Natural Insect Control – Maintain and Grow a Healthy Garden

Planning and organizing where your flowers and vegetable seeds will go is a big step in your gardening, you will also want to be sure your garden remains healthy and beautiful all season through.

The following tips can be followed for natural insect control and include; the knowledge that healthy plants attract fewer insects; using healthy soil, you will always want to be building your soil by using organic fertilizers, composting and mulching; making sure your garden is free of debris and weeds (breeding grounds for insects), weeds also complete with your plants for nutrients and water; and always thoroughly cleaning your tools in the fall or after dealing with diseased plants as to not spread any potential problems.

Bad insects and the bugs that eat them

The next time you’re tempted to swat an insect you find in your garden, first make sure it’s a bad insect and not one of the good guys. Here’s the difference between the two:

A bad insect is any insect that, through its feeding activities, injures or destroys a plant. Good guys are the ones that feed on the bad, reducing the potential damage that can be inflicted by the bad ones.

Aphids, tomato horn worms, cutworms, snails and slugs, corn earworms, spider mites, whiteflies and thrips are some of the bad guys. (Snails and slugs are mollusks, not insects, and spider mites are true spiders.)

How to Get Rid of Garden Insects

Your garden allies include the lady bird beetle (also known as the ladybug), triphid fly, the syrphid fly larvae, the green lace wing, aphid lion, pirate bugs, wasps and the assassin bug. Aphids make up the largest number of living insects found anywhere in the world. Aphids go after roses, fruit trees, artichokes, beans, cabbage and lettuce.

Infestation is promoted by new or rapid growth of plants. Aphids consume plant fluids. They damage the reproductive capacity of a plant, distort the foliage and, because they carry plant diseases, pose a threat in this fashion, too. Aphids are, in a sense, big, juicy couch potatoes. You almost feel sorry for them because they are slow moving, are without benefit of defensive weaponry and are prey to both predators and parasites.

Ants protect aphids like farmers protect cattle. Ants want the honeydew aphids produce and transport it to the ant colony where it is used almost immediately. In a process called herding, ants will carry aphids to a location that’s more convenient for the ant colony’s activities. If you see ants going up a tree you can be almost sure there are aphids in the tree. Just follow the ant trail.

One of the biggest threats to aphids are aphid lions, the offspring of a beautiful insect named the green lace wing. Aphid lions are voracious feeders with protruding mandibles it uses to pierce the aphid, drain body liquids from the aphid and then toss it aside, all in 30 seconds or less. How do aphids react to aphid lions wandering among them, consuming one aphid after another?

The aphids do nothing. Picture a scene in which you have a multitude of aphids, and in that multitude you have a predator feeding on the aphids, chomping their way through, tossing dead aphids aside, without any disturbance of or disagreement on the part of the aphids. In short, the aphids tolerate the presence of this insect without showing fear or concern. As the aphid lions consume one aphid, they may be looking out of the corner of their eye for the next victim, but the aphids just go about their business.

There are several chemical treatments for aphids but caution: don’t treat if ladybugs or aphid lions (lacewing larvae) are present; instead, pinch off or prune affected parts. Washing foliage during watering will also reduce aphid populations. Monitor with yellow adhesive strips.

The syrphid fly larvae also eats aphids, as well as mealy bugs and scale insects. This larvae is the offspring of hover flies that resemble wasps. The flies deposit their eggs in aphid colonies.

Tomato horn worm

The tomato horn worm is another big monster associated with garden life but the female picanted wasp implants 15 to 20 eggs in the host victim and after hatching feed on the insides of the horn worm. They feed for 15 to 20 days but they take the utmost care not to damage the organs that sustain the worm’s life. That sustains the worm right up to the last moment when it is shriveled up, about ready to die (if not already dead) and before it does the predator bores a hole, crawls out and, as if to take one last parasitic swipe at the host, pupates on the host skin so it can metamorphose into an adult wasp.

The tricoderma wasp is another incredibly efficient beneficial creature in the garden. It’s very small it requires magnification to see it and it feeds on a range of more than 250 insects.

Snails and slugs

Snails and slugs are probably one of the most omnivorous of all creatures. They eat just about any kind of plant material, fresh or old, organic or inorganic, but they do have a strong liking for young, developing plants. Their appetite is almost without limits.

Birds, raccoons and skunks are fond of escargot. Humans aren’t and have tried everything from cooking oil, beer, wine, potash, ashes and a whole gallery of recommendations to try to eliminate snails and slugs but copper barriers seem to remain an efficient snail control. Mucous on the skin surface of snails and mollusks reacts with copper in a manner they find unpleasant. Oil, wine and beer sounds good, but doesn’t prove effective.

Also effective is the garden practice of clean culture eliminating trash from around the base of plants. Clean culture is the most effective approach. Snail bait is also effective. Another weapon against snails is the often-used bottom of the shoe. Snails need sheltered, moist areas and you seldom see them in the open unless they are moving from one spot to another.

Corn earworms

Corn earworms feed on the ear tip of sweet corn and early ripening crops are less affected than than later plantings. They have voracious appetites and do considerable damage, much of it cosmetic, often to the point where people don’t want to eat the corn.

As a general rule if you plant corn from early May to June, the crop is largely free, not entirely (10 to 15 infestation rate); If you plant in June, the infestation rate may go to 30 to 40 percent, and a July planting may have close to a 100 percent infestation.

Attempts at natural controls yield little in the way of satisfying results and chemical control is expensive and time consuming. That’s why this insect is so troublesome.


Cutworms do their dirty work at night and hide out during the day. If you plant seeds, you have to be concerned about the leaves and stems. If you plant marigolds, they will eat the whole thing because this little guy adores young seedling plants. They are called cutworms because they can cut a plant right down to the ground. More than one gardener has gone to sleep with a marigold or two in the garden and awakened to to find them all gone. They literally make a marigold plant disappear.

Other bad characters in the garden are spider mites, white flies, and thrips.

Spider mites

Spider mites are one of the most common enemies and are a danger to such tree crops as apple, pear, peaces and walnut. A single leaf may hold 200 to 300 of them, all sucking the juice (and life) out of a tree. If they don’t defoliate a tree, they can come close. Pesticides in combination with natural predators is the best control. Kelthane and Averticem are the commercial choice.


Whiteflies infect cabbage, broccoli, cauliflower, fuchsias and miscellaneous weeds and ash trees. If you raise any of those vegetables or flowers in a greenhouse introduce the whitefly’s natural enemy, Encarsia formosa, a parasite wasp. It feeds on plant sap, absorbed through the leaf. Orthene is one chemical can be used on whiteflies.


Thrips have a nasty habit of boring into developing rose buds before the buds pop open. By the time the bud does open, the thrip has left its graffiti in the form of distorted, disfigured leaves. There are no natural controls other than one recently discovered enemy. The recent find: another thrip, the pirate bug, that likes to feed on other thrips.

One of the more beneficial insects and a very pretty one, too is the lady bird beetle. That little insect, which measures about a quarter of an inch, single-wingedly in the late 1800 took on the mealy bug, defeated it and saved the California citrus industry. The lady bird beetle and its larval offspring both feed on harmful creatures and they’re not fussy what is on the menu.

A lovely flower or vegetable seeds garden is the result of a bit of hard work and planning but certainly worth all the enjoyment to be found all season long.

One final note:

you can sleep well tonight knowing that birds, spiders, dragonflies, beetles, parasitic wasps, predatory wasps, bugs and bats are out there on 24-hour patrol in an effort to maintain a balance between good and bad insects.