Ugly doesn't necessarily mean bad, especially when it comes to lawn and garden insects.
Gardeners who reach for the pesticide every time they see a large, ugly, hairy insect on their prized tomato plant may be doing more harm than good. The insects that pesticides kill may be allies, not enemies."People need to recognize that the majority of the critters in the garden aren't harmful," says Larry Caplan, Indiana extension service educator for horticulture. "Only a small percentage of the insects that fly around the yard are harmful to plants."
In fact, rather than being harmful to garden plants, many garden insects, including some of the ugliest ones, cannibalize, poison or suck the life out of the harmful insects.
"They are the Tyrannosaurus Rexes of insect world," says California gardener and illustrator Allison Starcher, who has written "Good Bugs for Your Garden."
You will have a better chance of controlling the harmful bugs if you show more patience and let your allies help, according to Tom Turpin, Purdue University professor of entomology.
"If you don't have an itchy trigger on the spray can, in some instances you may be able to biologically control the agent that shows up," Turpin says. "If you let the natural control begin to take over, you will end up with season-long control."
But once you begin to spray and destroy the cycle of the helpful insects, you may have to keep spraying all season long, he said.
A braconid wasp, which has a wingspan of less than half an inch, is one of the best controls for the destructive tomato hornworm. The tiny black or brown wasps, which look like flying ants, lay their eggs in the hornworm. The immature wasps feed on the inside of the hornworm larvae and then emerge and spin a cocoon on the back of the hornworm. The wasps emerge from those cocoons to eat more hornworms.
"I've seen people spray the worms which had the cocoons of the wasp on the side," Turpin says. "They killed the wasps with the worm."
Miss Starcher noticed the beneficial bugs when she began taking a microscopic look at garden insects to help with her illustrations for a garden newsletter.
Her first impulse was to grab the insecticide when she saw aphids on her roses.
"But I looked closer and saw this alligator-shaped creature eating the aphid," she says. "It turned out to be a ladybug larvae."
On the same rosebud, Miss Starcher spotted a green bug that looked like a caterpillar.
"I thought, 'Oh! I've got to kill this one,"' she adds. "Then I noticed it had an aphid raised above it and it was sucking the life out. I learned it was a hover fly larvae."
Another predator of aphids is the aphidiid wasp, which deposits eggs in the aphid. After the wasps hatch they feed on the aphid, eventually killing it and leaving a brown mummified case.
"Now I don't panic when I see aphids when I see the mummy cases," says Miss Starcher. "If I see the mummies and the larvae, then I know if I wait a week the aphids will be gone and I will have helped to reproduce more good insects in my garden."
Miss Starcher said she also moves the beneficial insects around the garden as needed.
"I've moved the ladybug larvae to a plant I want to help out," she said.
Miss Starcher said the idea for the book came when she began doing research to augment what she could see in the garden.
Now the strongest insecticide she uses is a dishwashing soap. If necessary, she picks some of the "bad" insects off the plants.
She also sets beer traps for slugs. She buries a small bowl so that its lip is level with the ground and fills it with beer. By morning slugs fill the dish.
Sometimes she buys beneficial insects to help out in her garden.
She advises gardeners to plan well in advance.
"If you know every year you get an infestation of aphids about a certain time, you can order the ladybugs about that time," she said.
Purchased ladybugs have a habit of flying off when released, Miss Starcher warns. She suggests dampening the plant, releasing the bugs just before sunup or after sundown, and gently laying handfuls of the bugs at the base of infested plants.
Other beneficial insects Miss Starcher describes include damselflies, dragonflies and praying mantises.
In addition to the ladybugs (she calls them ladybird beetles), there are other beneficial beetles which aren't as attractive: blue-black or dark brown ground beetles, such as cutworms, snails and slugs, and tiger beetles, which vary from bronze to blue and eat ants, small beetles, caterpillars, aphids and grasshoppers.
Many garden flies, besides pollinating flowers, are voracious eaters of insects in their larval stage. Hover fly maggots can eat one aphid a minute, Miss Starcher says.
The robber flies catch flies, bees, beetles and grasshoppers, while the tachnid flies prey on caterpillars, beetles, sawflies and green stink bugs.
Miss Starcher also praises green and brown lacewings, spined soldier bugs, thrips and big-eyed bugs.
Miss Starcher has become less particular about how her garden looks.
"I don't mind a hole in a leaf, and I'm less picky about everything being perfect," she says. "I'm more interested in keeping things on a nice level.
"This adds a dimension to gardening."
(Linda Negro is a reporter at The Evansville (Ind.) Courier.)