caa a22 4500 386361282 CHVBK 20180307111916.0 cr unu---uuuuu 161130e198903 xx s 000 0 eng 10.4039/Ent121219-3 doi S0008347X00028649 pii (NATIONALLICENCE)cambridge-10.4039/Ent121219-3 PYRETHROID RESISTANCE IN PEAR PSYLLA, PSYLLA PYRICOLA FOERSTER (HOMOPTERA: PSYLLIDAE), AND SYNERGISM OF PYRETHROIDS WITH PIPERONYL BUTOXIDE [Elektronische Daten] Adult pear psylla, Psylla pyricola Foerster, from commercial pear orchards near Wenatchee, WA, were tested using a slide-dip technique for susceptibility to fenvalerate over a 5-year period from 1984 to 1988. Results were compared with those from similar tests using psyllids from an unexposed population near Corvallis, OR. During 5 years, resistance of adults to fenvalerate increased by 16- to 32-fold at Wenatchee while that of the Corvallis population did not change. In 1988, tests with five pyrethroids and pyrethroid - piperonyl butoxide combinations indicated that pear psylla adults also were resistant to permethrin and flucythrinate but not to fenpropathrin or cyfluthrin which contain a cyano group that reduces their susceptibility to oxidase metabolism. Piperonyl butoxide synergism was proportional to the level of resistance, indicating that resistance is probably due to increased mixed function oxidase activity. Implications of this study to control of post-diapause winter form adults in commercial pear orchards is discussed. Copyright © Entomological Society of Canada 1989 Burts Everett C. Washington State University, Tree Fruit Research and Extension Center, Wenatchee, Washington, USA 98801 van de Baan Hugo E. Department of Entomology, Oregon State University, Corvallis, Oregon, USA 97331 Croft Brian A. Department of Entomology, Oregon State University, Corvallis, Oregon, USA 97331 The Canadian Entomologist Cambridge University Press 121/3(1989-03), 219-223 0008-347X 121:3<219 1989 121 TCE https://doi.org/10.4039/Ent121219-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.4039/Ent121219-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Burts Everett C. Washington State University, Tree Fruit Research and Extension Center, Wenatchee, Washington, USA 98801 NATIONALLICENCE 700 1- van de Baan Hugo E. Department of Entomology, Oregon State University, Corvallis, Oregon, USA 97331 NATIONALLICENCE 700 1- Croft Brian A. Department of Entomology, Oregon State University, Corvallis, Oregon, USA 97331 NATIONALLICENCE 773 0- The Canadian Entomologist Cambridge University Press 121/3(1989-03), 219-223 0008-347X 121:3<219 1989 121 TCE CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge