You are here.
Elm
Bark Beetles: Formulations of azadirachtin (Ornazin 3% EC only), bifenthrin (Onyx Insecticide only), carbaryl, chlorpyrifos (Dursban 50W only), lambda-cyhalothrin (only Warrior with Zeon Technology for European elm bark beetle), permethrin (Astro Insecticide and Permethrin Pro only), and pyrethrins and piperonyl butoxide are labeled for bark beetle management. A 2(ee) recommendation for Mavrik Aquaflow Insecticide is in place for the control of elm bark beetles in trees and shrubs within the states of Pennsylvania (and New Jersey). The 2(ee) recommendation for Mavrik Aquaflow Insecticide states that it is for application only under the recommendation and supervision of a Certified Arborist. Lambda-cyhalothrin (only Warrior with Zeon Technology) is labeled for European elm bark beetle management. The use of elm bark beetle pheromone traps may assist in the timing of spray applications. Make applications against the native elm bark beetle during April and against the smaller European elm bark beetle in the spring and summer according to label directions, to reduce adults before they mate and lay eggs.
Management Hints: Fertilization and irrigation will promote a healthy plant. Prune and destroy weak, dead branches and trees as soon as noticed. This is one effective method of reducing the spread of Dutch elm disease to healthy trees. Spraying offers some additional protection but is suggested only for valuable trees. (pp. 246, 248)
Calico Scale: Horticultural spray oil can be applied as a dormant treatment. Crawlers may be managed with formulations of acephate, azadirachtin (Ornazin 3% EC only), buprofezin, carbaryl, chlorpyrifos (Dursban 50W only), cyfluthrin, cyfluthrin and imidacloprid, deltamethrin, dinotefuran, horticultural oil, hydrophobic extract of neem oil, imidacloprid, insecticidal soap, lambda-cyhalothrin (Battle GC, Demand CS, Scimitar CS, Scimitar GC, and Scimitar WP only), methidathion, and thiamethoxam. Marathon 1% G and Marathon 60 WP are labeled for use only on plants grown in containers, flats, benches, or beds.
Management Hints: Select and apply horticultural spray oils according to label directions. Crawlers may be managed when they are active in June through early July. Repeat applications may be needed. (p. 354)
Cankerworm: 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), cyfluthrin, cyfluthrin and imidacloprid, deltamethrin, diflubenzuron, lambda-cyhalothrin (Battle GC, Demand CS, Scimitar CS, Scimitar GC, and Scimitar WP only), naled, permethrin (Astro Insecticide and Permethrin Pro only), phosmet (spring cankerworm only), pyrethrins and piperonyl butoxide, spinosad, tau-fluvalinate, and tebufenozide (fall cankerworm only) are labeled for cankerworm management.
Management Hints: Apply when small larvae are active in May. (pp. 142, 144)
Elm Leaf Aphids: Horticultural spray oil can be applied as a dormant treatment. Formulations of abamectin, acephate, acetamiprid, azadirachtin, Beauveria bassiana, 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), cyfluthrin, cyfluthrin and imidacloprid, deltamethrin, dinotefuran, disulfoton, fenpropathrin, horticultural oil, hydrophobic extract of neem oil, imidacloprid, lambda-cyhalothrin (Battle GC, Demand CS, Scimitar CS, Scimitar GC, and Scimitar WP only), malathion, naled, oxydemeton-methyl, permethrin (Astro Insecticide and Permethrin Pro only), pymetrozine, pyrethrins and piperonyl butoxide, pyriproxyfen, tau-fluvalinate, and thiamethoxam are labeled for aphid management. Marathon 1% G and Marathon 60 WP are labeled for use only on plants grown in containers, flats, benches, or beds.
Management Hints: Select and apply horticultural spray oil according to label directions. Treat when aphids are first noticed in the spring. Repeat insecticide applications as needed. Malathion may cause slight damage to elms. (p. 306)
Elm Leaf Beetle: Formulations of acephate, azadirachtin, 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), cyfluthrin, cyfluthrin and imidacloprid, deltamethrin, disulfoton, horticultural oil (larvae only), imidacloprid, insecticidal soap (M-Pede only to manage larvae), lambda-cyhalothrin, naled, oxydemeton-methyl, phosmet (larvae only), pyrethrins and piperonyl butoxide, spinosad (adults and larvae), and taufluvalinate are labeled for beetle management. Marathon 1% G and Marathon 60 WP are labeled for use against elm leaf beetles only on plants grown in containers, flats, benches, or beds.
Management Hints: Apply materials from late May through June and in July. (p. 222)
Elm Spanworm: Formulations of acephate (Turf, Tree, and Ornamental Spray only), 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 (Battle GC, Demand CS, Scimitar CS, Scimitar GC, and Scimitar WP only), permethrin (Astro Insecticide and Permethrin Pro only), phosmet, pyrethrins and piperonyl butoxide, tau-fluvalinate, and tebufenozide are labeled for management of this pest.
Management Hints: Apply when small larvae are active in mid- to late May. (pp. 144, 146)
European Elm Scale: Horticultural spray oil can be applied as a dormant treatment. Formulations of acephate, azadirachtin (Ornazin 3% EC only), buprofezin, carbaryl, chlorpyrifos (Dursban 50W only), cyfluthrin, cyfluthrin and imidacloprid, deltamethrin, dinotefuran, disulfoton, horticultural oil, hydrophobic extract of neem oil, imidacloprid, insecticidal soap, lambda-cyhalothrin (Battle GC, Demand CS, Scimitar CS, Scimitar GC, and Scimitar WP only), methidathion, oxydemeton-methyl, and thiamethoxam are labeled for crawler management. Marathon 1% G and Marathon 60 WP are labeled for use only on plants grown in containers, flats, benches, or beds.
Management Hints: Select and apply horticultural spray oil according to label directions. Crawler sprays should be applied in late June through mid-July. (p. 368)
Fall Webworm: Refer to comments under Crabapple (ornamental nonedible flowering).
Management Hints: Treat when webs are small in late June through July. Acephate is labeled to manage fall webworm on elm. (p. 166)
Japanese Beetle: Formulations of acephate, acetamiprid, azadirachtin, 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), cyfluthrin, cyfluthrin and imidacloprid, deltamethrin, dinotefuran, fenpropathrin, imidacloprid, lambda-cyhalothrin, malathion, permethrin (Astro Insecticide and Permethrin Pro only), phosmet, and pyrethrins and piperonyl butoxide are labeled for management of adults. Formulations of imidacloprid (Merit 2, Merit 75 WP, and Merit 75 WSP) are also labeled for management of white grub larvae such as Japanese beetle, chafers, Oriental beetle, Asiatic garden beetle, and Phyllophaga spp. Marathon 1% G and Marathon 60 WP are labeled for use only on plants grown in containers, flats, benches, or beds. Merit 2.5 G is labeled for use on ornamental shrubs and small trees in outdoor landscapes and interior plantscapes against Japanese beetle adults.
Management Hints: Apply when adults are active from late June through July. (p. 236)
Leafhoppers: Formulations of acephate, acetamiprid, azadirachtin, 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, disulfoton, fenpropathrin, hydrophobic extract of neem oil, imidacloprid, insecticidal soap, lambda-cyhalothrin (Battle GC, Demand CS, Scimitar CS, Scimitar GC, and Scimitar WP only), malathion, permethrin, phosmet, pyrethrins and piperonyl butoxide, tau-fluvalinate, and thiamethoxam are labeled for management of leafhoppers.
Management Hints: Treat when leafhoppers are first seen. Repeat treatment according to label directions. Malathion may cause slight damage to elms. (pp. 412, 414, 416)
Spiny Elm Caterpillar: Formulations of azadirachtin, 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, cryolite, cyfluthrin, cyfluthrin and imidacloprid, lambda-cyhalothrin (Battle GC, Demand CS, Scimitar CS, Scimitar GC, and Scimitar WP only), permethrin (Astro Insecticide and Permethrin Pro only), pyrethrins and piperonyl butoxide, and tau-fluvalinate are labeled for caterpillar management.
Management Hints: Apply when caterpillars are small from mid- to late July. (p. 152)
Whitemarked Tussock Moth: Formulations of azadirachtin, 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-cyfluthrin, permethrin (Astro Insecticide and Permethrin Proonly), pyrethrins and piperonyl butoxide, spinosad, and tau-fluvalinate are labeled for management of this pest.
Management Hints: This insect may produce two or three generations each year. Treat foliage when larvae are first seen in late May. Naled is labeled for tussock moth management on elm.Repeat applications when necessary. (p. 158)
Yellownecked Caterpillar: Formulations of azadirachtin, 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, lambda-cyhalothrin (Battle GC, Demand CS, Scimitar CS, Scimitar GC, and Scimitar WP only), permethrin (Astro Insecticide and Permethrin Pro only), pyrethrins and piperonyl butoxide, spinosad, and tau-fluvalinate are labeled for management of this pest.
Management Hints: Applications may be made from July through mid-September when larvae are present and infestations are severe. Buds are usually set on host plants late in the growing season so that lowering population levels will be more aesthetic in nature than for plant health care reasons. Remove and destroy colonies of young larvae when observed on the foliage of trees. (p. 154)