Mosquito season is upon us. Other bugs too, but today I want to deal with mosquitoes. Clearly these are insects we want to avoid. Mosquitoes are known for their part in spreading the deadly encephalitis viruses horses are susceptible to.
“Chemical warfare” is certainly used to fight mosquitoes. Still, most of us prefer to keep our chemical weapons to a minimum and use natural bug beaters as much as we can. So how can you keep your horses relatively mosquito free in a natural way?
First, minimize mosquito habitat on your farm. We love using big water tubs and troughs in the summer so we don’t have to lug water buckets all day. Those tubs should be dumped at least weekly if not every three days or so to destroy any insect larvae developing in them. Dump and scrub!
If you rely on ponds for water for your horses, consider stocking some native mosquito killers. These include a fish called Gambusia. These are small – one- to three-inch guppy- type fish – that thrive on mosquito larvae. Koi and goldfish do, too, but they aren’t native fish and may not do as well. Or you could add tadpoles purchased from local bait shops. Frogs will eat mosquitoes.
BTI is Bacillus thuringiensis israelensis, a natural-occurring bacteria that mosquito larvae will eat. The bacteria then produce a toxin that kills the mosquito larvae. This will not affect adult mosquitoes and is considered to be safe for birds and other animals who drink from the pond. You would “seed” your pond with this to get a culture growing.
You can also stock your pond with damselfly and dragonfly larvae. The larvae feed on mosquito larvae and adult dragonflies will eat adult mosquitoes. These and BTI can be ordered through many farm and garden outlets.
Birds are big mosquito eaters. That includes lovely hummingbirds – after all they need protein, too! – as well as your traditional bug-eating birds like barn swallows and purple martins. If you provide suitable housing (and in the case of hummingbird additional flowers or feeders) these birds will take up residence and quickly start in on your mosquitoes.
Our barn swallows have already had one hitching and are sitting on a second set of eggs. Be prepared to deal with the possibility of bird droppings in your barn aisle or even on your horse at times. I consider this a small price to pay for the bug control. Swallows zipping in and out of the barn can also desensitize a spooky horse to flapping, flying objects.
While bats cause panic in many people, they are wonderful bug eaters and rarely cause any other problems. You can set up “bat houses” to attract them as well.
There are passive ways to repel mosquitoes from your barn area, too. Many plants serve to repel bugs including mosquitoes. My favorite plants for this are marigolds whose spicy scent is attractive. Rosemary, catnip and citronella grass also perform this duty. Your resident barn cat might really appreciate his own catnip bed.
I have used essential oil mixes to help keep black flies and mosquitoes off my horses’ faces and ears. My favorite is BuzzGuard from Earthheart, which contains Neem seed oil and pure essential oils of citronella, fir, geranium, rosewood, basil and myrrh in water. I like the smell and it does truly seem to help especially with the black flies and mosquitoes. One farm near me burns citronella torches near the barn doors at night hoping to keep mosquitoes out. Obviously, you need to observe those due to fire risk.
A face/fly mask will also help keep mosquitoes off at least part of your horse. Combined with a fly sheet you have additional protection but I do find that mosquitoes will bite right through the fly sheets.
An ideal set up would be a stall with mosquito netting and screens to keep your horse in at night. That simply isn’t realistic for most of us.
Those are my best mosquito fighting tips. I’d love to hear your success stories, too.
Deb M. Eldredge, DVM, Contributing Veterinary Editor