SIERRA VISTA — If you are one of those people that just can’t stand bugs, the normal reaction when you see one is to squash it flat.

But, wait. Don’t break out that insecticide sprayer. According to entomologist Carl A. Olson, all bugs have a purpose in this world — recycling. So, if you kill it, there’s a part of the natural cycle of things that has been disrupted.

In his talk Sunday afternoon at the Carr House, part of the Friends of the Huachucas program, he explained to a packed room his position on live and let live, even when it comes to seemingly pesky insects.

“We have to change our attitudes. Insects are important to the ecosystem around us,” he says.

The Bug Man, Carl A. Olson, talks with 5-year-old Lance Cowdell and Garrett Cowdell, 7, before his lecture at the Carr House on Sunday. Olson, the author of “Insects of the Southwest,” discussed how to co-exist with insects peacefully. (Suzanne Cronn•Herald/Review)

There are several reasons bugs show up in gardens or plantings — simple survival is the main one. All bugs need food and water just like us human critters.

“The tiny insects that drive us crazy buzzing around our faces are just there for a quick drink. We attract them because of the chemical signatures we give off,” he said. “We’re an oasis for them.”

Along with food and water, they also need little niches in which to set up house. So any little nook or cranny can become a homestead for a six-, eight, or more-legged creature.

The only way to protect your plants and trees from insect attack is to be sure the plants are in the right soil and have the right nutrients. If they are sick, or very old, they have lost the ability to repel an insect attack with their own defensive chemical arsenal.

“Insects are great at sensing the health of the plants they evolved with,” he added. “They know if it’s stressed. When they take a chomp out of it, they determine if it’s something good to eat or not. Healthy plants for the most part are not. If you have a problem, try different plants. Try plants that grow in the region. When you bring in exotic plants, they may not make it in this soil or this climate. Plants evolved in different habitats, so know your soil and what it is going to take to give them a healthy environment.”

Olson noted there is no way to protect plants from bugs. They’re going to come, like it or not. If one has flowers, there will be various types of pollinators that come to visit. Some of the butterfly or moth visitors will like their new digs and fresh flowering cafés so much, they’ll leave a deposit for next year in the form of eggs.

Of course the eggs hatch into caterpillars, and we all know what voracious eaters they are. But, don’t kill those caterpillars because that will end the metamorphosis into one of those beautiful and amazing butterflies that keep your flowers pollinated, keeps the plant reseeding and keeps your garden full of blooms.

Mesquite is one plentiful bush in Southeastern Arizona. They are everywhere. But, they do not grow to any great height. Olson said that is due to the Mesquite Twig Girdler. The female of the species will cut around a twig on the end of a branch, so it dies. Then, she can lay her eggs, and the hatchlings will have something to eat. The girdler acts as a natural pruner.

“Everyone worries about the agave weevil. If a plant is sick, old and dying, it will lay its eggs in the foliage. They do not affect healthy plants. Just because you see one has been affected, it does not mean that all of them will,” Olson said.

Wood borers, too, get a bad rap, he explained. They tend to affect the lower, older, dying limbs of trees. Bark beetles seek out dead wood.

“If you see them, that’s why you see them. They are part of the natural scheme of things. They take out the weak and the sick,” he added.

Often, pesky insects have natural predators. Take the cute lady bug. In it’s larval stage it is a fierce predator that loves dining on other insect larva. Green Lace Wings also have a predator stage as larvae.

As for ants, the horned lizard has a hearty appetite for the little brown guys.

Spiders are also good predators, and Olson thinks they have an undeserved reputation just because they all have the capacity to bite when someone disturbs them.

When it comes to mosquitoes, one of the best ways to deal with them is to get rid of any standing water. Still, mosquitoes also provide a food source, both in the aquatic stage and in adult life.

Fish and many aquatic creatures live on the larvae swimming around in ponds. Birds and other insects eat them in the adult form.

Because mosquitoes evolved right along with humans, so did their tendency to carry the microscopic bugs that act as population control.

“What we have to remember is that insects evolved right along with vertebrates. Some evolved into blood eaters, like mosquitoes and flies. As populations of humans tended to congregate in localized areas, the frequency of deadly illnesses increased. When the flea,  mosquito or fly bites, it gathers the bacteria from the blood and then becomes a method of delivery of disease,” he emphasized. “It’s natural population control.”

Olson says people should enjoy the show of the natural world.

“Enjoy, don’t fear this fantastic display by the insects. Nature is a wonder, always, if one can just rekindle the interest and enthusiasm for all kinds of life, not just the sterile paranoia that seems to exist in the asphalt neighborhoods of today ... These insects represent wildlife that is extremely important to the success and survival of the Sonoran Desert.”

Herald/Review reporter Shar Porier can be reached at 515-4692 or by e-mail at shar.porier@bisbeereview.net.