Technically Speaking - Richard Kramer: Planning for the Fall Invasions

Several months ago I wrote a column discussing my frustration over the difficulty in characterizing Integrated Pest Management (IPM) for our industry. A pest management professional from Florida took exception with my use of the term "baseboard jockey." (See PCT Backtalk, July, page 12.)

I agree that pest pressures in subtropical environments are far greater than those in more northern areas and preventive applications may be necessary to prevent pest problems. What I disagree with is the indiscriminate use of pesticides as a matter of course as opposed to need.

I think the reader missed the mark on four points:

• I started my pest management career in Florida during the early 1960s when I obtained my driver’s license and was able to drive a service vehicle.

• I received all of my formal entomology education (nine years) at the University of Florida.

• I fully appreciate the pest problems in Florida. I always have strongly supported the responsible use of pesticides by our industry and will continue to do so.

• As you can tell from the remainder of this article, those of us further to the north use preventive pesticide applications to address pest problems as well.

The decision to use preventive pesticide applications should be based on experience and/or pest pressure, not a schedule. Thus, some thought must be given to each pest management situation, and the decision to spray should not be based on a set schedule.

There are a number of pests that invade structures in the fall seeking places to overwinter, such as lady bugs, crickets, boxelder bugs and cluster flies. The key to managing these pest problems is to prevent entry. Once these insects have entered the structure and found suitable harborage they are very difficult, if not impossible, to eradicate and they will periodically enter the structure throughout the winter months.

Typically the IPM approach to managing this type of pest is mechanical exclusion, e.g., caulking, sealing, etc. While this provides long-term solutions, it is time consuming, costly to the customer, and the likelihood of total success at best is remote. The reason for this is that these insects persistently seek the tiniest gaps in the building envelope to gain entry and survive the winter. This is not to say that exclusion should not be performed but it should not be relied on solely to prevent the problem.

PREVENTIVE APPLICATIONS. In my experience, I have found that preventive pesticide applications are a more economical approach to this problem and if timed correctly have a greater chance of success. Preventive pest management strategies that have proven successful include:

Exclusion — Prevent entry into buildings by sealing and caulking gaps around siding, windows, doors, pipes, wires, etc. To be effective, this work should be completed by early August. Sealing similar areas on the inside of the structure prevents pests from entering the interior from wall voids and voids between floors. Ensure that screens fit tightly and unscreened doors and windows are not left open. Screen soffit and ridge vents, which are also points of entry.

Indoors — Vacuuming will remove accessible invading insects. Tape and dispose of the vacuum bag. Light traps can be used effectively in some situations to reduce indoor infestations. Spraying indoors is of no value and provides little relief from the problem.

Cluster Flies — Cluster flies can’t be controlled by disrupting the life cycle of the larvae (maggots) because they are parasitic on earthworms, which are beneficial contributors to the environment. Residual applications of microencapsualted and wettable powder formulations can, however, be applied in the fall to the exterior surfaces of structures in order to control these flies prior to entry. Concentrate efforts on southern and western exposures.

Boxelder Bugs — Microencapsulated and wettable powder products are the most effective formulations for outdoor application sites. Apply these products as a six- to eight-foot band around the perimeter of the structure and/or around potential entry points. Timing of this application is critical, e.g., in Northeast states; mid- to late August is the ideal treatment time.

Field Crickets — Baits are effective when applied outdoors, as a band around structures and/or directly into harborage areas. Microencapsulated, wettable powder and granular products are the most effective formulations in the moist habitats preferred by crickets. Apply these products as a 6- to 8-foot band around the perimeter of the structure, into cricket harborage sites and/or around potential entry points.

Lady Bugs — Periodic inspection of exterior plants for aphids, scales and other soft-bodied insects helps to anticipate the problem. Preferably, these plants can be treated with a systemic insecticide or a topical formulation to control ladybug prey and minimize their interest around the structure. Avoid spraying if any of the beetle life stages are present. In the fall preventive applications should be made to the south and west walls as previously described.

A FEW HELPFUL POINTERS. Below are a few tips that may help your pest control service:

• There is added value in using pyrethroid formulations, most of them kill as well as repel the target pests.

• Be cautious when applying microencapsulated insecticides around windows; they may cause spotting. The spots can be removed but it takes time.

• Granular formulations work exceptionally well for ground-infesting invaders, such as centipedes, millipedes, ground beetles, sowbugs and crickets. Don’t forget they are not activated until they are wetted.

Always monitor your customer records to determine if they have a recurrent problem with fall invaders. If preventive applications are to be successful they must be timed correctly.