Ugh! is the most common reaction to the appearance of a bug. And by "bug," I mean an insect or spider. Most people instinctively dislike these tiny creatures, and in some cases are pathologically afraid of them.
But there are many species that are beneficial to the gardener and to the environment and should be actively encouraged and cherished for their good works.
Beneficial bugs can be divided into categories based on their works: pollinators, parasitoids or predators.
One of the best-known pollinators is the bee, and with the current dangers from colony collapse and the decline of the honey bee, other bees are very important in the garden and with farm crops.
Bumble bees, sweat bees, mining bees, yellowjackets and wasps all help pollination as they move pollen from the male anthers of a flower to the female stigma and accomplish fertilization. Each kind of bee does this in a slightly different way, and some of them have less endearing habits as well, but they are all important to us.
Butterflies and moths also are pollinators, as are thrips, some beetles, carrion flies, fruit flies and midges.
Among predators, the spotted lady bug is an omniverous consumer of aphids. The syrphid flies look somewhat like small bees and also eat aphids in great quantities.
A robber fly will snag its prey in the air, eating Japanese beetles and flies. The minute pirate bug (shown) does its part by eating tiny pests such as leaf-hoppers, while the praying mantis and assassin bug will consume any other insects that get in their way.
Parasitoids are parasites that eventually kill and usually eat their targets, laying eggs on (or in) another insect, and the larvae that hatch feed on the prey until they kill it. Examples of parasitoids are tachinis flies, which look like house flies but lay their eggs on squash bugs.
Many species of wasps act this way as well. The sight of a tomato worm with little white eggs sticking all over it is a good sign for the garden grower whose tomatoes are being attacked by this fearsome worm.
To attract these beneficial insects into your garden, you need to provide plants that have plentiful nectar and pollen, year-round shelter and a habitat that is free from insecticide. I try to do this, but am driven to sprinkle a little Sevin on my roses and ornamental cherry tree in years when the Japanese beetles arrive in large quantities. Fortunately, the last few years my plants have been lightly infested with these nasty pests and picking them off has sufficed.
Some good plant families to grow are the carrot family, which includes dill, parsley, cilantro and many more herbs, the aster family with feverfew, sunflowers and Shasta daisies and the mint family. If your roses get infestations of aphids, be sure to grow some of these in the immediate area.
You will find offers of beneficial insects that can be mailed to you and released in the garden, but this is a risky business because you have no control over where they go from there. I have a lady bug shelter which came with some attractant to paint on, but although it does draw a few, I don't think it is very effective. It does look nice in the herb bed, though.
There you have it. Don't automatically shudder and swat when you see an insect; it may be a predator, parasitoid or pollinator. On the other hand, when you spot a slug ...
Janet Del Turco is a local gardener and a graduate of the Ohio State University Master Gardener program. Contact her at firstname.lastname@example.org.