Tuesday, September 14, 2010
Dogs are used for many things these days that assist us. Dogs are featured on the news apprehending criminals, sniffing for bombs and contraband at airports, and searching for people after disasters. Now those impressive nasal powers are being put to a new use.
Some search and rescue (SAR) dogs are augmenting their careers in a new direction. They are being trained to sniff out household pests such as bedbugs and termites, and detrimental insects on crops.
We humans are nasally challenged when compared with our canine companions. Dogs have approximately two hundred million scent receptors to a human’s mere five million. Not to mention those cute wrinkles around a dog’s face and head that enable them to pull in the scents they smell by catching them on the wind as they pass by. A dog’s nose is sensitive enough to pull in a scent as small as a few parts per billion. Imagine how many odors must assault your dog’s nose every time they take a walk.
A dog trained in human search and rescue detects a human’s scent, which can be comprised of respiratory gasses, gasses due to bacterial action on our skin, evaporated sweat, or skin cells that carry our scent as they drop off us. So it only makes sense that dogs would be able to scent out insects. Insects give off pheromones to attract a mate or leave a message for a colony. They can leave a urea trail as well from the excrement they deposit.
While researching this article I was able to speak with Shay Cook. Shay is a partner and trainer for Insect Detection Dogs, LLC and she explained the basics to me. Shay and her partner, Caroline Upton, were both in search and rescue when they met. They developed a successful method of using a dog’s nose to detect vine mealybugs (VMB). Vine mealybugs have been proven as a threat to grape crops and their host range includes citrus, apple, date palm, avocado and fig crops as well. Shay and I spoke about using insect detection dogs for other insect applications and she is working with several institutes to expand the program to other crop pests.
To be a good insect detection candidate, a dog should have a strong prey drive, want to work, and they should have a good nose. You can begin evaluating a dog for insect detection at the tender age of eight weeks old and training begins soon after. A dog imprinting on their handler is very important for any successful partnership. Teaching beginning agility will not go amiss for a dog involved in any kind of search and rescue, because you may find yourself out in the middle of the woods. A dog looking for insects in a vineyard cannot be distracted by people, hoses, sprinklers, or even the supports that hold up the vines.
But how do they teach the dogs to search for insects? Some trainers use pheromone bait, others use dead insects. If you’re searching for an insect feeding on crops, a dead insect won’t help much; you’re looking for the signature of a live one. It isn’t hard to get live specimens, if the pest is considered common and not on a list of species banned by the Department of Agriculture. If the insect is on a dangerous pest list the trainer works with an entomologist to get a sample. They (and their dog) may even go out in the field to see (and smell) the insect in its natural habitat.
It is more conducive for a dog that’s being used to detect insects to work during the cooler hours of the day. The scent is still close to the ground where the dog has to work. It is easier for the dog to catch the scent before it rises in the heat column of the day and becomes so widespread that the dog may not be able to pinpoint the place the scent originated from.
In Minnesota, there are problems with the Emerald Ash Borer and the DNR is watching the gypsy moth. In other states there is a boring beetle (Prionus lecontei) that attacks trees, and another pest that attacks hops crops. There are many benefits to being able to pinpoint a threat to your crops. By being able to pinpoint a specific area of the fields, a farmer is able to use fewer chemical applications to control the pest in question. Early detection enables the farmer to get a handle on a problem before it becomes an infestation and he loses the whole crop.
Read more articles by Ruthie Bently