Nursery and Landscape - Insect Control Basics

The following are are some insect control basics for nurseries and landscapes.

There is no simple magic formula for pest control on trees and shrubs. More than 250 species of insects and mites are commonly found which damage or are potentially injurious to over 100 genera of woody ornamentals. Great diversity by insects in host preferences, seasonal development, periods of activity, habits, and susceptibility to insecticides requires careful planning and critical timing of control measures. It is a simple fact that insects and mites will occur, multiply, and cause serious losses if ignored or inadequately controlled.

The most frequent cause of insect problems is the failure of nurserymen and landscapers is to carry out necessary control procedures properly at the right time due to pressures from other phases of production and maintenance. The consequence, without exception, is a much more difficult and costly situation.

The best way to control insects and mites is a preventive program. First, do not introduce pest problems. In nursery production, propagate or buy ONLY clean, uninfested stock plants. In municipal tree plantings or private landscaping, set out ONLY insect-free plant materials. The presence of a few hardly noticeable insects or mites at planting time is a sure source of extra work and costly effort later on. Second, draw up a seasonal pest monitoring schedule to prevent the establishment and buildup of insects and mites. Third, maintain regular surveillance of established plant materials and be prepared to schedule control measures for difficult or complex pest problems which arise.

Take advantage of assistance from your local Extension agent and the Extension specialists at the University of Delaware. Sussex - Tracy Wooten (302) 856-7303; Kent - Gordon Johnson (302) 730-4000; New Castle - Carrie Murphy (302) 831-1426.

Information take from the Virginia Pest Management Guide, Nursery Insect section by Peter B. Schultz, Extension Entomologist, Hampton Roads AREC, and Eric R. Day, Extension Entomologist, Virginia Tech.

Landscape - Pest Proofing

Fall is the time of year that many clients complain about insects and other pests entering homes and other structures from the landscape. Landscape maintenance firms may wish to add pest proofing to their business portfolio. The following is more information.

Outlined below are six tips for pest proofing a home or business. Steps 1-3 will also conserve energy and increase the comfort level during winter and summer. Equipment and materials can be purchased at most hardware or home improvement stores.

Install door sweeps or thresholds at the base of all exterior entry doors. Lie on the floor and check for light visible under doors. Gaps of 1/16" or less will permit entry of insects and spiders; 1/4"-wide gaps (about the diameter of a pencil) are large enough for entry of mice; ½" gaps are adequate for rats. Pay particular attention to the bottom corners as this is often where rodents and insects enter. Garage doors should be fitted with a bottom seal constructed of rubber (vinyl seals poorly in cold weather). Gaps under sliding glass doors can be sealed by lining the bottom track with ½ to 3/4 inch-wide foam weather stripping. Apply sealant along bottom outside edge and sides of door thresholds to exclude ants and other small insects.

Seal utility openings where pipes and wires enter the foundation and siding, such as around outdoor faucets, receptacles, gas meters, clothes dryer vents, and telephone/cable TV wires. These are common entry points for ants, spiders, wasps, rodents and other pests. Holes can be plugged with mortar, caulk, urethane expandable foam, copper mesh (like the material in pot scrubbers), or other suitable sealant.

Seal cracks around windows, doors, fascia boards, etc. Use a good quality silicone or acrylic latex caulk/sealant. Although somewhat less flexible than pure silicone, latex-type caulks clean up easily with water and can be painted. Caulks that dry clear are often easier to use than pigmented caulks since they don't show mistakes. Buy a good caulking gun. Features to look for include a back-off trigger to halt the flow of caulk when desired, a built-in 'slicer' for cutting the tip off of new caulking tubes, and a nail for puncturing the seal within. Hardware stores sell caulking guns with these features for less than $10.00. Prior to sealing, cracks should be cleaned and any peeling caulk removed to aid adhesion. For a professional look, smooth the bead of caulk with a damp rag or a moistened finger after application. A key area to caulk on the inside of basements is along the top of the foundation wall, where the wooden sill plate is attached to the concrete foundation. Ants, spiders, and other pests often enter through the resulting crack.

Repair gaps and tears in window and door screens. Doing so will help reduce entry of flies, gnats, mosquitoes and midges during summer, and cluster flies, lady beetles, and other overwintering pests in autumn. Certain insects are small enough to fit through standard mesh window screen. The only way to deny entry of these tiny insects is to keep windows closed during periods of adult fall emergence.

Install 1/4-inch wire mesh (hardware cloth) over attic, roof, and crawl space vents in order to prevent entry of birds, bats, squirrels, rodents, and other wildlife. Be sure to wear gloves when cutting and installing hardware cloth as the wire edges are razor sharp. Backing the wire mesh from the inside with screening will further help to prevent insects such as ladybugs, paper wasps and yellowjackets. If not already present, invest in a chimney cap to exclude birds, squirrels, raccoons and other nuisance wildlife. Raccoons, in particular, are a serious problem throughout Kentucky. Many chimneys become home to a family of raccoons which, in turn, are often infested with fleas.

Consider applying an exterior (barrier) insecticide treatment. While sealing is the more permanent way to exclude pests originating from outdoors, comprehensive pest-proofing is laborious and sometimes impractical. For clients needing an alternative, pest proofing can be supplemented by an exterior treatment with an insecticide. Use recommended insecticides for exterior treatments and treat at the base of all exterior doors, garage and crawl space entrances, around foundation vents and utility openings, and up underneath siding. It also may be useful to treat around the outside perimeter of the foundation in a 2 to 6-foot-wide band along the ground, and 2-3 feet up the foundation wall.

Adapted from "TIME TO PEST-PROOF YOUR HOME" By Mike Potter in the September 15 edtition of the Kentucky Pest News from the University fof Kentucky, Colleger of Agriculture. http://www.uky.edu/Ag/kpn/kpn_08/pn080915.htm#houtim

Landscape - Time to Look At Landscapes and Evaluate

With the recent hot and humid weather, many diseases are present in the landscape. In addition, early summer brings many different insect and mite pests. Landscape professionals should take time to visit some landscapes and evaluate plantings for problems as well as noting problem free plants. Some thoughts:

• Check common problem plants and areas that have had issues in the past. South sides of buildings, exposed areas, and areas that recieve a lot of stress are candidates for many insect and mite pests.
• Brown patch will be showing up in untreated lawns, especially those that are heavily fertilized.
• Foliar diseases such as powdery mildew will be common, especially in areas that are shaded or that stay continually moist.
• Many scales are in active crawler stages. Check plants that had scale problems in the past and apply controls
• Japanese beetles are very active and can cause damage very quickly to susceptible plants.
• Look for those plants with little or no disease or insect problems and that handle stress well. Make lists of these plants and consider ways to use them in upcoming projects. The best way to reduce maintenance such as spraying pesticides is to use trouble free plants. Clients will also be more satisfied with their landscapes.
• Look for plants in decline as a result of long-term stresses, especially from last year's drought. Consider replacements.

Gordon Johnson, Extension Horticulture Agent, UD, Kent County

Landscape - Neonicotinoid Insecticides for Systemic Insect Control in the Landscape

The neonicotinoid insecticides have been extremely useful for control of hard to kill insects in the landscape such as scales, adelgids, leaf miners, and mealybugs. The following are some slides on the use of these insecticides as systemic treatments in the landscape.

Click on a Slide for a larger image

From a presentation by Casey Sclar, Ph.D. – Plant Health Care Division Leader, Longwood Gardens, Inc. Kennett Square, PA

Greenhouse - Insect Management

Insects can easily build up in greenhouses due to the perfect growth environment. The following are some thoughts on managing insects in greenhouse production.

Starting clean

Do not carry-over insects from one crop to another. Keep thrips numbers down to less than 10 per card per week in the fall and winter on poinsettias and Dracaena. Avoid keeping houseplants or allowing weeds to grow in the greenhouse. When each batch of media arrives for a new crop, check it for fungus gnats by filling a 1 gallon ziplock bag half full with moist soil. If fungus gnat adults emerge within 2 weeks, consider applying a fungus gnat treatment at planting time. Check incoming plant material carefully for insects.

Scouting

Monitor thrips and whiteflies with yellow sticky cards. Change cards once per week. Use at least one card per house or one per 2,000 sq ft. Check the first plants that flower for thrips. For spider mites and aphids, check susceptible plants like marigolds (mites) and peppers (aphids), weekly. Potato wedges can be stuck in soil and checked 24 hours later for fungus gnat larvae. Systemic insecticidesUse Marathon, Tristar, Flagship, Safari or Aria in poinsettia pots, lily pots or in hanging baskets prone to problems with whiteflies, aphids, mealybugs or soft scales. Note: Aria does not work on silverleaf whitefly.

Preventing outbreaks

If yellow sticky cards or scouting indicates an increase in aphids, mites, thrips, fungus gnats or whiteflies, apply the following materials once per week until populations decrease to acceptable levels.

Thrips - Avid, Conserve, Mesurol, Orthene 97, Safari, Sanmite, Tristar.
Aphids - Aria, BotaniGard, Decathlon, Discus, Endeavor, Flagship, Marathon, Orthene 97, Precision, Safari, Talstar, Tristar.
Whiteflies - Azatin, BotaniGard, Decathlon, Distance, Endeavor, Enstar, Flagship, Marathon, Ornazin, Orthene 97, Precision, Safari, Sanmite, Talus, Judo, Tame, Tristar (Note: Q biotype may be resistant to Marathon, Flagship, Tristar, Safari, Distance and Talus).
Mites - Akari, Avid, Floramite, Hexygon, Judo, Ovation, Pylon, Sanmite, Shuttle, Tetrasan, Ultiflora.
Broad mites - Avid, Akari, Judo, Pylon, SanMite.
Fungus gnat (drenches) - Azatin XL, Adept (not on poinsettias), Distance, Marathon (perhaps other nicotinoids; not yet tested), Mesurol.
Mealybugs/ Soft scales - Aria, Flagship, Orthene, Safari, Talus and Tristar.

From the article "Greenhouse insect management" by Dave Smitley, MSU Entomologist, in the January 19, 2007 edition of the Greenhouse Alert newsletter from Michigan State University Extension