Common Pests

Several aphids on a plant

Control pests without pesticides! 

The links below will take you to an NCAP webpage or factsheet (PDF) with additional information about that pest. NCAP grants permission to print out and copy these articles. You may distribute as many printed/photocopied copies as you want, but they must be free to recipients. Also see our Pest Management Guide for a step-by-step process for dealing with pests.

For expert advice tailored to your pest or weed issues, check out our sliding scale Pest and Weed Management Consultation services.


Despite the beneficial role ants play outdoors, ants become pests when they enter homes in search of food, water, and shelter. If ants do invade your house, don't panic. A management plan based on sanitation and physical controls can effectively reduce household ant populations while still allowing ants to play their part in the environment.

AZALEA LACE BUG (factsheet)

Azalea lace bug is the most damaging species in its genus that is associated with landscape plants. This pest is a major concern in the nursery industry because of the aesthetic damage it causes to plant foliage.


Have you found drops of honeydew on your car after you've parked it under a tree? Or have you found more than broccoli when you're cutting up a freshly-picked head from your garden? You're probably dealing with aphids, a common insect in yards and gardens. Don't reach for an insecticide, though; there are straightforward ways of dealing with these small creatures without having to use pesticides.


Resources especially useful for property managers and others dealing with a large outbreak of bed bugs, without resorting to the use of harmful chemicals.


If you'd like to do something other than reach for a spray can of poison to deal with stinging bees and wasps, you'll first need to correctly identify the insect and determine whether it's a threat.

BILLBUGS (factsheet)

You can prevent billbug problems by planting varieties of grass that discourage billbugs and watering your lawn as needed to keep it healthy. If billbugs are damaging your lawn, beneficial nematodes are an effective, pesticide-free solution. 

BOX ELDERBUGS (factsheet)

Living with box elderbugs may be the easiest and simplest solution you'll find. If you've got more of these bugs than you can comfortably live with, try pesticide-free techniques, such as standard cleaning.


If you've found furrows, holes or threadbare spots in your woolens you've got clothes moths.


A "worm" in homegrown fruit is not really a worm, but most likely a codling moth caterpillar. One of the most damaging insects of apples and pears, it can be a problem in commercial orchards as well as for backyard fruit trees.


If you check on your garden and notice your tender young seedlings look like someone has taken a mini-lawnmower to them, you may be dealing with cutworms. There are hundreds of species of cutworms, but basic control methods in the garden are the same for all types.

CRANE FLIES (factsheet)

In order to keep crane flies at bay, keep your lawn healthy by giving it adequate fertilizer and water. If your lawn has shady areas think about planting a shade-loving grass or another ground cover. Dethatch your lawn as necessary, because thatch is a perfect place for leatherjackets to grow. Crane flies are rarely serious lawn pests. Most of the time they are not abundant enough to cause permanent damage to healthy grass. If crane fly numbers in your lawn are too high (over 25 leatherjackets per square foot) treatments with beneficial nematodes can reduce their numbers.


It is easy to forget, especially in urban environments, that deer are wild animals with excellent survival instincts that all prey animals possess. This makes them very wary and difficult to control. And sometimes there is the other problem. Deer can become so accustomed to people that they lose their survival instincts and become hard to chase away! This also makes them difficult to control. Working with deer always requires patience and tenacity. Many times it will take a combination of approaches to get the level of control that makes you happy.


No need to wig out, there are some easy ways to keep earwigs under control. Fun Fact: It's unusual for insects to nurture their young, but female earwigs take care of their eggs and young offspring. They bring food to the nymphs and fend off predators with their pinchers.


Fleas can cause animals a great deal of discomfort and stress. Wash throw rugs and bedding weekly, use flea combs, vacuum, and apply nematodes to soil where your pets spend time. Note: See FDA warning from September 2018 for certain flea and tick products that can lead to neurological damage.


The only sure way to control fruit flies is to locate and eliminate potential breeding places. Try these traps to keep fruit flies under control without pesticides.


If you've ever watched one of your prized garden plants disappear into a gopher's burrow, you know that gophers can be pests. Fortunately, there are effective pesticide-free techniques for dealing with problem gophers.


Grasshoppers can pose a significant threat to your garden or farm, especially during the nymph stage when they feed voraciously on a wide variety of plants. Large grasshopper outbreaks usually happen every 7 to 10 years in the Northwest. Learn some natural ways to deal with these pests.


Indian meal moths are the most common of the so-called "pantry pests." As adult moths they are harmless, but the larvae are the culprits when it comes to eating and contaminating stored foods in the cupboard.


Learn how to follow the basic 5 steps of the IPM process, in order to minimize the use of pesticides at all costs. 


True to their name, lacewings have two pairs of wings “laced” with intricate veins. Though they look fragile and gentle, lacewings are avid predators. Known in their larval stage as “aphid lions,” lacewings prey on many unwanted common yard and garden insects. 


Keep mice out of your home by eliminating all openings larger than ¼ of an inch wide. Store food carefully and keep shrubs and brush away from your house. And remember not to use pesticides. If you do, the rodents may die inside your walls and start to emit a strong and offensive odor. Pesticides can also harm your children and pets!


Moles are significant contributors to healthy soil. Raking away the mounds they create is the ideal solution, but if you are too burdened by them you can replace grass with other ground covers, use castor oil, or trap the moles.


Mosquitoes are animals most of us would rather do without. When they also carry a disease, such as West Nile virus, the need to protect ourselves from their bites seems even more important.


Do you live in an area with a mosquito abatement program? You may be able to opt out to avoid pesticide spraying on your property. A law passed by the Idaho legislature in 2007 allows people to submit their own mosquito control plans, in order to opt out of their local spraying program. Utilize this law in Idaho, or to see about adapting it to your local area. 


Pillbugs and sowbugs are garden residents that look somewhat like mini-armadillos. Feeding on decaying materials, they can be beneficial recyclers in gardens, but sometimes they become pests when they feed on young shoots and roots, or on fruits and vegetables that lie on damp ground.


Rats eat our food and contaminate it with urine and droppings, carry and spread diseases, and will bite if threatened. Get up to speed on rats and how to control them without using poisons.

ROOT WEEVILS (factsheet)

The purpose of this guide is to provide home gardeners, landscapers and nursery growers with information on the identification, detection, sustainable
removal, and prevention of root weevils. Root weevils cause substantial economic losses and aesthetic damage of flowering shrubs and food plants.


Try some simple steps to keep your garden free of both pesticide use and slug problems. Clear away weeds, stones, boards, and other shelter for slugs; handpick them off your plants as needed; and use slug traps and barriers when necessary. 


Many people find spiders repulsive and scary, yet the majority of spiders are harmless and beneficial. Spiders make a very significant contribution to insect control.


There are about 3,000 different spiders in North America, but only a few of them cause problems for people.


Squash bugs are one of the most troublesome pests of pumpkins, winter squash, and sometimes melons. 


Termites perform an essential ecological function: they help break down dead wood and return nutrients and other components of this wood to the soil and atmosphere. Unfortunately, when they perform this same function in a house or other wooden building they become a pest. 


Worried about ticks? Never fear! There are several pesticide-free ways to prevent ticks from affecting you. Modify your landscape, wear clothes that fit tightly around your wrists, ankles, and waist, and don’t let your pets climb onto the furniture.


There are many ways to reduce vole populations, including heavy mulch, mowing, soil cultivation, wire fences, and mouse traps. It is important to remember that voles are an essential link in the food chain, however, and cause no major damage when at reasonable population levels.


Simple, least-toxic control methods to manage tent caterpillars and web worms.


Although they are useful insects, yellow jackets can also be painful pests. You can solve your yellow jacket problems without pesticides by reducing attractive food or drink and trapping when necessary.