Ornamental and Lawn Pest Control (For Homeowners) Oklahoma Cooperative Extension Service • Division of Agricultural Sciences and Natural Resources F-7306 Tom A. Royer Mike Schnelle Extension Entomologist Extension Ornamentals - Floriculture Specialist his fact sheet describes some common arthropod pest origin manufactured to kill pests – insects, weeds, plant problems encountered on various ornamentals and disease organisms, and rodents. Materials poisonous to one Tturfgrasses in Oklahoma. If arthropod pest problems form of life are usually poisonous to other forms if the dosage arise that are not covered here, consult your OSU County is large enough. Extension Center for assistance. Pesticides can be applied safely when a few basic rules Many of our arthropod pest problems are solved through are followed and common sense is used. Refer to OSU natural controls such as weather, other forms of plant and Extension Facts 7450, 7453, and 7454 for more information animal life, disease, parasites, and predators. When nature on pesticide safety. For information on insect control in the either does not solve the pest problem or is slow to act, other garden, refer to OSU Extension Facts 7313. controls may be warranted. Chemical pesticides often provide Note: Whenever possible, buy and grow pest resistant the quickest and most dependable control, and in many plants (such as Oklahoma Proven selections or other recom- instances, there are no other alternatives. mended varieties). By doing so, the need for pest control Pesticides are chemicals of plant, animal, or synthetic measures can be greatly reduced. Pests of Trees, Shrubs, and Flowers Pest Description & Damage Suggested Chemical Formulation and Comments (Approximate Sizes Mixing Instructions with Water Noted, See Picture) APHIDS Small, pear-shaped, soft-bodied, Bayer Advanced Garden Tree & Aphids secrete honeydew (1/8 - 1/5 in) sucking insects that cause leaves Shrub Insect Control (sticky, sugar-like substance), to curl (pucker). They are commonly diazinon - 2 tsp of 25% EC/gal * which may attract ants, flies, found on the underside of leaves. malathion - 2 tsp of 50% EC/gal provide media for sooty mold, Orthene - 2 tbs of 9.4% EC/gal and make spots on parked cars insecticidal soap - per label under infested plants. May neem - e.g. Bioneem or Neemisis - need to repeat applications per label at 7 to 10 day intervals. For small infestations, aphids can frequently be knocked from foliage with forceful water pressure from a hose. BAGWORM Larvae hatch from eggs that Bacillus thuringiensis - B.t. “bacterial NOTE: Control with B.t. often is slower Bagworm case (1-2 in) overwinter in old bags remaining insecticide” - Various trade names, than other insecticides. Apply chemical on the foliage from the previous year. use rates/mixing instructions on early while worms are small. Hand Larvae start to feed in late spring the label picking and destroying bags during (end of May to early June). Young Bayer Advanced Garden Tree & Shrub winter will help reduce bagworm worms spin silken sacs and attach Insect Control infestations the next season. Bagworms bits of leaves as they feed. diazinon - 2 tsp of 25% EC/gal * may be more common on deciduous malathion - 2 tsp of 50% EC/gal plants when evergreens are sprayed or Orthene - 3 tbs (1oz) of 9.4% EC/gal absent from the landscape. Sevin - 2 tbs of 50% WP/gal Liquid Sevin 27% - 1 tbs/gal BORERS (1/2 - 1 3/4 in) Flat- or round-headed borers (larvae) make tunnels Also see Comments column. [Help prevent borers Spray trunk or lower branches to point (e.g. flat-headed, round-headed wood under the bark. Shot-hole borers make pin-sized with proper timing or spray scheduling by killing of runoff. Cut and burn infested twigs borers, and shot-hole borers). holes in twigs or limbs and often the emergence adults before or during egg laying period(s); when possible. Water and fertilize trees. holes of adults make the bark appear as if pierced however, check the label before treatment to insure See OSU Fact Sheet 6412, “Fertilizing by shotgun pellets. Generally, trees in a state of the product can be used on the borer infested plants Shade and Ornamental Trees”; Fact decline or unhealthy state, often due to being you intend to treat. These treatments will not control Sheet 6409, “Pruning Ornamental Trees planted in tight or heavy soils, are more susceptible borers inside the plant.] and Shrubs”; and Fact Sheet 7315, to attack. Borer activity should not be confused with “Shade Tree Borers” for details. holes made by species of woodpeckers (refer to Fact Sheet 7315 for more information on borers). 7306 / 1 Oklahoma State University Pest Description & Damage Suggested Chemical Formulation and Comments (Approximate Sizes Mixing Instructions with Water Noted, See Picture) BOXELDER BUG / REDSHOULDERED Nuisance household pest in the fall. Feed on Bayer Advanced Lawn & Garden Multi- Treat ground cover and tree trunk when BUG boxelder, golden raintree, and soapberry, but don’t Insect Killer bugs are first seen (March, April, and (1/2-1 3/4 in) injure the tree. Avoid planting host trees in close diazinon 2 tsp of 25% EC/gal * September). Repeated treatments may proximity to house. Plug openings around windows Bug-B-Gon Multi-Purpose Insect Killer be required. and doors, and caulk small openings that can serve as points of entry. CATERPILLARS Larvae that feed on foliage. Some species roll and neem - e.g. Bioneem or Neemisis - per label Adequate pressure and volume for (e.g. webworms, tent caterpillars, tie with silk and some build webs or tents around Bacillus thuringiensis (B.t.) (bacterial spray needs to be applied to break up cankerworms, leafrollers / tiers, and foliage or in crotches of limbs insecticide, liquid, or WP for webworms, webbing or tents. Apply spray to the leafminers) (1/2 - 1 1/2 in) tent caterpillars, and cankerworms). point of runoff. Check product label Check label for rate. before use to insure it is labeled for the diazinon - 1-2 tbs of 25% EC/gal * plant and pest. NOTE: B.t. normally malathion 50% EC - 2tsp/gal stops worms from feeding, but has a Orthene - 3 tbs (1 1/2 oz) of 9.4% EC/gal delayed killing action. NOTE: Do not use Sevin - 2 tbs of 50% WP/gal or Orthene 9.4% EC on American elm, Liquid Sevin 27% - 1 tbs/gal redbud, flowering crabapple, sugar maple, or red maple. ELM LEAF BEETLE / WILLOW LEAF BEETLE Elm leaf beetles lay orange-yellow eggs on the Bayer Advanced Garden Tree & Shrub Elm leaf beetles mainly damage Siberian Adults (1/4 in) undersides of leaves in May or early June. Eggs Insect Control elms and Japanese zelcova. For best Larvae (1/4 - 3/8 in) hatch into larvae that does most of the damage by Orthene - 3 tbs (1 1/2 oz) of 9.4% EC/gal results, apply chemicals (except skeletonizing leaves. In Oklahoma, there are three Sevin - 2 tbs of 50% WP/gal Di-Syston) when the small larvae are first or four complete generations of elm leaf beetles per Liquid Sevin 27 % - 1 tbs/gal observed on the under- sides of leaves. year. Willow leaf beetle adults and larvae inflict Di-Syston granules for elm leaf beetles - the 15% In the early fall, adults migrate to homes similar damage to willows in May or early June. granules are restricted and can only be applied or buildings and crawl under shingles and by certified applicators. Homeowners may be into cellars, attics, or similar areas to able to find 2% granules. Apply granules during overwinter. NOTE: Do not use Orthene March and water immediately after application. 9.4% EC on American elm. Bacillus A second application in May will help control thuringiensis ‘strains’ are now available later generations of beetles. for control of some beetles. HOUSE PLANT PESTS Most of these pests suck plant fluids and cause leaf ready-to-use spray or aerosols that contain: Repeat applications may be needed at 5 (e.g. spider mites, mealy bugs, discoloration and leaf cupping/malformation. Fungus pyrethrins + piperonyl butoxide, tetramethrin to 7 day intervals. NOTE: Use caution fungus gnats, whiteflies, aphids, and gnat larvae attack roots. Allowing soil to dry + sumithrin, resmethrins, or rotenone or on young plants and new growth, and thrips - these pests may also be thoroughly between waterings often kills larvae. combinations of these. check label for plants that can be present on outdoor plantings.) NOTE: Alcohol soaked cotton swabs can also be treated. Sometimes light pest used to remove pests from house plants. infestations can be wiped from foliage insecticidal soap - per label directions is registered with mild detergent solutions (e.g. 2 tsp for control of many house plant pests. of detergent/gal of water). For neem products - per label nonpesticide methods of pest control on house plants refer to Fact Sheet 6411, “House Plant Care.” JAPANESE BEETLE Adult beetles have been consistently collected from Bayer Advanced Garden Rose and Flower Roses, crape-myrtle, apple, linden, and Adult (1/2 in) a few locations in the state. Adult beetles feed on - 1 tbs/gal hibiscus are most susceptible to Larvae (1/2 in) foliage and fruits of many plants and the larvae feed Sevin - 1 1/2 - 2 tbs of 50% WP/gal feeding. on turf much like other white grubs. Adults are active malathion - 2 tsp of 50% EC/gal from late June through July. MAY / JUNE BEETLES Adults of white grubs sometimes feed on leaves of Sevin - 2 tbs of 50% WP/gal Trees growing close to street or yard (1/2 - 3/4 in) American elm and a few other trees. diazinon - 2 tsp of 25% EC/gal * lights are generally most attractive to the beetles or areas where soil contains a high amount of organic matter.