treated cattle can be reinfested
• Applications are effective 3-5 days
• Spraying and dipping are not practical
• Ear tags or tapes (1/ear) and dust bags are
  normally effective
• Self treating devices must be used frequently and
  constructed to contact the face
• Feeding additives target maggots in dung

11
Cattle Lice Injury

• USDA estimates losses of 125 million a year
• Cause lowered milk production, loss of flesh,
  stunted growth and anemia
• "Chronic" or "carrier (continue to be infested
  despite repeated treatments) cows may abort young
  due to louse-induced anemia
• During severe winters, more susceptible to
  respiratory diseases

12
Cattle Lice Injury

• Fall and spring calves, yearlings, and older
  cattle usually have the heaviest lice
  infestations
• Heavily infested cattle are generally in poor
  physical condition with rough, patchy hair or
  coats that have a dirty appearance
• Moderate to heavy lice populations may reduce
  weight gain of calves by as much as 0.21 lb/day
• Chronic" or "carrier" cows reinfest entire herds
  each year and should be culled

13
Cattle Lice Biology

• Reproduction increases in cool weather
• In the summer, generally found only in the folds
  of skin between the legs and body
• In the winter, populations increase and move to
  the neck, dewlap, muzzle, around the eyes, the
  neck and side of the face, back, sides, and
  tailhead
• Transmitted from one animal to another by contact
• Suckling calves become infested from
  lice-infested cows while feeding, so cows should
  be treated prior to calving

14
Cattle Lice Monitoring

• Infected cattle show signs of excessive
  scratching and grooming (look for hair on barbed
  wire fences or hair loss on cattle)
• White coats may show a dark, greasy appearance
• Lice can be seen by making a two-handed hair part
  in good light (examine the face, dewlap, neck,
  back and tailhead)
• More than three per square inch indicates a need
  for treatment

www.nysipm.cornell.edu
15
Cattle Lice Treatment

• Examine 14 days after treatment to determine if a
  second treatment is necessary
• Most insecticides are not effective against eggs
  therefore reinfestation is common
• Prevent cold stress during the winter by treating
  on a warm day so the cattle will be dry by
  sundown
• Insecticide dust bags used can be used for
  control of lice good for preventing a build-up
• Reduction of heavy populations to non-economic
  levels takes 2-4 weeks
• Ear tags are not effective
• Examine new cattle and treat if necessary before
  adding to herd

www.nysipm.cornell.edu
16
Scabies (Mites)

• Two body segments and 4 pairs of legs (adults) 3
  pairs (immatures)
• Attack any part of the body, especially areas of
  thick hair
• Lesions most commonly occur along the back and
  around the tail
• Reproduction increases during cool weather and
  decrease during hot weather therefore symptoms
  are more evident in winter
• The life cycle is as short as 10-12 days during
  the winter
• Spread from animal to animal by contact
• Causes skin irritation and itching
• Scratching further irritates the infested area
  and causes a scab providing optimum conditions
• Loss of hair during the winter can cause the
  animals death

17
Biting Flies

• Cause stress and discomfort to farm and range
  cattle and result in economic losses
• Disperse rapidly from untreated areas and infest
  cattle
• Lead to unpredictable problems in livestock
  management
• Can transmit diseases while feeding

18
Black Flies

• Small (1/5 in), dark colored, with a humpbacked
  appearance
• Only females bite
• Some species attack birds, but most feed on
  cattle and horses
• Immature stages are aquatic
• Attacks usually concentrated around the ears and
  head
• Sunny, warm days - attacks occur in mid-morning
  and in the evening, ending at dusk
• Biting increases at the onset of storms and may
  occur all day when cloudy
• Major pest of beef and dairy cattle in
  north-central Alberta and limit expansion of the
  industry

19
Black Flies

• Saliva can cause many problems
• swelling of bite
• skin irritation
• "black fly fever allergenic asthma, nausea and
  more systemic effects can also occur
• Asphyxiation from inhaling too many flies
• ? weight gain and milk production
• No studies quantifying losses
• Highly migratory (up to 90 miles), difficult to
  control (reinfestation)
• Breeding sites can be treated, but hard to find
• Relief may come from sprays for other pests
• Some use a salve or insect spray in the ears of
  horses to provide relief to the horse for a
  period of time. 

20
Deer Fly

• Slightly larger than house flies
• Mostly yellow or black with darker stripes on the
  abdomen
• Usually dark markings or patterns on the wings
• Bright green or golden eyes with zigzag stripes
• Confused with horse flies
• More frequently attack humans, whereas horse
  flies usually attack livestock

21
Horse Fly

• Considerably larger than deer flies
• Heavy bodied, with huge heads (large eyes in
  males)
• 3/4 inch to over an inch long
• Smaller species - brown, black or gray, usually
  green eyes with reddish-gold bands
• Larger species - brown to black and may be
  slightly striped
• Usually have clear wings

22
Horn Fly

• Adult - half the size of the common house fly and
  is more slender
• Has piercing-sucking mouthparts
• Brownish-gray to black body with a slight
  yellowish cast
• A set of parallel stripes just behind the head
• Brownish-red antennae
• Two wings with a smoky tinge

23
Horn Fly Biology

• Overwinter as pupae, adults emerge in spring
• May fly distances of 5 miles to find hosts
• Females lay eggs in fresh manure eggs hatch in
  16-24 hours larvae feed on the dung for 4-5
  days then burrow about 1.5 in into the soil or
  the manure and pupate adults emerge 5-7 days
  later
• New generation occurs approximately every 2 weeks
  well into autumn

24
Horn Fly Injury

• Found on those areas of the body where they are
  not likely to be disturbed (base of horns, neck,
  throat, belly, thighs, back, etc.)
• Cause weight loss, reduced milk production, and
  reduced vitality
• May become so annoyed that they may injure
  themselves while attempting to remove the flies
• Infestations have been documented to be
  4,000-10,000 flies per animal in some parts of
  the country

25
Horn Fly Control

• Adults are parasitized by certain wasps
• Also immature stages may be fed upon by ants,
  birds and mice
• Predators and parasitoids are not adequate
  control alone
• Treatments usually initiated at populations of
  100 flies per head
• Dip, spray, dust, pour-on, self application and
  ear tags are effective application methods

26
Stable Fly

• Pale spot behind the head
• Indistinct stripes on the thorax
• Seven dark spots on the abdomen
• 1/4-inch long
• Similar in size and appearance to the house and
  face flies differences are
• Mouthparts stick out like a bayonet from the
  front of the head
• Has a different biting habit (lower leg)
• Easy field identification tip is the behavior of
  biting cattle on the lower legs. Stamping of the
  feet is a sign that stable flies are feeding
  since the bite is painful

27
Stable Fly Biology

• Both male and female stable flies feed on blood
• Each fly feeds several times per day, taking only
  a drop or two of blood at a time
• Often bite while cattle are in the shade around a
  building or under a tree
• Eggs laid in decaying organic matter like wet
  straw or manure-straw mixtures larvae also
  develop in other wet, decaying plant material
  such as spilled feed, silage, and grass clippings
  
• Development from egg to adult takes 3-9 weeks
  depending on weather
• Stable flies overwinter as larvae or pupae in
  piles of larval breeding material

28
Stable Fly Contol

• Management of waste is the first step in pest
  management. Moist manure should be removed weekly
  to disrupt the life cycle.
• Wet straw is one of the best breeding sites
  therefore, do not allow it to accumulate use
  sawdust or shredded paper for bedding
• Spilled feed should not be allowed accumulate and
  cleaned up every 2-3 days.
• Traps for adult flies can be useful in programs
  if enough traps are used, they are placed
  correctly, and they are used both indoors and
  outdoors.
• Outdoor traps they are attracted to vertical
  white panels not more than 30 inches above the
  ground with a carbon dioxide producing bait. One
  trap for every 20 to 30 feet of perimeter of fly
  breeding area. Place near building entrances, in
  alleyways, beneath trees, sleeping areas and
  manure piles.
• Indoor traps ultraviolet light traps kills with
  an electrocuting grid or trap them inside an
  inverted cone. One trap should be used for every
  30 feet of wall.

29
Stable Fly Control

• Biological control agents (parasitic wasps) in
  fly management programs is early in development.
  Some species have proven ineffective without
  supplemental releases there is a lag time of
  several weeks between numbers of flies and
  numbers of parasites.
• An early-season release program can greatly
  increase the population of parasites.
• Research suggests that weekly releases of 200
  parasites per cow can provide effective control
  (may need to be adjusted on individual farm
  basis)
• If insecticides need to be used, select baits and
  pyrethrin space sprays to minimize effect on
  beneficiala.
• No one method should be practice, multiple
  methods will provide better and longer lasting
  results than one alone only products that are not
  harmful to the parasites,

30
General Insecticide Info

• Be aware there are differences in insecticide
  uses between beef cattle and dairy cattle to
  prevent residues in milk.
• Always read and follow the label for specific
  instructions for all insecticides. Never use
  insecticide for uses other than on the label.