Wednesday, December 26, 2007

New ad for electronic pest control device from Riddex

Riddex has begun a new ad campaign (at least in our area) for their electronic pest control device called the Riddex Plus Digital Pest Repeller (tm). Since we get a lot of questions about these devices I thought it might be a good time to remind readers what the devices do, and don't do.

Marketers of electronic pest control devices (sometimes called ultrasonic pest control, or something similar) claim that these devices chase away insect pests and small rodents with electromagnetic and/or ultrasonic energy. They claim that laboratory tests have proven that the product works but they don't cite any actual studies. The only supporting documentation is testimonial.

Scientific studies

I could not find a single published study in any scientific journal that supports the use of electronic pest control devices for household pests like spiders, cockroaches, or rodents. Such a study would be inexpensive to conduct and could potentially add a great deal of credence to their claims. Instead the only evidence given by the marketers is testimonials in which users submit their personal experiences with the product. Personal endorsements, or testimonials, tend to be clouded with bias for a variety of reasons. Scientific trials on the other hand are designed to eliminate this bias as much as possible.

If you want to purchase one of these devices to test in your home here's a suggestion: since I could not find a published study, call the company and ask them to send you a citation from a supportive study. Then, if you get a citation to a scientific study that supports the use of electronic pest control devices please send it to me, and I'll post it here for others to see!

I'm not picking on Riddex in particular because none of these devices, from any manufacturer, has been shown to work. My guess is that proper trials have not been done because the manufacturers know that the data would not be favorable to their products. So, until scientific trials are done by reliable labs and the results published in peer-reviewed journals I'd suggest you avoid these devices. There are now safe alternatives to conventional pesticides for virtually all household insect pests, and rodents can be managed with traps.

I have posted additional information about electronic pest control devices in general at our 'Bugs site including a link to an FTC warning about these devices.

In summary, there is no good scientific evidence that any of these devices work. If there was good evidence you can be bet that it would be plastered all over their ads, but it is not.

Sunday, December 09, 2007

Hand lens - A Christmas gift for the gardener who has everything

Here's an idea for your Christmas gift list -- for the gardener who has everything (but I bet they don't have this!). It's not very expensive, every gardener needs one but very few have one and I can promise that this gift won't be returned. It's a hand lens or loupe.

A hand lens is a small, folding magnifying glass that gardeners and pest managers use to get a closeup view of pests and diseases. They are indispensable for accurate diagnosis of pests like spider mites, thrips and aphids as well as fungal diseases and leaf disorders.

A good quality, glass hand lens costs $10-$30 but will last a lifetime. Many gardeners attach their hand lens to a lanyard and hang it around their neck for quick access. For more information see our review of different types of hand lenses and how to use them.

Friday, August 03, 2007

Why are some yellowjacket wasp nests dangerous?

Yellowjacket wasps are social insects that live in large, highly organized colonies (left). Yellowjacket wasps construct nests made of papery material that are either suspended above ground (aerial nests, left) or buried below ground level (ground nests). Another social wasp, the paper wasp, builds smaller, less threatening nests.

Yellowjacket wasp nests may harbor thousands of individual worker wasps by late summer and early fall at the peak of activity.

Life cycle of a wasp nest

Nest construction begins in the spring when an inseminated queen emerges from winter hibernation. Nests start small but grow rapidly as new workers (sterile female daughters of the queen) are reared. Nests reach maximum size by late summer and early fall. As winter approaches new queens and a few male drones are produced. After these reproductives mate the males die and the newly-mated queens leave the nest. All of the current-year workers abandon the nest and die by the time cold weather settles in. Most yellowjacket nests therefore only last a single season.

What do wasps eat?

Almost all yellowjacket wasps capture live prey, mostly other insects, but a few species scavenge already dead animals or even plant material. Some yellowjackets seek the sweet, liquid honeydew produced by feeding aphids. Those species that will feed on dead animal tissue are called scavenger species and these are the ones that harass us during picnics or at other outdoor events.

Two scavenger species are the most common worldwide. Vespula vulgaris and V. germanica probably account for the greatest percentage of problems between these social wasps and humans. In the western US, western Canada and Hawaii, V. pensylvanica is commonly encountered in many areas and is extremely abundant in some areas. V. maculifrons is the dominant species in the mid-west, south and eastern US.

Defending their nests

Yellowjackets are highly defensive and can become quite aggressive when their nest is approached. Swarms of angry workers can be released from both aerial and ground nests if the nest is disturbed. Any vibration or loud, low-frequency noise, such as power lawn equipment, can provoke this swarming behavior.

Yellowjackets are most likely to be dangerous in late summer and early fall when their numbers peak. Ground nests are generally more dangerous than aerial nests because they are harder to see until you are literally standing on top of one.

How to destroy a threatening nest

Most wasp nests should be left alone. As predators wasps are considered to be beneficial insects in that they prey on many pest species. However, in late summer and fall a nest that is located near an area of human activity such as a garden, playground or picnic area may need to be destroyed to avoid the dangers of accidental contact.

If a threatening aerial or ground nest needs to be destroyed the safest approach is to use a Wasp & Hornet type spray (see link below for details) and treat the nest from a safe distance. Unfortunately none of the commercial traps are effective for destroying individual nests and poison baits are no longer available.

[safe ways of removing threatening nests]

Friday, July 27, 2007

Why are bed bugs returning?

Bed bugs are small (~1/4"), reddish-brown, oval, and wingless insects that bite to get a meal of blood much like a female mosquito. Unlike mosquitoes, all stages of bed bug, except the egg, feed on blood. Immature and adult bed bugs are similar in appearance, except of course for size. We humans are the bed bug's favorite host.

Bed bugs bite their sleeping hosts at night. Bed bug bites are painless at first but soon a red, swollen area develops that resembles a really bad mosquito bite. Unlike mosquitoes, bed bugs don't transmit any diseases but the bites can result in both itchy lesions and secondary skin infections.

In recent years bed bugs have started popping up in places where they had not been seen in decades. People staying at otherwise clean, well-managed hotels and motels are reporting bed bug bites. What's going on here?

A little bed bug history

Bed bugs and people have been together for a long time. A closely related species called the bat bug feeds on bats in caves and it is possible the bed bug adapted to our early ancestors when we used caves as shelter. Bed bugs have been our nearly constant bedtime companion ever since. After all, the admonishment to children on their way to bed of "don't let the bed bugs bite!" speaks to just how common bed bugs were at one time.

All this cavorting with bed bugs changed following World War II with the widespread use of synthetic pesticides like DDT and chlorpyrifos. These compounds were so effective and long lasting that many household pests, including bed bugs, virtually disappeared. Motel/hotel rooms were routinely sprayed or fumigated for cockroaches, bed bugs and other pests that might disturb guests.

Unfortunately these same chlorinated pesticides are also toxic to us, and environmentally damaging as well. They can be especially hazardous to children. Because of this, many of the most effective and long-lasting pesticides have now been banned or severely restricted and can no longer be used.

This is good news for our old friend the bed bug. Since rooms are no longer treated with highly persistent pesticides the door is open for bed bugs to move back in. All motel and hotel managers need to be vigilant and be prepared to act quickly when bed bugs are reported. Bed bugs are manageable with the lower toxicity materials available today but too often the problem is ignored because of the potential for bad publicity.

Can I check my room for bed bugs?

Bed bugs leave two distinctive "calling cards" that you can learn to detect. Bed bugs hide during the day in the folds of mattresses, around the bed in furnishings (bedside tables, picture frames, etc.), in loose wall coverings, etc. Check these areas as best you can for bed bugs and bed bug droppings when you first move into the room. Droppings are dark specks of fecal material that accumulate wherever bed bugs hide. Any evidence of bed bugs should be reported immediately to the front desk and you should ask for a new room. Don't get carried away with this inspection. Most rooms don't harbor bed bugs but a quick look around won't hurt.

The second calling card left by bed bugs is a distinctive room odor produced by the bugs themselves. The odor is sometimes described as "sickly sweet" or even that of fresh raspberry. The odor will probably only be detectable in a heavily infested room. Any sweet odor should be investigated.

Are there alternatives to toxic pesticides for bed bug control?

Rooms and bedding can be safely treated for bed bugs. It requires regular inspection and cleaning of mattresses, and furnishings around the bed, plus treatment of these areas with appropriate insecticides when necessary. New, low toxicity plant oil insecticides and inert dusts have replaced chlorinated pesticides for these applications. See this article for more details about bed bugs and their control.

Saturday, July 21, 2007

What's eating my rose bush?

Roses are one of the most popular cultivated plants for both gardeners and plant pests alike! Pests as different as aphids, black spot fungi and Japanese beetles conspire to steal this beauty from our landscapes.

You may decide to just let nature take its course in which case your roses will suffer some damage and may be weaker next year. Some gardeners, however, will decide to help nature along with a little gentle intervention. Here are suggestions for limiting pest damage while not resorting to harsh chemicals.

What you'll need:

  • 1 gallon garden sprayer; a smaller capacity sprayer will do if you have only a few rose bushes

  • fresh insecticidal soap concentrate; not household liquid soap!

  • neem oil or EcoPCO WPX botanical insecticide

  • Milky Spore microbial insecticide for soil dwelling white grubs

  • a fungicide that contains copper or sulfur, which may or may not be combined with soap

Use the garden sprayer to apply all of the garden chemicals. Insecticidal soap is a highly refined liquid soap that when used properly won't harm your plants. It is very effective against aphids, spider mites and other soft-bodied insect and mite pests. Don't use other household soaps, as some suggest, as these may actually damage or even kill plants.

Neem oil and EcoPCO WPX are both derived from natural plant oils and are effective against pests that chew on leaves like Japanese beetles. Both garden chemicals must be reapplied frequently (see label instructions), however, because they have limited residual activity (the time that an insecticide remains effective after application).

Fungicides inhibit growth of the fungi, or molds, that cause disease in plants. Black spot fungus is a common disease of roses and should be managed with copper or sulfur sprays.

Aphids are small insects that literally suck the life out of plants. They live in colonies on stems and leaves often covered by a sticky liquid "honeydew". Honeydew attracts ants and yellowjacket wasps. Aphids can be dark in color or light, greenish or yellow; "greenfly" is one common name, "plantlice" is another. Because aphid colonies grow so quickly they are often the rose grower's most important insect pest year after year.

Aphids are easy to control but most gardeners simply don't notice them until colonies are large and significant aesthetic damage has already been done. If damage is allowed to continue your rose bushes will become weak and won't be able to produce quality flowers.

Easy Aphid Control on Rose Bushes

As soon as you notice aphid colonies or honeydew do the following: wet entire plant with water from a garden hose; mix up a 2 percent solution of insecticidal soap (2 oz. / gallon); thoroughly spray entire plant with soap solution being careful to make contact with the undersides of leaves; wait 30 minutes then rinse plant with water from the garden hose. Repeat this procedure whenever you notice aphid colonies. The sooner you stop the infestation the better! A bonus - this treatment will also control spider mites just as well!

[more about aphids and aphid control]

Japanese beetles [picture of Japanese beetle] feed on the foliage of rose and many other landscape plants. Japanese beetle larvae, a type of white grub, also feed on roots causing twice the injury. While Japanese beetle does not occur everywhere, where it does occur it is a serious garden pest.

Protect Roots and Foliage from Beetle Damage!

Japanese beetles can be hand-picked off plants and dropped into a container of soapy water. Beetles can also be prevented from damaging foliage with timely applications of either neem oil or EcoPCO WPX botanical oil insecticide. Either insecticide will effectively stop feeding adult beetles from damaging your bushes.

Japanese beetle and other white grub larvae can be safely eliminated from the soil with a microbial (bacterial) insecticide called Milky Spore that targets only certain soil dwelling insect pests. Milky Spore bacteria may take several years to become completely effective so be diligent about adult beetle control as outlined above until then.

[more about rose pests]

Saturday, May 12, 2007

Timbor insecticide & wood preservative

I've gotten a number of questions this week about the insecticide Timbor. Rather than answer individual e-mails I decided to post a new page at our 'Bugs site about using Timbor for structural pests and to add a link here on the blog.

Timbor is made from sodium borate crystals (borax). Borates have many industrial uses in addition to their use as insecticides and fungicides.

Borate-based insecticides have been around for a long time. They act mostly as stomach poisons, which means they must be eaten to be effective, as opposed to contact insecticides which are absorbed through the insect's cuticle. In recent years a number of new borate products have been introduced as wood preservatives for dry-rot fungi and for structural pests like termites, carpenter ants and wood destroying beetles. Some products are liquids that contain a glycol base which is believed to help the borate penetrate further into wood fibers. Other products, like Timbor, are supplied as nearly pure borate powders which can be used dry or mixed with water.

For more information about Timbor take a look at is this article: [
Timbor]. The only real drawback to the borate insecticides is that they are water soluble so should only be used in relatively dry situations.

Friday, March 30, 2007

Spring is a good time for garden slugs and snails!

Springtime is when garden slugs and snails can be the most damaging to your garden and landscape. Slugs, and their shelled cousins snails, begin their feeding activity in spring when the weather warms enough so plants start putting out new, tender growth. Both critters feed by rasping at plants producing ragged holes and shredded leaves. Other evidence of slug or snail activity is slime trails. Slime is laid down as these mollusks glide over rough surfaces.

Believe it or not slugs and snails do mostly beneficial things for gardeners and the environment in general. They are important recyclers in many ecosystems by reducing bulk plant material into a size that decomposes more readily.

The problem is that slugs and snails don't distinguish between natural plant litter and our valuable garden and landscape plants. So, occasionally, we need to discourage this "recycling" activity.

Gardeners have generally used poison baits or traps to reduce slug and snail numbers. Traps use a yeast or bran-type component to attract slugs and snails. Traps work fine but they take daily servicing and can be messy. Poison baits are easier to use but pose some danger because of the toxic nature of these materials. Older baits that contain metaldehyde can be especially hazardous.

Recently, new, low toxicity baits have been introduced that significantly reduce the hazards of slug and snail bait. Look for iron phosphate as the active ingredient (poison) of these new baits. Iron phosphate is generally safe for use where pets or wildlife might have access to the baits and it breaks down to a type of fertilizer if not eaten by slugs or snails.

See the slug and snail articles at 'Bugs for additional information about these garden pests.

Sunday, March 18, 2007

Ticks and basset hounds

Our 1 year old basset hound Minnie is a tick "magnet". She goes for a walk everyday in a grassy/wooded area near our home and likes to check out all manner rodent holes and such. If we don't treat her with a flea and tick medication (see below) she comes home with ticks attached to her head or neck area. Spring and early summer are peak times where we live but others may see peak tick activity in mid to late summer.

Ticks (left) are related to spiders. Unlike spiders, however, ticks are ectoparasites of vertebrate animals. This means that they feed on the blood of animals ranging from snakes to mammals, including us and our pets. Like other blood-feeding invertebrates, for example mosquitoes, female ticks must get a blood meal in order to lay healthy eggs.

Also like mosquitoes, ticks can transmit some important human and pet diseases while feeding. Lyme Disease is spread by the bite of ticks as is Rocky Mountain Spotted Fever and many others. Not all ticks carry disease but since some do you should take appropriate precautions with all tick bites.

First, remove ticks as soon as they are found on yourself or your pets. The proper "tick-removal" technique is important to avoid secondary infection of the bite site. See the tick removal article at 'Bugs for our suggestions.

Second, use repellents when you venture into areas where ticks are common especially during hot, dry times of the year. Ticks prefer areas with tall, grassy vegetation. DEET or picaridin-containing repellents are very effective against ticks. For pets some of the topically-applied flea and tick control medications are effective as well. We now treat Minnie with Frontline Top Spot every two to three months during "tick season" which is pretty much all year here in Oregon.

See the tick articles at 'Bugs for more information.

Monday, March 12, 2007

Honey bees disappearing???

In some parts of the US honey bees are disappearing. During 2006 many beekeepers reported that the bees from some hives had simply disappeared. When opened the hives were empty and the bees were gone for no apparent reason. Researchers have subsequently determined that these die offs have occurred before but they are not yet able to assign a cause. Some believe it is a disease, some believe pesticides are involved. The condition has been named Colony Collapse Disorder.

European honey bee and pollen sac

European honey bee with pollen sac

Beekeepers and farmers who depend on bees to pollinate their crops (mostly tree fruits, nuts and some vegetables) are rightly concerned. In recent years bees and beekeepers have faced a number of new "pests". Varroa
mite and tracheal mite are ectoparasites that attack adult and larval bees. Foulbrood is an important disease of honey bees, and Africanized bees, the so called "killer bees", are taking over European honey bee hives in the southwestern US. All in all this is probably not the best time to start a beekeeping business in the US!

A task force has been formed by USDA and Penn. State University researchers. I'll post updates as the task force reports their findings.

"The Fumigator" -- Selecting A Good Exterminator

Where's John Goodmanwhen you need him??? (In case you missed it, John Goodman plays "The Fumigator", a bug exterminator, in the move Arachnophobia about spiders gone wild.)

Most people refer to companies that provide pest control services as "exterminators". Exterminators prefer "pest control operator" or "pest control technician".

By any name a good pest control company is like a good car mechanic -- when you need one, you really need one. While our main 'Bugs site is dedicated to helping you solve many household pest problems yourself, occasionally you'll need professional help. If you are having trouble deciding if you can do it yourself or if you need help take at look at this page.

We've posted some suggestions for screening pest control companies for those (hopefully few) times when you need one, and some additional things to watch out for.

Try to avoid the "maintenance treatment" trap. Some companies will push maintenance contracts that call for periodic (once-a-month, every three months, etc.) re-treatments. These repeated treatments are almost never necessary, especially not during winter months.

See the article at 'Bugs for more information.

Sunday, March 11, 2007

Drywood Termite & Fumigation

Termites are the only insects that are able to digest wood (actually cellulose, the "structural" part of wood). Most termite species require either relatively wet wood (dampwood termites) or contact with soil moisture (subterranean termites). One species, however, the drywood termites live in colonies that are constructed above ground in dry wood and need no contact with soil moisture.

Drywood termites live in warm climates, in both desert and coastal areas. In the US drywood termites are generally found in a band along the southern and coastal states on both coasts (red area in map below).

map of drywood termites in the US

red area = both subterranean and drywood
termites; green area = mainly subterranean

Damage from drywood termites can be extensive and is often hidden inside structural beams, flooring, etc. Because drywood termites lack connection to the soil they can be difficult to detect and treat.

Subterranean termites are usually controlled by treating the soil under and around structures with insecticide. Drywood termites, on the other hand, may require a very specialized and expensive procedure called fumigation (sometimes called "tent and fumigate").

For more about the biology and control of drywood termite see the pages at 'Bugs.

Thursday, March 08, 2007

Are natural insecticides always safe?

"A pesticide is a substance that disrupts or kills organisms that we consider to be pests, generally weeds, damaging insects, or microbes that cause disease. Natural pesticides are pesticides that are made by other organisms, usually for their own defense, or are derived from a natural source such as a mineral." from Natural Pesticides at

By this definition nicotine is a natural insecticide. Nicotine is produced by plants in the nightshade family of which tobacco is one species. Tobacco farmers have long-known that an infusion of water and tobacco leaves makes a powerful, and highly toxic, insecticide. Until recently nicotine was available as a commercial insecticide product called Black Leaf 40. Imidacloprid (Merit) is a modern insecticide based on nicotine chemistry.

chemical structure of nicotine
nicotine (drawing from wikipedia)

Nicotine is a powerful neurotoxin (nerve toxin). At low doses it acts as a stimulant while at higher doses it causes uncontrolled convulsions and respiratory failure.

Pyrethrum also is a natural insecticide. Pyrethrum is a product of certain plants in the genus Chrysantheum. It also is a powerful insecticide but is relatively non-toxic to other animals, including us. It is still widely used in products intended for homeowner use.

The point of the above is that calling something "natural" should not automatically imply it is safe. There are many natural compounds like nicotine that are highly toxic and you would not want to apply them around your home.

Insecticides are generally classified as organic (a product of a living organism), inorganic (usually mineral based like borate insecticides), or synthetic (manufactured). Organic insecticides can be further classified as plant-based or microbial. See this article for details about the different pesticide types.

Choose insecticides based on their toxicity and environmental persistence not on whether or not someone calls them "natural"; after all rattlesnake venom is natural, too!

Crane fly damage in lawns

Crane flies are medium to large insects that resemble large mosquitoes. In fact they are related to mosquitoes as both are "primitive flies"; delicate flies with long antennae. "Higher flies" like house flies tend to be heavier-bodied, stronger fliers with short, bristle-like antennae. Unlike mosquitoes, however, adult crane flies don't feed and are harmless. Crane fly larvae live in the soil and feed on plant roots.

Most crane fly species are confined to wet soils but a few have adapted to dryer soils which has allowed them to invade lawns and turf areas.

European crane fly

adult European crane fly

Crane fly life cycle

Crane fly eggs are laid in summer and larvae begin feeding on plant roots in fall. Larvae feed throughout winter and spring then pupate (pupae are the stage between larvae and adults) in early summer. Crane fly damage usually first appears during the dry days of summer as irregular patches. Grass dies because crane fly-damaged roots can't supply plants with water.

This brief life history points to two important periods when dealing with crane fly damage -- fall, when young larvae are starting to feed on roots, is the time to apply control measures, and mid-summer is when damage is likely to be seen.

For current crane fly control suggestions see our article at 'Bugs.

Wednesday, March 07, 2007

Put a barrier between you and dust mite allergen

Dust mites feed on the organic part of house dust (often, mostly skin flakes from us!) and then excrete an allergen, a substance that causes an allergic reaction, that can stuff up our nose or even lead to life-threatening asthma. Even if you could eliminate all dust mites, which is unlikely, their allergens would remain in bedding, carpets and other fabrics where dust mites live. When these fabrics are disturbed they release allergens into the air.

One of the best ways to prevent an allergic reaction to dust mite allergen is to put a barrier between you and the allergen, especially at night. If the allergen never gets airborne, it can't end up in your nose!

Since mattresses and pillows are a prime source of dust mites and dust mite allergen one solution is to cover them in special fabric that separates you from the allergens. Until recently these fabrics were made of plastic and tended to be very uncomfortable. Newer microfiber materials are more "cotton sheet-like".

See more suggestions for dealing with house dust mites at 'Bugs.

Friday, March 02, 2007

Insects that eat dirt - white grubs and lawns

White grub is the common name for larvae of scarab beetles like Japanese beetle, chafers and May/June beetles. White grubs feed on roots of grasses and can do considerable damage to turf grass. Because white grub larvae consume dirt along with plant roots their digestive track (visible from the outside) is usually packed at the back end with soil particles (see photo below).

White Grub Larva Photo by Steven Katovich,
USDA Forest Service,

Professional turf managers, like golf course superintendents, generally use conventional insecticides such as imidacloprid to manage white grub populations. Homeowners can use less toxic materials because their tolerance for white grub damage is usually higher. Milky spore (milky disease) and entomopathogenic nematodes are two least-toxic choices.

See this article about biology and control of white grubs for additional information.

Tuesday, February 13, 2007

House inspections for water damage & insects

Regular inspections of the exterior and interior of your house are one of the best ways to protect your investment and avoid costly repairs. Basic home inspections can be done by homeowners themselves and don't take very long to complete. Inspections should be done at least twice a year, once in winter and once in summer.

The summer inspection should be done early in the day to avoid the heat of the afternoon when pest insects may go into hiding. Slowly walk around the exterior. Look for evidence of insect activity on the siding and especially the area where the siding overlaps the foundation. If you find large ants "trailing" into or out of the house capture a few for identification. Also check under the house, if possible, for termite and powderpost beetle activity.

Anyone who has watched the TV show "This Old House" knows that water damage is far more important than insect damage in most situations. Winter is the best time to inspect for water and moisture problems. Again, walk slowly around the structure and look for water wicking up the foundation from saturated soil. Overflowing gutters are another source of water damage. Also, check structural wood for evidence of dry rot and mold damage (this can be done during the summer inspection as well).

Keep notes from all your inspections so you'll have a record of when the last inspection was done and what you found. See the home inspection pages at 'Bugs for more information and a form to help with keeping records.

Saturday, February 10, 2007

Garden Books for 2007

Rodale just published this update for the 2007 season. This excellent resource covers insects, diseases and weeds in an encyclopedic style.

Rodale's Vegetable Garden Problem Solver

Late winter spider mites and spruce aphids

With spring still a month or so off most people are not yet thinking about landscape and garden pests. However, there are two pests that occur on conifers (evergreen trees and shrubs that bear cones such as pine, fir, and spruce and arbovitae) that deserve your attention before spring weather arrives.

Spruce spider mite, Oligonychus ununguis, is the most important spider mite pest of conifers and can severely damage some host plants. If, for example, you've ever seen an Alberta spruce with large patches of dead needles the damage was likely done by spruce spider mites. Spruce spider mite is especially common and damaging on conifers that are drought stressed or, ironically, water logged.

Spruce spider mite spends the winter months as a small reddish egg (below) on branches and needles. These eggs hatch in early spring to become the first generation of plant damaging mites. Look carefully with your hand lens in late winter and you'll see the eggs on infested plants. If you find eggs late winter is a good time to treat this first generation of mites and significantly reduce damage that will otherwise occur by summer.

spruce spider mite eggs on arbovitae

Infested plants can be treated with horticultural oil that will smother overwintering eggs without harming plants. See the spruce spider mite page at 'Bugs for more information.

The second landscape pest to watch for in late winter is spruce aphid. If you've seen spruce trees with missing needles below the branch tips the damage may have been caused by spruce aphid. These tiny aphids start feeding in late winter and disappear by spring when only their damage remains to be found. These aphids can be effectively treated like other aphids with insecticidal soap but treatment must be done in late winter, not summer.

So, get out there and start gardening by looking for these winter garden pests!

Thursday, February 08, 2007

Natural botanical insecticides and pesticides

Pesticides are not all created equal

I'm usually not very enthusiastic about insecticides in general and I almost never suggest that you use them indoors. However, there are times when a carefully timed application of insecticide will bring an otherwise out-of-control pest situation back to tolerable levels.

Until recently homeowners had relatively few options when it came to safe and effective pesticides for use indoors. The only available pesticides were either a messy, smelly aerosol spray or an equally smelly powdered insecticide. Gardeners have a few more options like insecticidal soap and neem oil (see below) but even here the choices were limited.

Fortunately, times they are a changin' (apologies to Bob Dylan). There has been a real movement in the last few years toward natural pesticides, those derived from natural, not man-made, sources. And, pesticides that are safer for the user and the environment - the so called biorational pesticides. Not all natural pesticides are biorational and not all biorational pesticides are natural. The classic example is nicotine, the active ingredient in the tobacco plant. Nicotine is a natural pesticide because it is derived from a living plant but it certainly is not biorational because it is so broadly toxic to both plants and animals.

There's now a new category of natural pesticides called botanicals that meets both criteria of low toxicity and low environmental impact while being effective and easy to use. Technically speaking botanical pesticides are not new. Pyrethrum is one of the oldest natural plant products used as an insecticide and neem oil, from the neem tree, has been used for its insecticidal and medicinal properties for hundreds of years. What's new is the combination of plant essential oils in different formulations (aerosol, dust, wettable powder, liquid concentrate) that can be used in a wide variety of pest control situations.

Why do plants make essential oil pesticides?

Plants make essential oils, like clove oil and peppermint oil, as defense against their animal and disease-causing enemies. The oils are made in special gland cells where they can be released in response to feeding by an herbivore or attack by a pathogen. It makes sense that these same compounds could be used as insecticides and fungicides when extracted from the plants. In small doses some of these same essential oils are used for fragrance or flavor.

Are they safer than synthetic pesticides?

No pesticide is 100% safe and non-toxic. However, the margin of safety for botanical pesticides is generally much higher than older synthetic pesticides. Most "pesticide" products in the US require testing and registration by the Environmental Protection Agency (EPA) to ensure they are both effective and safe, when used as directed on the product label. Some of the new botanical pesticides are so low in mammalian toxicity that they are exempt from EPA registration.

Bottom line: if you use an insecticide indoors consider using one of the new botanicals instead of the older synthetic pesticides. They are both effective, much safer, and even smell better! The only downside is that they are somewhat more expensive but this should encourage you to use less! Use the link below for more information.

Tuesday, February 06, 2007

Scabies and mange mites

drawing of a scabies miteWhat causes scabies and mange?

Both conditions are caused by a tiny mite (drawing left) that burrows into the skin causing irritation and intense itching.

Many mites (tiny, eight-legged animals more closely related to spiders than to insects) cause skin irritations and allergic reactions. These include house dust mites, grocers itch mites, chiggers or red mites, and several different fowl mites.

Only one mite, however, actually burrows into the skin. These are scabies, or the human itch, mites. In cats and dogs we use the term mange to describe two different mite infestations. One of the mange mites is the same one that causes scabies in humans.

What does scabies look like?

Scabies mites are very small (female: 1/60"). They burrow into and feed under the skin. They spend their entire life cycle on the host, but can survive off-host for up to 10 days, if conditions are moist. For this reason the mites can be transmitted by infested clothing, towels, bedding, and so forth. Burrowing and feeding causes intense itching that when scratched, may lead to infection and open wounds. Hard, pinhead-size pimples containing a yellow fluid may form over infested areas. You may also see faint grayish or reddish lines under the skin.

Where does a scabies infestation come from?

Transmission of scabies mites usually is by close contact with infested individuals. Suspected infestations should be directed to a physician. This is a medical problem for the most part and cannot be handled by pest control in the home. Very effective topical lotions are available to treat scabies outbreaks. Treatment may be repeated at 3-10 days to kill mites hatching from eggs, but follow medical advice in all cases. Clothing and bedding from an infested individual should be carefully laundered or dry cleaned.

Use the links below for more biology and control information.

Sunday, February 04, 2007

Head lice and pubic lice nits

head lice and a nit attached to hair shaftWhat are lice nits?

As every parent of a school-age child probably already knows head lice are tiny "bugs" that infest the scalp and cause a lot of itching and irritation. They can affect all kids, everywhere, and can be very contagious. They are, however, really (really!) less of a medical concern than many people believe, but that argument is for another blog article. This post is about the eggs, or nits, that lice lay and what exactly the nits look like.

Nit is another name for egg. Both head lice and pubic lice (a related species that infests areas of the body where course hair grows like the groin and chest) attach their nits to the hair of their hosts (see drawing above and photo below). The nits are actually glued to the hair shaft close to scalp because they need the warmth and moisture that comes off the scalp in order to develop properly. Nits are attached so tightly that normal washing, combing, or brushing won't remove them.

Nits hatch quickly (7-9 days) under normal conditions so any nit that is more then about an inch away from the scalp is probably already hatched or is dead. As the hairs grow the attached nits (alive or dead) move away from the scalp with the lengthening hair. There's some debate about how far away a live nit can be found from the scalp. Some people say 1/4" while others say "more than an inch". The difference probably depends on local climate and perhaps differences in lice populations. Regardless, just realize that it is difficult to tell the difference between live nits and dead or hatched nits.

photo of lice egg on hair shaftEffective lice control must include "nit-picking" and combing to crush or remove these eggs (see photo left). If lice eggs are not removed they will hatch in a few days and start the infestation all over again. Combing with the proper lice comb is the best way to remove nits and there are now effective combing aids that make this job easier. Use the links below for more information about lice and lice control.

Saturday, February 03, 2007

House dust mites

What is house dust?

Obviously the answer depends on where you live and the season of the year. In general, however, house dust is composed of ash, cloth fibers, hair, plant pollen, human and animal skin, soil particles, and fungal spores. In many households, human skin flakes make up much of this flying debris. On average, an adult sheds about 1/2oz of skin every day!

What are house dust mites?

House dust mites are tiny, nearly microscopic mites that feed on the organic parts of house dust.
The mites live in fabric and bedding and for many people go completely unnoticed. For some people however dust mites can cause moderate to severe allergy.

The allergy is caused by bits of the mites themselves that become airborne, and mite feces. What goes into dust mites as a flake of skin and hair comes out the other end as an allergen that can stuff up your nose, launch a severe allergic reaction or even trigger asthma. House dust mites are not the only source of allergen in our indoor environment but they may be one of the most important.

Dust mites take about 1 month to develop from egg to adult under ideal conditions. Growth occurs between 50 and 90 degrees F. and they require fairly high relative humidity (60-90%). This need for moisture is why dust mites tend to be more numerous in the spring and fall when indoor humidity is a little higher. Winter heating dries out houses and therefore reduces dust mite numbers. House dust mites do not bite or otherwise cause harm.

Control exposure to allergen and treat the allergy

If you are not bothered by dust mite allergy then there's no need to do anything. However, if allergies are a problem there are two things you can do that might help. First, try to limit your exposure to allergen by removing as much fabric from your living space, especially the bedroom. Use mattress and pillow covers to place a barrier between you and allergen contained in bedding. Second, medically treat the allergy (see your allergist or other health care provider).

Do not try to control house dust mites with insecticides! This will only make matters worse because allergies can make your body more sensitive to the irritation of insecticide exposure.

Use the link below for more information about house dust mites and ways to deal with the allergies they can cause.

Wednesday, January 31, 2007

How do spider mites damage plants?

Spider mites can cause extensive leaf damage

spider miteSpider mites are tiny (1/32") plant-feeding mites (see drawing left) that are important pests in both home gardens and commercial agriculture. Even a minor spider mite infestation can do significant damage to plant productivity. Injury is the result of damage to the plant's protective outer layers, the epidermis and cuticle, that occurs as the mites feed. Research has shown that injury to these layers causes excessive and uncontrolled water loss and eventually injured plants dry out and die (see photo of injured leaf below).


Take a look at the photo of the two leaves. The photo was taken during an experiment to determine the effects of spider mite feeding on peppermint leaves. The leaf on the right was infested with spider mites, the leaf on the left was kept spider mite-free with a barrier of sticky material (not visible in this photo). After about 15 days the mites were removed and a variety of measurements were made to determine the health of "injured" vs. "uninjured" leaves.

spider mite damage experimentThe leaf that was fed on was dry and brittle compared to the uninjured leaf. When water loss was measured injured leaves (even dry ones) had far higher rates of water loss and this loss was uncontrollable. Healthy leaves are able to conserve water, especially at night. There were many other physiological differences that all related the leaf's ability to control water. Spider mite feeding disrupted the ability to control water loss by disrupting the leaf's protective layers.

Use the link below for additional information about the original experiments and references to the scientific literature.

Pantry or stored product pests

grain beetlesInsects that infest our stored foods

Now that the cold weather has arrived we can turn our attention indoors and think about getting rid of those pesky "weevils" and moths that are occasionally found in the kitchen and pantry.

Did you know that insects consume 10-50% of all stored grain worldwide? Most of the loss occurs in commercial storage but a significant amount also happens after consumers take food home and store it improperly. So perhaps we needn't worry so much about producing more food on the farm but should concern ourselves instead with protecting the food we already have in storage!

Here's some basic information about the most common pantry or stored product pests and what you can do about them at home.

Keep in mind the following points: (1) Dry pet food is the most commonly overlooked source of infestations. (2) Do not store items longer than about 2 months unless steps are taken to protect it against infestation (see below). (3) Do not store items in the thin plastic "supermarket" bags because insects can chew through this plastic; use heavy plastic, glass or metal containers instead. (4) Freeze products like birdseed, dry pet food, and flour, before placing them in long-term storage -- freezing can effectively eliminate many insect pests (see below). (5) Discard infested foods when it is found. Trying to salvage food that has become infested with insects is usually not practical and may only provide an ongoing source of infestation.

Weevils - The term "weevil" is often used to describe a wide variety of beetles and true weevils that infest seeds, whole grains, and flour. Some stored-product beetles require whole, unbroken kernels (see photo above) whereas others infest grain meal and flour.

Meal moths - Adult moths are about 5/8" across the wings. Their wings often have a broad, dark band across the back (Indian meal moths). Larvae, "worms", infest a wide variety of foodstuff including grains, dried fruits, seeds, crackers, nuts, powdered milk, dry pet food, and cereals. Webbing produced by larvae is commonly found covering infestations. You may also find moths in the kitchen or other rooms. Meal moth infestations are common in shelled or unshelled nuts, especially walnuts. Spilled pet food is another likely source of infestation.

Flour beetles - A pest of flour, this beetle cannot attack unbroken kernels. Also found in peas, beans, shelled nuts, dried fruits, spices, etc. One generation is completed in 2 to 3 months. You must find all infested foodstuff and dispose of it in order to control this insect.

Dermestid or carpet beetles - There are a number of small beetles that feed on animal hair, hide, and stored food. Dermestid or carpet beetles are notorious scavengers feeding on all manner of dead animal protein. Some of these beetles infest stored food as well. Their presence is often detected when the cast skins of their "fuzzy" larvae are found in kitchen draws or on shelves (see carpet beetle link below for photos).

A word of caution about using insecticides around food

Controlling stored product pests with insecticides is very difficult and usually
not recommended because of the proximity of food to the applied poisons. Most of the time stored product pests can be adequately managed with proper sanitation, traps and attention to how packages are sealed and stored. Most importantly, don't store foods longer than about 2 months unless you freeze them first.

If, however, insecticides are used indoors use only the new botanical insecticides, specifically those that are exempt from EPA registration (see the link above for products that are available to homeowners). These insecticides are very effective when used according to their label instructions, much safer for you and the environment, but are somewhat more expensive than conventional pesticides.

How to protect foods with cold treatment

Freezing kills all stages of stored-product pests like moths, beetles and weevils. After cold treatment foods can be removed from the freezer and stored at room temperature in a sealed container. Even packaged foods like flour, dry pet food, dried fruit and so forth can harbor live insects. If these products are placed in storage at room temperature insects will start to multiply resulting in an infestation. On average it takes about 2 months for these infestations to develop. This is why we suggest that you treat food products with cold if you plan to store them longer than about 2 months.

The rules for cold treatment are to keep the package small enough and the time-in-freezer long enough to ensure that the product completely freezes. For example, a five pound bag of flour might take 3-4 days at normal freezer temperature whereas a 1 pound box of raisins might take only 2 days. Freezer times will largely be a guess at first as there are no hard and fast rules. Just remember to keep the package small and time in freezer as long as possible.

Use the links below for specific information about identification, trapping, and control of these stored product pests.

Monday, January 29, 2007

Get rid of fleas now!

Fleas can be a problem for every dog and cat owner. Adult fleas feed on the blood of warm-blooded animals. While they also bite people, we are not their preferred host. Flea bites cause swelling and itching on both us and our pets. Immature, or larval, fleas look like small white worms. They don't bite but instead feed on hair, shed skin, and dried blood in the animal's bedding. See this page for photos of adult and larval fleas.

Below is an inexpensive flea control program that works very well; it can be time consuming but all the steps are important. If you skip any of the steps fleas may be a recurring problem. For methods that are easier but more expensive see flea control at 'Bugs.

Inexpensive flea control

(1) Vacuum rugs, drapes and furniture thoroughly . Pay particular attention to areas where pets sleep. Discard the dust bag outside because it contains fleas, flea larvae and eggs that may re-infest the house. Vacuuming is an important first step!

(2) Treat rugs, drapes and furniture, and any outdoor sleeping areas like a dog house, with methoprene (IGR; see below). Use these products according to label instructions. Some methoprene products also contain other insecticides like pyrethrum.

Insect growth regulators (IGR) act by disrupting normal flea development -- non-biting larvae never develop into adults and eventually die. IGRs are virtually non-toxic to humans and pets and are long-lasting, up to 7 months by some reports. The downside of IGRs is that they are slow acting.

(3) Shampoo your pet with a good quality flea shampoo at the same time as steps 1 and 2. Repeat the shampoo in a few weeks when you notice adult fleas again.

Use of flea collars

Flea collars do pretty well at keeping ticks off the front half of dogs; however, they don't have much value against fleas -- especially if the home is infested.

Outdoor treatments

According to the best information we have, outdoor insecticide treatments are not needed and of little value. This is because fleas live in the animal's nest or bedding. They don't survive for long away from their animal host. So, you can skip the general lawn treatments for fleas.

Use of foggers or "bombs" (total release aerosols)

Aerosol foggers or "bombs" are popular with some homeowners. The idea is that the aerosol insecticide somehow penetrates into cracks and crevices that you couldn't reach by other means. In fact, total release aerosols do a poor job of coverage because they essentially throw insecticide into the air thereby treating only exposed surfaces as it lands. On the other hand, liquid formulations, carefully applied with some type of pressure applicator, will achieve much better coverage and might even be less expensive.

See the flea control articles below for more detailed information.

Sunday, January 28, 2007

Black fly "mystery" at Scotty's Castle solved! :)

The mysterious appearance of black flies, which are normally found around white water rivers and mountain streams, at Scotty's Castle in Death Valley National Park, one of the driest places on earth . How do these aquatic insects survive in this desert??? The mystery is explained at the Black Fly @ Scotty's Castle page.

Saturday, January 27, 2007

Borate (boric acid) compounds for insect control

We frequently get questions about the various borate products on the market to control insects around the home. These products are used to control ants, cockroaches and structural pests like carpenter ants, powderpost beetles and dry-rot fungi.

General characteristics

Borates offer a low toxicity alternative to conventional insecticides, but
are slow acting and may take several weeks to be completely effective. Borates are also generally long lasting, if kept dry. And, borates are generally not used outdoors because of they are soluble in water. Borate is primarily an insect stomach poison and fungicide. Stomach poisons must be eaten by the pest to be effective.

Borate Products

Timbor and Bora Care (and a few others) are products for structural pest control (termites, carpenter ants and wood-boring beetles). Timbor is a powder of 98% disodium octaborate tetrahydrate, a sodium salt of boric acid, and Bora Care is a 40% solution of the same compound plus ethylene glycol.

Timbor can be used to treat wall voids for carpenter ants and/or cockroaches, silverfish, etc. Timbor powder may also be dissolved in water and applied as a solution. Bora Care, on the other hand, is always applied as a spray to protect wood against chewing insect attack (carpenter ants, termites, wood boring beetles, etc.) and dry-rot fungi. Bora Care contains ethylene glycol which may help in penetration of wood fibers.

Borate powder ("Roach Pruf", "Roach Powder") is an excellent alternative to conventional insecticides for cockroach control as well. The powders can also be formulated as a homemade ant bait. My own experience is that borate powders, when used correctly, are very effective but slow acting. When used to dust wall voids, it will eliminate carpenter ant colonies and prevent re-infestation. Sometimes borate treatments are combined with a faster knockdown insecticide like pyrethrum.

Thursday, January 25, 2007

Clothes moths added to 'Bugs

I've just posted a new page about clothes moths at our 'Bugs site. Clothes moth larvae ("worms") can do significant damage to many kinds of natural fabrics. This new page explains identification, trapping and control of clothes moth.

Saturday, January 20, 2007

Happy New Year! to the friends of 'Bugs

2006 was a good year for 'Bugs overall. At the start of the year, however, 'Bugs was still in the clutches of the dreaded Google "sandbox" and, as such, our visitor count was fairly low. We got out of the sandbox, briefly, in March but it was not until the end of June when we finally emerged for good (I hope!).

During the year we added 48 new pages with topics from ant bait to insect stings.

New pages already in '07

Pest Control Suppliers Online
Flea Traps
Ant Control
Synthetic vs. Organic Pesticides

We are looking forward to seeing all of you in '07! Let us know if we've missed an important Bug topic.