Oh Dear - Deer Fly

This really rain soaked spring and summer have made us terribly aware of mosquitoes.  Ticks are rampant and the diseases these two bring can be devastating to health.  Gnats are swarming like low clouds and even though they aren’t a huge biting machine, they're certainly pesky.  And that brings me to Horse and Deer Flies.

Anyone who has large animals knows these biting insects.  And now it seems my yard has become new “fresh meat” for these stout, broad-headed and brightly eyed flies.

Deer Flies (Chrysops) live in deciduous and mixed forests, meadows, roadsides and suburbs near water in all of North America.  Yep, that would be all of us in the Galva News reading area.

The male drinks plant juices and is a pollinator.   The larva feeds on small aquatic insects.  Seems good on both counts.  And then there’s the lady of the house.  Her only meal of choice is the blood from mammals.  Yes, she’s a bloodsucker.  In June/July she feasts upon the unsuspecting. 

Great Golden Digger Wasp 
(good insect)

Whereas we usually hear mosquitoes, the flight of the deer fly is mostly silent.  They land stealthily on exposed skin and deliver a painful bite.  Their favored place to bite humans is the neck and face but will bite any exposed skin.  Its mode of attack is to silently circle over it’s intended victim before settling and it immediately bites.  They can bite repeatedly.   

The Horse Fly is a related beast, larger and likes the blood of large mammals.  The wound inflicted often continues to bleed for several minutes because both of these fly’s saliva contains an anticoagulant that prevents clotting.

The female doesn’t sting, her bite makes a cross-like incision and she laps up the resulting blood.  Along with the bite being very painful, some people have an allergic reaction to the fly’s saliva.  People who are allergic often have increased reactions with each new bite. They may also carry tularemia, anthrax, loa loa filariasis, several kinds of animal infections and are suspected carriers of Lyme disease.

In the large mammal industry, their bites are considered to cause millions in lost revenue, especially in dairy cattle whose milk production is diminished and weight loss in beef cattle.  20-30 flies feeding six hours on an animal can take 100 cc of blood. There are specific repellents for specific animals.  Up-to-date advice from your veterinary is available.  

Demoiselle Calopteryx virgo 
damselfly (good insect)

Encourage nest-building wasps, hornets, dragonflies and killdeer birds because they feast on the flies.

The flies use sight to find prey and may also be attracted CO or certain odors.  Moving objects, especially dark colored objects are most prone to attack.  The first peak biting time is sunrise for about three hours.  The second peak time is the two hours before sunset.  They are out the least on overcast, windy and cool days.  Heavy shade protection for animals will help.

Since it’s impossible to eliminate their breeding grounds, especially in this wet weather, protection from bites is the best effort.

Traps are somewhat useful in small-managed areas.  Covering yourself with light colored clothing is suggested.  The old fashioned sticky fly strips hanging from branches or your hat may work but remember they are VERY sticky to humans also.

Then the one that seems to work if you’re not concerned about looking like the crazy person next door:  Covering a blue plastic cup or inverted blue plastic mixing bowl in a liberal coating of petroleum jelly and attaching this contraption to top of your head.  These can also be tied to a string and hang from tree limbs or to your mower.  The swaying in the breeze seems to attract them and then they stick.  They are super attracted to swimming pools areas.

Blue Dasher Dragonfly 
(good insect)

Some sources suggest using an insecticide with DEET while others say it only attracts.  For me, insect spray doesn’t deter the pesky critters.  Covering seems to be my best bet. Netting over your hat and head works for flies and mosquitos.  I recommend the Bishop Hill pilgrim’s cotton bonnet in a light color.  (Several of the B.H. stores carry them.)  Mine extends over the back of my neck. Yes, I seriously look like granny from the Beverly Hillbillies and I’m OK with that if it means I won’t be bit.

I’m using liberal amounts of pure colorless vanilla.  I may smell like a cake but I’m one of those people who has an allergic reaction and it’s not pretty.   Others recommend the oils of garlic, lavender, peppermint and Eucalyptus.  Dab it on a bandana and tie around your neck, on your hat, or clothing.  Some of these may stain clothing or irritate skin.

With all these recommendations, I expect to see you gardening in white clothes, a netted hat with a blue SOLO cup died to the top of it, smelling like a herb oil factory while several fly strips cling to various parts of your body.  Dang I love gardening for its humor if for nothing else.