Washington State University

Gardening in Washington State

Archive for March 2015

A Beneficial Wasp in the Wrong Place, Wrong Time Becomes a Pest

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.

Paper wasp

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

Submitted by: Mike Bush and Todd Murray, March 31, 2015


References for rubber mulch fact sheet

Arthur, M.A. and Y.T. Wang. 1999. Soil nutrients and microbial biomass following weed-control treatments in a Christmas tree plantation. Soil Science Society of America Journal, 63(3):629-637.

Azizian, M.F., P.O. Nelson, P. Thayumanavan and K.J. Williamson. 2001. Environmental impact of crumb rubber asphalt concrete leachate contaminants from highway construction and repair materials on surface and ground waters. American Chemical Society Abstracts 221(1-2): ENVR 15.

Bush, E., A. Owings and K. Leader, K. 2003. Foliar accumulation of zinc in tree species grown in hardwood bark media amended with crumb rubber. Journal of Plant Nutrition 26(7):1413-1425.

Bush, E., K. Leader and A. Owings. 2001. Foliar accumulation of zinc in tree species grown in pine bark media amended with crumb rubber. Journal of Plant Nutrition 24(3): 503-510.

Calkins, J.B., B.T. Swanson and D.L. Newman. 1996. Weed control strategies for field grown herbaceous perennials. Journal of Environmental Horticulture 14(4):221-227.

Chalker-Scott, L. 2007. Impact of mulches on landscape plants and the environment – a review. Journal of Environmental Horticulture 25(4): 239-249.

Christiansson, M., B. Stenberg and O. Holst. 2000. Toxic additives: A problem for microbial waste rubber desulphurization. Resource and Environmental Biotechnology 3(1): 11-21.

Ginsberg, G., B. Toal and T. Kurland. 2011. Benzothiazole toxicity assessment in support of synthetic turf field human health risk assessment. Journal of Toxicology and Environmental Health Part A 74(17):1175-1183.

Gualtieri, M., M. Milani, M. Camatini, M. Andrioletti and C. Vismara. 2005. Toxicity of tire debris leachates. Environment International 31(5): 723-730.

Kanematsu, M., A. Hayashi, M.S. Denison and T.M. Young. 2009. Characterization and potential environmental risks of leachate from shredded rubber mulches. Chemosphere 76(7):952-958.

Li,X.L., W. Berger, C. Musante and M.I. Mattina. 2010. Characterization of substances released from crumb rubber material used on artificial turf fields. Chemosphere 80(3):279-285.

Llompart, M., L. Sanchez-Prado, J. Pablo Lamas, C. Garcia-Jares, E. Roca and T. Dagnac. 2013. Hazardous organic chemicals in rubber recycled tire playgrounds and pavers. Chemosphere 90(2):423-31.

Ruffino, B., S. Fiore and M.C. Zanetti. 2013. Environmental-sanitary risk analysis procedure applied to artificial turf sports fields. Environmental Science and Pollution Research 20(7):4980-4992.

San-Miguel, G., G.D. Fowler and C.J. Sollars. 2002. The leaching of inorganic species from activated carbons produced from waste tyre rubber. Water Research 36(8): 1939-1946.

Simcox, N.J., A. Bracker, G. Ginsberg, B. Toal, B.Golembiewski, T. Kurland and C. Hedman. 2011. Synthetic turf field investigation in Connecticut. Journal of Toxicology and Environmental Health Part A 74(17):1133-1149.

Smolders, E. and F. Degryse. 2002. Fate and effect of zinc from tire debris in soil. Environmental Science and Technology 36(17): 3706-3710.

Snoddy, E.T. and A.G. Appel. 2013. Mulch preferences of the Asian cockroach (Dictyoptera: Blattellidae). Journal of Economic Entomology 106(1):322-328.

Solano, L., A.G. Ristvey, J.D. Lea-Cox and S.M. Cohan. 2012. Sequestering zinc from recycled crumb rubber in extensive green roof media. Ecological Engineering 47:284-290.

Steward, L.G., T.D Sydnor and B. Bishop. 2003. The ease of ignition of 13 landscape mulches. Journal of Arboriculture 29(6): 317-321.

Stokes, V. 2012. Some biodegradable mulch materials provide effective weed control during establishment of ash (Fraxinus excelsior L.) on farm woodland sites. Quarterly Journal of Forestry 106(4): 257-268.

U.S. Environmental Protection Agency (EPA). 2014. Common Wastes & Materials-Scrap Tires-Basic information.

Wik, A. and G. Dave. 2005. Environmental labeling of car tires – toxicity to Daphnia magna can be used as a screening method. Chemosphere 58(5): 645-651.


Acetic acid/vinegar as pesticide ingredients

Acetic acid is one of the few chemicals with two common names. Both depend upon its concentration. “Vinegar” means concentrations up to 8%. “Acetic acid” means concentrations higher than 8%. When the concentration is low enough to be called vinegar, it is a food product. When the concentration is high enough to be called acetic acid, and it is used to kill weeds, it is a pesticide. The point to remember with acetic acid is that high concentrations are more effective on woody perennial weeds, while low concentrations will work effectively only on very young weed seedlings.


For more information on using acetic acid/vinegar as a pesticide, see WSU FS161E.

Submitted by: Catherine Daniels, March 9, 2015


Gardening in Washington State, Puyallup Research and Extension Center

All publications linked to this website have been peer-reviewed
© 2022 Washington State University | Accessibility | Policies | Copyright | Log in