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Douglas-Fir
Bagworm: Formulations of acephate, azadirachtin, Bacillus thuringiensis, bifenthrin (Bifenthrin Pro Multi-Insecticide, Onyx Insecticide, Talstar F, Talstar Lawn & Tree Flowable, Talstar GC Flowable, Talstar Nursery Flowable, and TalstarOne Multi-Insecticide only), carbaryl, chlorpyrifos (Dursban 50W only), cryolite, cyfluthrin, cyfluthrin and imidacloprid, deltamethrin, diflubenzuron, lambda-cyhalothrin, malathion, permethrin, pyrethrins and piperonyl butoxide, spinosad, tau-fluvalinate, tebufenozide, and trichlorfon are labeled for bagworm management.
Management Hints: Bagworm cases (containing overwintering eggs) can be handpicked from infested host plants during winter and early spring. Otherwise, management measures can be applied after eggs hatch and caterpillars are small during early to mid-June. (p. 176)
Cooley Spruce Gall Adelgid: Horticultural spray oil can be applied as a dormant treatment; however, horticultural oil may injure Douglas-fir fl ower buds. Formulations of acetamiprid, bifenthrin (Bifenthrin Pro Multi-Insecticide, Talstar F, Talstar Lawn & Tree Flowable, and TalstarOne Multi-Insecticide only), carbaryl, chlorpyrifos (Dursban 50W only), cyfluthrin and imidacloprid, deltamethrin, horticultural oil, imidacloprid, insecticidal soap, oxydemeton-methyl, and tau-fluvalinate are labeled for adelgid management. Marathon 1% G and Marathon 60 WP are labeled for use only in plants grown in containers, flats, benches, or beds.
Management Hints: Apply horticultural spray oil according to label directions. Apply materials before buds break in April. Adelgids can be managed on Douglas-fir in the summer months, but results obtained seldom reach optimum levels. To manage overwintering adelgids, apply a registered material from mid-September through October. (p. 112)
Pine Needle Scale: Crawlers may be managed with formulations of acephate, acetamiprid, azadirachtin (Ornazin 3% EC only), bifenthrin (Bifenthrin Pro Multi-Insecticide, Onyx Insecticide, Talstar F, Talstar Lawn & Tree Flowable, Talstar GC Flowable, Talstar Nursery Flowable, and TalstarOne Multi-Insecticide only), buprofezin, carbaryl, chlorpyrifos (Dursban 50W only), cyfluthrin, cyfluthrin and imidacloprid, deltamethrin, dinotefuran, horticultural oil, hydrophobic extract of neem oil, insecticidal soap, lambda-cyhalothrin (Battle GC, Demand CS, Scimitar CS, Scimitar GC, and Scimitar WP only), malathion, methidathion, and oxydemeton-methyl (on field-grown nursery stock).
Management Hints: Apply horticultural spray oil according to label directions. Please note that oil may injure Douglas-fir flower buds. Crawlers may start to emerge from eggs during late April through May. Emergence of second generation crawlers will occur during mid- to late July. Crawler activity will vary from year to year due to climatic conditions. To obtain maximum control, monitor infested trees on a regular basis. Two applications of a registered insecticide may be necessary to manage heavy populations. Be aware that the adult female has a fairly long egg-laying period, and newly hatched crawlers may remain beneath the protective scale cover, especially on overcast days. (p. 108)
Spruce Spider Mite: Horticultural spray oil can be applied as a dormant treatment. Oil may injure Douglas-fir flower buds. Formulations of abamectin, bifenazate, bifenthrin (Bifenthrin Pro Multi-Insecticide, Onyx Insecticide, Talstar F, Talstar Lawn & Tree Flowable, Talstar GC Flowable, Talstar Nursery Flowable, and TalstarOne Multi-Insecticide only), chlorpyrifos (Dursban 50W only), deltamethrin, dicofol, disulfoton, etoxazole, fenbutatin-oxide, fenpyroximate, hexythiazox, horticultural oil, hydrophobic extract of neem oil, insecticidal soap, lambda-cyhalothrin (Battle GC, Demand CS, Scimitar CS, Scimitar GC, and Scimitar WP only), malathion, oxydemeton- methyl, spinosad, spiromesifen, and tau-fluvalinate are labeled for mite management.
Management Hints: Select and apply horticultural spray oil according to label directions. Apply registered materials to destroy mites hatching from eggs. This will occur from May through June. Additional generations may need to be managed in September through early October. If repeat applications are needed, follow label directions. (p. 118)
White Pine Weevil: Formulations of bifenthrin (Onyx Insecticide, Talstar GC Flowable, and Talstar Lawn & Tree Flowable only), chlorpyrifos (Dursban 50W only), and pyrethrins and piperonyl butoxide (Pyrenone Crop Spray) are labeled for weevil management. Naled (Dibrom 8) is labeled for pine weevil management on Douglas fir. Oxydemeton-methyl (Metasystox-R) is labeled for management of white pine weevil on field grown nursery stock. Diflubenzuron is not labeled for application to Douglas-fir.
Management Hints: To manage egg-laying weevils, apply a registered formulation to only the top of the host tree (terminal) as weather warms during late March through April. Timing can vary since conditions change from year to year. (p. 54)