By MIKE STAHLBERG The Register-Guard

THEY'RE TINY but bloodthirsty, these backcountry terrors that thrive on sneak attacks.

They, of course, are mosquitoes. And the near-record snowfall in the Oregon Cascades last winter is a sure sign that the biting bugs will be out in force this summer.

Which means it's time for a heart-to-heart talk about campland security, about how to defend yourself and your loved ones against marauding mosquitoes.

In pioneer days, there were only a handful of choices: 1) Slap and swat at them; 2) Slather bear grease over your face, neck and hands; 3) Cower in the smoke of a smoldering camp fire; or 4) Run!

But this is the 21st century, and the array of weaponry at our disposal in the battle against mosquitoes is now almost mind-boggling.

High-tech weapons range from propane-powered mosquito traps to electronic bug zappers to sonic repellers designed to frighten mosquitoes away by emitting sound frequencies that mimic the dragonfly, the mosquito's arch enemy.

At the other end of the technological spectrum are herbal options such as garlic and catnip - subject of the latest and loudest 'buzz' in insect repellents.

In the middle are the old mechanical and chemical standbys familiar to any veteran of the war against mosquitoes - netting and myriad oils, lotions and sprays designed to ward off insects.

Most of the latter include N, N-Diethy-meta-toluamide, commonly known as deet, consistently proven to be the compound most effective in discouraging mosquitoes from landing on exposed skin.

That, however, could be changing, if some early research into catnip oil is any indication.

Catnip, a perennial that is actually a member of the mint family, leapt on to the insecticide stage last August at the 222nd national meeting of the American Chemical Society, the world's largest scientific society.

An Iowa State University research group presented a paper that compared the mosquito-repelling qualities of catnip oil, called nepetalactone, with deet, the 'active ingredient' in countless commercial insect repellents.

Entomologists Chris Peterson and Joel Coats reported that the essential oil in catnip was about 10 times more effective at repelling mosquitoes than deet.

Their research involved placing groups of 20 mosquitoes in two-foot long glass tubes. One half of the inside of the tube was coated with a chemical compound; the other half was left untreated.

In tests with catnip oil, only 20 to 25 percent of the mosquitoes remained on the treated side of the tube after 10 minutes. When the same tests were conducted with deet, 40 to 45 percent of the mosquitoes remained on the treated side.

Furthermore, catnip oil diluted to one-tenth strength had the same effect as full-strength deet. That led to the claim that nepetalactone is 10 times as effective as deet.

The experiments were conducted using Aedes aegypti (the so-called yellow fever mosquito), one of about 170 species of mosquitoes found in North America. However, Peterson told Science Daily magazine that nepetalactone should work against all varieties of mosquito.

'Our lab tests show the essential oil of catnip would be effective in repelling mosquitoes when sprayed on clothing or mosquito netting,' Coats said. 'We think it would also be effective if rubbed on your skin, but we haven't actually done that test yet.'

Scientific research on human subjects is no doubt now being conducted by commercial insecticide companies, who have yet to market a catnip-based repellent.

But Alice Doyle and Greg Lee, partners in Log House Plants nursery near Cottage. Grove, say they conducted their own catnip experiment and were so impressed with the results that they began growing 'hundreds and hundreds' of flats of the plant.

The catnip - along with posters touting the plant's mosquito-repelling properties will be distributed to the -nursery's retail customers in mid-August, Doyle said.

Doyle and Lee live near Dorena Lake, and Doyle said the mosquitoes there are often so thick that they have to put on a coat for protection when they run out to their garden to pick a few ears of fresh corn for dinner.

After hearing about the Iowa State research last September, Doyle said, 'we rubbed catnip leaves on one arm and left the other arm bare' when they went out to the garden. They returned with a dozen ears of corn and mosquito bites on the untreated arms, but no bites on the arms that had been rubbed with catnip.

'We're convinced,' said Doyle, who likes the fact that 'this is a natural thing that people can do themselves, versus deet, which is very suspect (The Annals of Internal Medicine noted in a 1998 review that deet, while possessing a 'remarkable safety profile during more than 40 years of use by millions of people worldwide,' has been associated with a small number of severe reactions in some people, including seizures and death.)

Another unlikely organic option that is relatively new on the market is sold under the brand name Mosquito Barrier. It is simply very strong liquid garlic diluted in water. Mosquito Barrier, . however, is not intended for application to skin.

Rather, it is meant to be sprayed on lawns, plants and trees in yards, parks and golf courses. The manufacturer claims that Mosquito Barrier not only kills adult mosquitoes on contact, but keeps new mosquitoes from moving into the area for four weeks or longer.

While the garlic odor disappears in 30 to 60 minutes as far as the human nose is concerned, mosquitoes, ticks and fleas can detect the repulsive (to them) natural sulfur for weeks, the manufacturer says. -

Perhaps we shouldn't be surprised that people are turning to plants for insect relief.

After all, citronella - the primary alternative to deet for many years - is a natural oil extracted from an Asian grass. It is used in everything from candles to Skeeter Defeater brand soap.

And an Oregon-made mosquito repellent on the market since 1997 is made of soybean oil, geranium oil and coconut oil. Known as Bite Blocker (produced by Consep, Inc., of Bend), it was found to be more effective than a 6.6 percent deet-based spray, even 3 1/2 hours after application, according to a study conducted at the University of Guelph in Ontario and reported in the Annals of Internal Medicine.

Also, one of the most lethal (to mosquitoes) products on the market is permethrin, a man-made version of a chemical originally derived from the crushed and dried flowers of chrysanthemums.

Permethrin does not repel insects. It kills them on contact by causing nervous-system toxicity. It, too, is not for use on the skin. Rather, it is sprayed on clothing, tents, sleeping bags and the like, where tests show it maintains its potency for at least two weeks.

Several products containing 0.5 percent permethrin are on the market, including Repel Permanone.

For bare skin, deet remains the most effective and long-lasting protection, according to the Consumers Union, which reported on its tests in the June, 2000 issue of Consumer Reports.

CU put several commercial insect repellents - including Natrapel, a citronella product, and Bite Blocker and others that use plant oils instead of deet - to the ultimate challenge. The human testers stuck their arms, coated with various products, into glass boxes containing 200 hungry mosquitoes of three different species. Researchers counted the number of hugs that bit during thee minutes. If none bit, the tester waited a half-hour and re-offered his or her arm again. The procedure was repeated every half-hour until at least one mosquito bit during successive exposures. -

Consumer Reports identified the two most effective repellents as Amway HourCuardl2 - a cream that's 33 percent deet - and Ofti Deep Woods for Sportsmen, a pump spray that is 100 percent deet. Both kept mosquitoes away for 11 or 12 hours. Amway no longer sells HourGuardl2, but Consumer Reports said the same formulation is also marketed as 3M Ultrathon (after the product's maker, the 3M company, which also provides it directly to the U.S. armed forces.)

As for the non-deet products, Consumer Reports said 'only the soybean oil of Bite Blocker offered any mosquito protection worth noting - one to four hours. ' Natrapel 'did very little to repel mosquitoes,' the magazine said, and Avon Skin-So-Soft with citronella 'did not protect our testers: mosquitoes bit their arms at the earliest opportunity.'

The magazine, of course, did not test catnip oil or garlic juice.

Many people, of course, would prefer not to have to put repellents of any sort on their. skin. For many others, mosquitoes are annoying even if they don't land and bite. They still buzz too close to eyes and ears for comfort.

For those people, the claims made by makers of various scent-free gadgets designed to drive mosquitoes out of the area sound awfully appealing.

The Web site No-mosquitoes.com, for example, offers a trio of "Mosquito Control" devices (including one that you wear like a wrist watch). The company claims the battery-powered devices emit sounds, barely audible to the human ear, that mosquitoes intensely dislike. Among them: the sound frequency emitted by the dragonfly, a mosquito predator. The desktop version of the device, which sells for $21.95, claims to create a 16-foot by 16-foot mosquito-free zone.

A different approach was taken by Coleman Company Inc., the camping equipment giant. Rather than trying to drive mosquitoes away, Coleman decided to lure them in - so they could be trapped and killed. Coleman claimed 'Revolutionary Technology' back in April when it introduced its Mosquito Deleto system, which it said would 'give consumers an easy approach to getting rid of mosquitoes where it matters most - on decks, patios, backyards and on camping vacations.'

The propane-powered Mosquito Deleto Trap emits a combination of heat, a 'special scent' and carbon dioxide. 'The mosquitoes are fooled into thinking the trap is a person or an animal,' Coleman said in announcing the new product. 'Once mm-ed to the trap, mosquitoes become caught on the adhesive cartridge, where they die.' The device sells for $170 to $200.

Unfortunately, some of the early models aren't as effective as people had hoped. The Coleman Company had to recall about 136,000 Mosquito Deleto Traps (model numbers 2950-800 and 2950-801) just at the height of the mosquito season because the propane regulator on the units can leak or allow an overflow of propane gas, posing a fire hazard. 'Coleman has received 28 reports of traps melting or catching on fire as a result of propane leaking,' the company said in its recall announcement.

Article from The Eugene Register-Guard, July 25, 2002