Research at UK has strongly linked tent caterpillars with Mare Reproductive Loss Syndrome, so naturally people get concerned when those fuzzy little creatures start turning out in great numbers, like this year.
They're back and while there are more tent caterpillars around now than in recent years, they're still not nearly as plentiful as in 2001 when MRLS wiped out about 30 per cent of Kentucky's thoroughbred foal crop.
UK Agricultural Entomologist Lee Townsend says, "Everyone is just a lot more aware of the caterpillars, or certainly in the horse business they are. They're watching for them."
Townsend reminds us, "Back around 2000 we had an outbreak that lasted for 2 or 3 years when virtually every wild cherry tree and a lot of ornamental crab apples were infested. As you drive down the highway now, you can pick out a few trees in a row with lots of tents, but nothing like what we saw back then. That's a relief for most of the horse owners around."
Townsend says now is the perfect time for those farm owners to attack the problem in whatever way they choose because of where the caterpillars are on the trees.
He explains, "As the caterpillars develop, they'll tend to move from lots of small nests on limbs to some central nests that make it easier to treat, and you can take advantage of their behavior so that they're clumped together and you have fewer nests to try to either remove or treat. Once they disperse, we don't have a good way of dealing with them."
And what happens when a mare eats those caterpillars?
Townsend says, "the caterpillars are really hairy, but those small hairs are relatively stiff so if an animal ingests it, some of them lodge in the digestive track and create an avenue for bacteria, and that apparently is the mechanism that ended up with the abortions we saw several years ago."
But with far fewer caterpillars for the horses to eat and better awareness among farm owners about how to dispose of them or have their horses avoid them, there is no reason to expect another outbreak of MRLS.