For nearly every plant in the home landscape, there is an aphid species that feeds on it. Fruit trees are no exception. Apples host a green apple aphid, cherries host a black cherry aphid (Myzus cerasi), and peaches and nectarines host a green peach aphid (M. persicae). While aphids rarely damage the fruit itself, they can compromise the health of a fruit tree, reduce the size of the fruit, and deposit a sticky substance called honeydew on the surface of fruit and leaves.
There are many beneficial insects that graze on aphids, and in most years, these natural enemies do a fair job of keeping aphid populations in check. Beneficial insects include lady beetles, lacewings, syrphid flies, and parasitic wasps that sting and lay eggs in aphids. Learn to recognize these beneficial insects and conserve them. Many types of beneficial insects can be drawn to the home landscape by planting certain flowers in the yard, such as asters and legumes, as ground cover beneath the fruit tree. Perhaps one of the best ways to conserve these biological agents is to minimize pesticide use. Organic pesticides products should only be used when necessary to protect the fruit and maintain the health of your tree.
For more information on organic management of tree fruit pests see the WSU Extension manual EM066E- Organic Pest and Disease Management in Home Fruit Trees and Berry Bushes by Drs. Charles Brun and Michael Bush on-line.
For more information on beneficial arthropods in the home landscape, see the WSU Extension manual EM067E- Beneficial Insects, Spiders, and Other Mini-Creatures in Your Garden: Who They Are and How to Get Them to Stay by Dr. David James on-line.
Submitted by: Michael R. Bush, June 8, 2015
As a newcomer to our home landscapes in the Pacific Northwest (PNW), the European paper wasp, Polistes dominula, has a reputation as both a beneficial predator and a pest. The European paper wasp is a relatively tame wasp that forages within landscape plants in search of leaf-feeding caterpillars and other insect prey. However, it is also a nuisance pest that will sting people who accidentally disturb or threaten it or its nest.
In early spring, homeowners may remove wasp nests by knocking them down with a long broom, pole, or strong stream of water from a hose. This is the best time to remove a nest because only a single female will be guarding it. It may take repeated removal of each nest to discourage the wasps from replacing it. It is important to wear gloves and protective clothing to reduce any risk of getting stung, and although the sting is mild, it will get your attention.
For more information, go to The European Paper Wasp FS152E located at http://cru.cahe.wsu.edu/CEPublications/FS152E/FS152E.pdf.
Submitted by: Mike Bush and Todd Murray, March 31, 2015
Before planting a backyard cherry tree, homeowners should consider the challenge of pest management, especially management of the western cherry fruit fly (WCFF).
Fruit infested with the cherry fruit fly larvae, known as maggots, may have a dimpled appearance, but the maggots can still be difficult to detect when examining the surface of the fruit. However, as the maggots mature, they break the surface of the cherry and open a hole in order to breathe and exit the fruit.
There are relatively few proven strategies that homeowners can use to manage this pest. The primary non-chemical strategy to manage WCFF is to pick off every cherry from the tree at harvest. WCFF management will be considerably easier for homeowners who plant fruit trees grafted to dwarfing rootstocks. For a list of pesticides (including organic products), homeowners can access the WSU Hortsense website at http://pep.wsu.edu/hortsense/ .
For more information on organic management of tree fruit pests see the WSU Extension manual FS125E- The Western Cherry Fruit Fly and Your Backyard Cherry Tree by Michael Bush and Marianne Ophardt on-line at http://cru.cahe.wsu.edu/CEPublications/FS125E/FS125E.pdf
Submitted by: Mike Bush, February 9, 2015
Drosophila suzukii, commonly known as Spotted Wing Drosophila or SWD, is of concern to home gardeners and commercial producers. It was first detected in the continental US in California in 2008 and quickly spread up the coast into Canada and across the country. There are over 2,000 native drosophila flies in the US but SWD is unique in that it lays eggs inside ripening fruit as well as rotting fruit. The maggots hatch from these eggs and feed inside fruit, rendering it inedible.
It is considered a serious threat to fruit and berry crops including cherry, raspberry, blackberry, blueberry, strawberry and some peach varieties. There may be several generations of SWD produced during the growing season, which makes this pest particularly difficult to manage, especially on crops ripening after July. Preventing the spread of SWD in home gardens can ensure the production of homegrown fruits and berries and reduce the threat it poses to commercial producers of fruits and berries.
For information on detecting and managing this pest, see:
Spotted Wing Drosophila (SWD) Monitoring, Identifying, and Fruit Sampling. FS049E and WSU Hortsense,
Submitted by: Dave Pehling, June 26, 2014
If you grow apples, the codling moth will come! The larva of this common pest, also known as “the worm in the apple,” directly impacts the eating quality of apples across the state of Washington. When left unmanaged in backyard trees, the codling moth can damage as much as 80 to 95 percent of the fruit—making it “wormy” and unfit to eat.
Figure 2) Apple fruit with signs of codling moth infestation; look for the conspicuous piles of brown granular excrement plugging the entrance hole on the surface of the apple. Photo Credits: Michael Bush, WSU Extension
Washington homeowners must protect their apple or pear fruit from two, or sometimes three (in the warmer regions of the state) generations of codling moth each year. The adult moths fly during warm evenings, with peak activity in May, July, and late August. The best means of protecting backyard fruit trees from codling moth infestation is an integrated pest management (IPM) program utilizing several control strategies.
1) Plant your fruit trees on dwarfing or semi-dwarfing rootstocks.
2) Scout your fruit (weekly) from late May to apple harvest time for signs of codling moth larvae infestation. Pick off infested fruit and crush to kill larvae protected inside the fruit.
3) When the fruit is less than 1 inch in diameter (early to mid-May), individually bag each fruit left on the tree. Standard paper bags or commercially available apple bags can be used.
4) If pesticides are used, they must be applied during adult moth activity so that the pesticide covers the fruit surface before the eggs hatch. Pesticide sprays should start 17 to 21 days after full bloom (about 10 days after most of the flower petals drop from the tree) to target the newly hatched larvae before they bore into the fruit. For a list of effective pesticides used to manage codling moth, homeowners can contact their local WSU Extension office or visit the WSU Hortsense website.
For more information, see Codling Moth and Your Backyard Fruit Tree.
Submitted by: Michael Bush & Marianne Ophardt, May 23, 2014
Did you know that, as a complement to the Washington State University Gardening Blog, the WSU Extension Gardening Team has also developed pest sightings LISTSERV? The LISTSERV will alert you to new pest information and other major pest news.
While we will stick to home and garden insects, diseases, weeds and vermin, the list may also interest Agriculture/Horticulture/Natural Resource researchers, educators and Master Gardeners.
To join, visit the following link:
http://lyris.cahe.wsu.edu/read/all_forums/subscribe?name=pestsightings-hg&page=all_forums or email: firstname.lastname@example.org with the word “subscribe” in the subject line.
Why would you want to join yet another WSU LISTSERV? Here’s a sample of recent notices:
- Japanese beetle news
- Watch for mountain ash sawfly
- Anthidium manicatum found in Granite Falls
- Be on the lookout for brown marmorated stink bugs
- Springtails are aggregating, etc.
Short and to the point, news you can use.
Feel free to contact Todd Murray (email@example.com) with any questions.
Submitted by: Todd Murray, April 25, 2014
Whether it is spring fever or the opening of the Master Gardener Clinic in Yakima County, March and April tends to bring out the worst in bed bug sightings. Since bed bugs are household pests, there should be little or no seasonality to bed bug abundance.
The saying “sleep tight, don’t let the bed bugs bite” is not just a quaint bedtime rhyme, but also a reminder that bed bugs do exist, and they require human blood meals to survive and provide for their offspring. In today’s highly mobile society, bed bugs have reestablished themselves as household pests. Bed bugs are not known to transmit human diseases, but they can cause skin welts, local inflammation, and contribute to insomnia.
Bed bugs have been found in homes, apartments, rental units, and even hotels throughout Washington with increasing frequency. Cimex lectularius is the most common species that feed on humans.
1) Avoid introducing bed bugs into your home. Homeowners should not acquire second-hand mattresses and upholstered furniture without first quarantining them.
2) Remove or replace any infested furniture, including mattresses, box springs, couches, and upholstered chairs, whenever possible.
3) Clean and vacuum furniture and mattresses and wash bedding weekly. This will reduce, although not eliminate, bed bug infestations.
4) Establish a barrier or space between the bed and the floor to further discourage bed bugs from climbing onto the bed (remember bed bugs are wingless and cannot fly).
5) Obtain pesticides labeled for indoor use against bed bugs. Look for an annually revised listing of these products on the WSU Pestsense website at http://pep.wsu.edu/pestsense/.
6) Inspect sleeping areas in rooms adjacent to the infested area since these surprisingly mobile, yet wingless, bugs can move into surrounding areas.
The incidence of bed bugs is on the rise in North America, so precautions to avoid introducing them into your home are prudent. Bring any bugs found during a home inspection or captured on sticky traps or cards to your local Extension office for identification. While there are management strategies that homeowners can take to reduce the incidence of bed bugs in an infested household, the best management strategy is to cooperate with a local pest control professional to eradicate the problem.
For more information on Bed Bugs: Recognition and Management go to http://cru.cahe.wsu.edu/CEPublications/FS070E/FS070E.pdf
Submitted by: Michael Bush, April 8, 2014
The lily leaf beetle (LLB), Lilioceris lilii, is a bright red beetle in the chrysomelid family native to Europe and Eurasia. In its native range, LLB is a pest of exotic and hybrid lilies. Researchers in the eastern United States have found Asiatic lily hybrids to be most susceptible to LLB while some Oriental varieties are resistant. Lilium henryi ‘Madame Butterfly’, L. speciosum ‘Uchida’, L. ‘Black beauty’, L. regale and L. ‘Golden Joy’ appear to be most resistant.
Adult beetles overwinter in the soil and emerge in the spring to feed on developing foliage and seek mates. Adult beetles are very active and mobile, and they make a defensive chirping or squeaking noise when provoked. Mated adult females lay eggs in small batches in irregular rows…laying up to 450 eggs during the season. Newly emerged larvae feed on the undersides of leaves. As larvae mature, feeding damage becomes more apparent on older leaves and sometimes stems and flowers.
See Todd Murray’s “Pest Watch: Lily Leaf Beetle.” http://cru.cahe.wsu.edu/CEPublications/FS084E/FS084E.pdf