Text Size:   A+ A- A   •   Text Only
Find     
Site Image
Frequently Asked Questions
I found an unusual insect in my house/yard. Can ODA identify it?
In most cases it is very difficult to identify an insect over the phone. If you need it identified place it in a container with a tight fitting lid. Call ODA (1-800-525-0137) to obtain details on preserving and sending the insect(s) for identification. After you call and receive mailing instructions, you may send samples to the Oregon Department of Agriculture, Plant Division, IPPM, 635 Capitol St. NE, Salem OR 97301. An ODA entomologist will examine it and contact you. Or, you may take the specimen to your local OSU extension office.
What are the webs that I see in my trees? Gypsy moth?
These large webs are created by the fall webworm, a native insect that is widespread in western Oregon. The adults are moths about three quarters of an inch long and mostly white. They come out of their cocoons in June, mate, and then lay eggs on a wide variety of trees, including alder, apple, ash, cherry, cottonwood, poplar, walnut, and madrone.

The caterpillars hatch in July and start making very small webs together. The silk webs become noticeable in August. Sometimes there are several webs per tree, and sometimes the tree is entirely covered in webs.


fall webworm

Fall webworm web on Sauvie Island, Oregon.

By late summer or early fall the caterpillars are full-grown. The caterpillars start to wander from the nests in search of places to make cocoons and overwinter. The adults emerge the following year to start the cycle again.

By comparison, gypsy moth adults come out in late summer, mate, and then females lay egg masses that overwinter. The caterpillars hatch in the spring when the buds break. Immediately they climb up into trees and begin feeding or they make silk “balloons” and drift in the wind to trees farther away. The caterpillars feed continuously through June but do not make webs. The adults hatch from the cocoons in August or September and start the cycle again. The best host trees for gypsy moth are oaks but, like fall webworm, can feed on a very wide variety of broadleaf trees.

Three key differences between gypsy moth and fall webworm are (1) gypsy moth caterpillars don’t make webs and (2) the two species are found during different times of the year, and (3) gypsy moths are not native to Oregon. They have been introduced repeatedly but all populations have been eradicated. 
How do I know if I have a brown recluse/hobo spider in my house?
First, it is unlikely that you will find a brown recluse spider in your home since they are not known to occur in Oregon. Brown recluse spiders live in the south central Midwest from Nebraska to Ohio and south through Texas to Georgia. However, you may find a hobo spider, giant house spider, or European house spider in your home. These three spiders are related and they look very similar. If you examine them closely slight differences in appearance may be observed, but these differences are not a reliable way to positively identify them. Giant house spiders are often, but not always, larger and a little darker in color than hobo spiders. European house spiders usually have an irregular pattern on the abdomen and their legs are usually banded with grey rings. The hobo spider usually has a distinct herringbone stripe on its abdomen. The best way to distinguish a hobo spider from the giant house spider and European house spider is to have specialist such as an entomologist at ODA examine it. Although hobo spiders are common in the Pacific Northwest, bites are rare. When bites occur it is usually because a spider was trapped against the skin. For more information please visit our ODA web page about the hobo spider .
My screens are covered with boxelder bugs. What can I do?
Boxelder bugs over-winter as adults in protected areas such as garages and cracks and crevices in homes. They can be a nuisance from fall through early spring. The most effective method of keeping them away from your house is to remove their favorite food source from your yard: maple and boxelder trees. A less permanent solution, if you don’t remove the host trees, is to add screen to any building crevices or openings, call a pest control company to treat the outside of your house with insecticides, or use a vacuum inside the house. Although they can be a nuisance, they won’t damage your house (they are not structural pests), don’t bite or sting, or get into your food.
What are these tiny bugs crawling all over me that I can't see?
First, there are not many arthropods that live on or feed on humans. Many insects you see on yourself are probably there by accident, especially if you had been outdoors brushing up against plants. Once you brush the insects away you won’t be bothered anymore. If you continue to be bothered by insects crawling on you, the pest will need to be identified before what would help can be determined. If an arthropod is not identified as the source of the problem, it may be caused by several medical conditions. In general, ODA identifies insects associated with plants and not humans. For more information see the links below. For more help contact your physician or the dermatology department at OHSU (503) 418-3376.
 
Related links:
OHSU dermatology
UC Davis pest notes
Texas AgriLife Urban Solutions Center "Insects in the City"
UF Human Pest Insects  

What are all of the little insects in my kitchen?
If you start seeing many small beetles or small moths flying around in your kitchen you may have a stored products pest. These are pests that feed on foods that are stored in containers or boxes such as whole grains, flour, pasta, cereal, dried fruit, chocolate, or even wild bird seed or pet food. The best way to eliminate the insects is to find the source of the infestation in your stored foods. Check the containers for webbing, powder, or small insects or larvae. Anything that is contaminated should be disposed of or re-infestation is likely to occur. If possible place the contaminated food in the freezer for several days before disposing of the food. To prevent a future infestation, keep all foods in tightly sealed containers, not cardboard, paper, or plastic bags. Keeping pantries, kitchen cabinets and other food storage areas free of debris that could harbor stored product pests is also important in preventing and controlling infestations.
 
Related links:
OSU's web site on meal moths

I have a swarm of aggressive bees. Are they Africanized?
First, are you sure that you have a swarm of honeybees or are they wasps? Wasps and hornets have narrow waists, are smooth (not hairy), and feed on insects and other arthropods. Honeybees are more robust, very hairy, and feed on nectar and pollen from flowers. Wasps may have a long, noticeable narrow waist, and are likely patterned with contrasting bright yellow and black. Honeybees may be about the same size as yellow jackets but are banded with brown or amber contrasting with black.

Honeybees that are swarming are generally not aggressive. They have just gorged on honey and they don’t have a home to defend. You still shouldn’t get too close to the swarm (stay at least 20 to 30 feet away).

In Oregon, it is unlikely that the bees are Africanized bees. They are known to occur in southern California and parts of Nevada, Arizona, New Mexico, Texas, and Oklahoma. Africanized bees can only be distinguished from European honeybees by laboratory analysis.

Call a pest control company (look under "bee removal" in the phone book) if you need to have the swarm removed. Sometimes local beekeepers can help. Or, you can wait until they leave on their own. A swarm may last just a day or it may last as long as several days.

What are these insects all over the outside of my house?
There are quite a few different types of insects that you may notice on the outside of your house. Some insects may land on your house to warm up in the sun or they happen to land there because they are in high numbers in your yard, or others may seek refuge in cracks and crevices for the winter. The most noticeable insects that aggregate on houses in Oregon are the multicolored Asian ladybird beetle , cluster fly, grass bug, boxelder bug, and brown marmorated stink bug.
 
Related links:
OSU's cluster fly web page
OSU Extension's flyer on boxelder bug
University of Florida's Featured Creatures: Asian ladybird beetle
Michigan State University: multi-colored Asian lady beetle
 

I've been bitten by an insect. Can ODA identify it?
If you are stung or bitten by an insect or other arthropod ODA can identify it if you catch it and preserve it properly. Please call ODA (1-800-525-0137) to obtain details on preserving and sending the insect(s). After you call and receive mailing instructions you may send samples to the Oregon Department of Agriculture, Plant Division, IPPM, 635 Capitol St. NE, Salem OR 97301. An ODA entomologist will examine it and contact you.
I think I have been stung by a fire ant. What should I do?
Since it may be too difficult to catch any ants for identification without getting stung, please call ODA (1-800-525-0137) to speak with an entomologist. Imported fire ants are not known to be established anywhere in Oregon. We appreciate any help you can give us in finding imported fire ants in Oregon so we can eliminate them before they become established and spread. For more information you may visit our page on imported fire ants.
How do I protect myself from West Nile Virus? Who can I call?
The CDC web site has information about protecting yourself from West Nile virus. In addition, the page contains the numbers of reported cases and helpful links. You may also call 503-988-NILE for more information.