Sarah’s notes from Keith Waldron workshop – Flies on the Farm

Keith is a Livestock and Field Crop IPM specialist from NY state IPM program at Cornell University, Geneva, NY.  He works with Dr Don Rutz who is a professor of vet entomology at Cornell

•    Animal health issues
o    Transmission of disease causing agents
o    Decrease milk production & wt gain
•    Annoy/irritate animals and farm workers
•    Off site movement
o    Neighborhood conflicts and public health
•    Control challenges
o    Pesticide resistance and the FQPA (food quality protection act, which has taken some materials off the list allowed). Also the NOP does not allow many materials

Animal Stress= impacts
•    Impacts from flies and mange and lice and other stresses
•    Stresses annually but also over the lifetime

For a 100 cow herd usda data shows 5 to as high as 20% loss due to flies depending on the location, situation and fly population levels

Off farm impacts in some areas leading to publicity, public health, neighborhood relations and litigation

Insecticide resistance (which has been worked on extensively by Dr Rutz)
•    House and stable flies are resistant to many insecticides
•    Fewer insecticides are being registered for livestock use
•    Very few new chemicals on the horizon
•    Fewer are or will be approved for use due to the FQPA (food quality protection act)
•    Note that a resistant fly will fly from one farm to another… carrying that resistance to new locations.  Individual flies can fly up to 5 miles and some species will travel across the whole country in some weather systems.
Therefore Integrated Pest Management is essential on ALL farms not just on organic farms.

insect/arthropod pests of livestock
•    Pest species
•    Biology
•    Environment/habitat
•    Monitoring/threshold
•    Management

•    House flies – mostly in barn
•    Stable flies – mostly in barn
•    Face flies – mostly on pasture
•    Horn flies – some in barn but most in pasture
•    Deer flies – mostly on pasture
•    Horse flies – mostly on pasture
•    Cattle grubs – mostly on pasture and mostly on younger animals
•    Cattle lice – mostly in barn in winter
•    Mange mites – mostly in barn in winter

Summer Active flies that are problems in the barn/confinement
•    House and stable flies
o    House flies, Musca domestica:
•    non biting.
•    Its habitat is undisturbed moist organic matter such as soiled bedding, manure, spilled feed and silage
•    Face does not have anything projecting out of front
•    Life cycle is 10 days, can live 10 to 21 days and lay up to 600 eggs
o    Stable Flies stomoxys calcitrans
•    Biting flies (ankles, legs…. Can lead to hair loss on some animals)
•    Habitat is undisturbed moist organic matter such as straw and manure, spilled feed and silage but also around base of round bales on the ground, grass clippings, pond/lake weeds on shorelines, poorly managed compost piles
•    Life cycle is 21 days. Can live 20 to 30 days and lay up to 400 eggs
•    Temperature has an impact on fly development.  House fly eggs hatch in 23 hours at 68 degrees and in only 8 ours at 95 degrees.  They reach adulthood at 2 to 4 days at 95 and take 10 days at 68 degrees.
•    One fertile female fly can contribute enough flies that with exponential growth there can be 3 million flies by the end of the summer!
•    Common Fly breeding sites are
o    Calf hutches
o    Silo leak and spill areas
o    Animal stalls/pens, feed storage/prep areas, feed bunks, etc, near water sources
o    Calf, hospital and maternity areas
o    Water tanks
o    Feed troughs
o    Manure handling areas

Monitoring Stable flies AND house flies
•    Spot cards
o    3 by 5 cards.  Count or estimate the # of spots.
o    Use a minimum of 5 cards distributed throughout the barn.
o    Put out new cards every 7 days
o    Action Guideline is about 100 spots per card per week
•    Sticky traps/ribbons
o    Minimum of 5 sticky traps/ribbons, distributed throughout the barn
o    7 days per sample
o    Action guidelines:  250 flies/tape/week
For Monitoring Stable Flies (they bite)
•    Count flies on all four legs
o    Count standing animals
o    Minimum of 15 animals
•    Sample every week
•    Action guidelines:  10 flies per animal
•    Most control is sanitation
•    Cultural and mechanical control
o    Disrupt fly life cycle
•    Sanitation
•    Keep it dry
•    Clean up organic material
•    Spread manure thinly and disk in where possible
•    Control moisture
•    Check for leaks, have adequate ventilation, proper grading and drainage, add rain gutters to the buildings
•    Bedding?
•    Keep it dry!!!
•    Change it often enough to break up fly development cycles.
•    If a bedded pack is dry its not much of a problem. If its wet it must be changed frequently or needs to be managed so it is dry.
•    Research on choice of animal bedding material and how that may impact fly population (house and stable).  Showed that straw is a good substrate for fly development so it must be changed frequently or kept dry.  Sawdust use can reduce fly numbers
•    Giant Fly Sticky traps are effective.  Some have pheromones which attract house flies and some have drawn on flies and spider webs which seem to attract flies too.  The long narrow fly tapes on reels also seem to be quite effective.
o    Biological control of house and stable flies
•    Predaceous mites (macrocheles muscadomestica).  These occur on all farms
•    Predaceous beetles such as carcinops or hister beetle
•    Diseases such as beauvaria bassiana or entomophthoroa muscae
•    Beauvaria bassiana is a fungal disease which may already be present on your farm in the fly populations.
o    They are experimenting with putting this fungus out in the barn on rice hulls with a fly attractant/bait station.
o    Preliminary research shows it takes 2 to 3 weeks to impact the fly population.
•    Parasitoids such as muscidifurax raptor or muscidiforax raptorellus.
•    These can be purchased but are expensive
•    What can we do to help them survive longer so we don’t have to be purchased as much or as often?  Don’t use fly killing sprays which will also kill the wasps.  Start releasing in mid to late may.  Do weekly releases.  They are sold as parasitized house fly pupae.  Scatter the pupae near the breeding sites.  The cost is $14per 10,000 per week which is sized for 50 cows.  Some farms use more than this.  Spread the pupae/sawdust mixture in the areas where flies are problems/hatching.  The tiny wasps can either kill or lay eggs in the fly pupae.
•    Make sure that what you are buying are climatically adapted and disease free.  In NY they use muscidifurax raptor and muscidifurax raptorellus which seems to be the species which work best in this climate on dairy farms.  Some other wasps are not adapted to northern climates, are better suited to poultry operations, or have disease which lower their rate of reproduction.
•    Chemical control:  must be NOP listed material.
Pasture fly biology
•    Stable flies:
o    habitat is wet/moist organic material so sanitation is key
o    can fly long distances and may be carried in on storms
•    Face flies and horn flies whole life cycle is in fresh cow pies
•    Deer Flies and Horse flies live in wet areas, streams, pond edges
o    Larval stages are aquatic so difficult to control larval stages

Cultural practices
•    Effective traps mimic the host
•    Effectiveness varies with fly species
•    They reduce but do NOT eliminate populations of problem flies
•    They must be put out of reach of animals
•    Location of the traps is very important
•    They can cost a lot
o    Epps trap.  About 6 feet tall and 6 feed wide.  Flies attracted to large things that stand out from surroundings and tend to circle the host before landing.  They fly into the clear plastic and bounce off into a tray filled with liquid (like soapy water) which they drown in.  It tricks them into thinking they are landing on the belly of a cow.  Great for catching Horse, Deer and Stable flies.  They set it up next to the farm pond where they though the majority of the deer/horse flies were coming from.  $360
o    Horse Pal Trap:  specifically designed to attract and trap flies by resembling the underside of livestock.  Has a black ball that hangs underneath and moves which attracts flies.  They land on and above the ball, move towards light in screened area above and then ultimately are trapped in a jar.  Uses the flies natural instinct to fly upwards and fly towards light.    Catches horse, deer and stable flies. $225
o    Alsynite Trap:  a fiberglass (alsynite) sheet that reflects light into wavelengths that attracts flies (stable flies).  Sheet of transparent fly paper is wrapped around the fiberglass.  Insects stick to this.  The sticky fly paper sheet is removed and replaced when full of flies.  This one catches stable flies. $50
o    No zap/stable fly traps catch stable flies.  $10 commercially available. (farnum)