SPECIAL ISSUE: SPRING HOME & GARDEN GUIDE : Moths Very Efficient at Planting Worms on Your Tomatoes

Times Staff Writer

Most everybody who has grown tomatoes has seen those worms.

Huge, green ones with upholstered hides and a large hook at the end. The “tomato worm,” which is really the tobacco hornworm, turns up uncannily in a vegetable patch just as the plants are taking off.

If a gardener isn’t quick to stop them, they can eat vast quantities of buds and foliage, leaving the tomato plants looking like the skeleton of a grape bunch: a sea of tiny stumps.

The best way to halt them is simple: “You pretty much just pick them off by hand,” since there are usually not many of them, says Mark Nestor of the University of California Cooperative Extension office in Anaheim. The pesticide carbaryl, marketed as Sevin, and the bacterial agent Dipel can also be used on plants to kill the worms.


But how do these little monsters even know that you are growing tomatoes?

Well, they don’t. But their parents do. The worms are the pupa stage of the hornworm, which becomes the sphinx moth when it grows up. A sneaky pest, the moth sniffs out tomato plants during the night hours and deposits eggs in the soil, much like tiny time bombs waiting to emerge and decimate your crop.

“They’re very efficient at finding their food source,” says Nick Nisson, entomologist for the Orange County commissioner of agriculture. In a glass case in Nisson’s Anaheim office is a preserved, mature sphinx moth. It is just as well that the rascals are nocturnal; these things are BIG and ugly, with 4-inch wingspans. And you thought the worms were gross.

Nisson, whose job is to identify and monitor insect species that may threaten the county’s agricultural industry, takes a rather benign view of the thriving world of creepies and crawlies.


“Most things aren’t worth worrying about,” Nisson says. “There is an attitude that every insect you see in the garden is bad. But many are innocuous or even beneficial.”

This means it is not always necessary to use pesticides when preparing your garden plot in the spring. The soil should be turned and examined for eggs or grubs, and if there are none, you are home free. At least at the start.

Ladybugs are among the good guys. They feed on aphids and other little menaces. Predacious mites also eat other bugs, as do green lacewings and even earwigs, which also help clean up garden floors by consuming old foliage.

Earwigs, which come in several varieties, the most prevalent being the European type, are about an inch long, reddish brown to brown or black and have wings under short, hard covers and a pair of pincers in the rear. The latter are quite formidable and can put a dent in a finger or toe if the insect is provoked.

How do you provoke an earwig? Well, you could start by bringing up that old European myth about them crawling into people’s ears at night, which is where they got their name. An updated version of that was in an episode of Rod Serling’s “Night Gallery” TV show in which the villain survives an earwig’s journey through his head, ear to ear, only to find out that it was female--and laid eggs! Eyaaaahhhhhh!

For the record, earwigs are essentially harmless, other than the occasional nip. Sometimes delinquent earwigs, enraged at re-runs of old “Night Galleries,” are found consuming healthy plants, but who’s perfect?

Ants are also a mixed bag, according to Nisson. They help scavenge the garden floor, but “in most cases, the ants are not doing any good.”

This is mainly because the little gluttons are addicted to honey dew, the sweet, sticky emissions of aphids. As for aphids, they are those tiny insects that reproduce by the thousands, leaving a light green or black living film on the leaves of such vegetables as lettuce and spinach, which kind of takes the appeal out of your average garden salad. So fond of the honey dew are the ants that they actually prevent ladybugs and other guardians of the garden from doing their job of eating the aphids. In effect, the ants “farm” the aphids, moving them to safety at times, “so indirectly, the ants are a problem,” Nisson says.


Aphids can be cleaned off plants by shooting water on them with a hose, scraping them off or pelting them with a number of pesticides, according to UC Extension’s Mark Nestor.

Ants can be controlled with ant stakes and by directly spraying or powdering them with any number of pesticides.

Southern California has zillions of brown snails, courtesy of the French, who should have curbed their generosity right after donating the Statue of Liberty. Actually, it was just some misguided soul who brought the snails over in the mid-19th Century to breed them for restaurant use. Some of them got away. Now their descendants are laughing at les humans, who can’t seem to get them out of their yards and gardens.

But there are measures you can take, short of napalming your garden. You can harvest them, plop them into some cornmeal for 3 days to clean impurities out of their systems and then look up some good escargot recipes.

You can also launch a civil war by sowing decollate snails. A rather useful creature and one that the folks at the UC Cooperative Extension are recommending for pest control, the decollate snail is an inch-long native of the Mediterranean that feeds on the brown snail. It is available through three outlets in Southern California: Decollate Snails, Lake Arrowhead, (714) 337-2282; Foothill Agriculture Research Inc., Corona, (714) 371-0120, and J. Harold Mitchell Co., San Gabriel, (818) 287-1101.

Hand-picking brown snails and disposing of them in the trash after crushing them is one method of control suggested by UC’s Division of Agricultural Services. A more humane way, a sort of last hurrah mollusk-style, is to put out saucers of beer and let them crawl in and have a good snort before they expire.

If all else fails, there are a number of pesticides on the market that effectively control snails, although they must be reapplied every few weeks and can be quite hazardous to small children and pets. The snail bait also controls slugs, which are pretty much snails without the shells. We’re not sure where they came from, but it’s a good bet the French had nothing to do with them; without the shells, they’re hard to sell as an over-priced appetizer.

Another pest that is frequently found in gardens is the grub, a small, white, C-shaped worm with an orange-brown head and three pairs of legs. Grubs can do a lot of damage to the roots of vegetables before growing up to become “June bugs,” those Volkswagens of the air that lazily fly around a porch light until your 5-year-old takes a whiffle bat to them. The child, while displaying an unattractive streak of cruelty and disrespect for other living creatures, is not doing you any real big favor; the mayhem in your garden is caused by the grubs, not the adults.


The grubs, which start out as eggs laid by the adults (on second thought, keep swinging, kid!) go through several manifestations, getting closer to the top of the soil until they emerge in the spring to fly away in May and June. Hence the name June bugs (Mayflies had already hogged the May moniker, no doubt, when they named the June bugs).

The grubs can be controlled by getting rid of old mulch piles and by mixing pesticides such as chlorpyrifos and diazinon deep into the soil when one or more grubs per square foot are found. Some pesticide makers recommend treatment of the soil before planting, but the UC extension people say that soil can be examined in mid-to-late July for the grubs.

Other pests found in the garden are the little gray, armored pill bugs and sow bugs, which look very much alike and are not really insects at all but crustaceans, relatives of the crawfish and lobster. The sow bugs are larger than pill bugs and do not fold up like pill bugs can. Both can harm gardens by eating tender shoots. You can use pesticides but it is easier to discourage them by depriving them of dark, moist areas to breed in. If you do this, they will move on, maybe even to France.

The same goes for the green fruit beetle, a bright, shiny insect about an inch long. Eggs are laid in soil in the autumn just beneath organic matter such as lawn clippings, and the worm or grub is C-shaped, attaining a length of 2 inches in the spring. As soil warms in late May, the grubs move to the pupa stage, then emerge as beetles in July. The beetles are drawn to fruits and vegetables that are rotting, so, again, the best way to combat them is by keeping the garden clean. You can also attack the grubs by mixing diazinon into the soil.

For more information on battling pests or on any gardening question, the UC Extension Service has a telephone tip service that can be reached at (714) 447-7190.

Finally, in controlling pests, an ounce of prevention is worth a ton of cure. The most effective strategy for dealing with insects and snails is fourfold:

* Before planting, prepare the ground by removing dead foliage, boxes, boards, mulch piles, anything that might provide a breeding area.

* Identify the pests so you know what you are dealing with.

* Remove them by hand if possible or by using pesticides, always taking care to read the entire label--except for some “organic” powders, this isn’t kids’ stuff.

* Inspect your garden frequently so you can remove decomposing organic matter and nip infestations in the bud.

And when things start looking grim, remember: You are bigger and smarter than the pests. Humans have flown to the moon.

The pests have no business winning.