[Technically Speaking] So many questions - Still few answers

In October I attended the NPMA Convention in Dallas. Other than wanting to learn about new products and visit with many friends I was looking forward to the many presentations on bed bugs. I wanted to find the answers to the many questions regarding the most effective products and formulations, the most effective control strategies, etc. Unfortunately, I came away with very few answers.

This is not a criticism — there are many researchers working diligently to find these answers — but it takes time. Their research had to start from scratch about five years ago and at the time to the best of my knowledge the only person in the United States who had a bed bug colony that could serve as the "normal strain" was Dr. Harold Harlan. Another factor in bed bug research is that they are not easy to colonize. While they have a biotic potential comparable to German cockroaches their feeding habits (blood) and sensitivity to environmental conditions make it much harder to acquire the numbers necessary to perform insecticide susceptibility and resistance tests. Yes, I said resistance.

The following is a brief synopsis of the bed bug presentations I attended:

DR. DINI MILLER, VIRGINIA TECH

• Bed bug sniffing dogs can’t distinguish between live and dead bugs.

• Confining field-collected bed bugs on treated panels until 100% mortality:

u Demand: 1 hour, 18 minutes

u Tempo: 12 hours, 10 minutes

u Talstar: 3 days, 16 hours

u Suspend SC: 19 days, 2 hours

u Phantom and NIC were much
slower than the above products

• Repellency — bed bugs do not acknowledge products at all

• Gentrol caused 43% mortality but no reduction in egg production and hatch.

• Summary: Results indicated significant resistance in field strain when compared to "normal" strain — possibly the result of previous exposure to cyclodienes and chlorinated hydrocarbons, e.g., DDT, and preventive applications won’t help much.

DR. KATHY HEINSOHN, NPMA

• Thermal death = 45°C

• Heat = 120°F for three to four hours

• Cold = 0°F for four to seven days

• Steam = use the large nozzle 1½ inches from surface. Dry steam = instantaneous death.

DR. MIKE POTTER, UNIVERSITY OF KENTUCKY

• Vacuuming not effective in removing bed bugs from cracks and eggs stick to surfaces and are hard to remove.

• Steam very effective with larger head on nozzle. Don’t use the smaller head — it will blow eggs and bed bugs all over the place.

• Use black trash bags in sunlight for thermal kill.

• Normal wash cycle will kill bed bugs.

• Running clothes through the drier for five minutes kills everything.

• Encasement is effective in preventing biting. Some question as to whether bugs will bite through fabric covers.

• Sofas and other upholstered items can be trashed or treated.

• Summary: Some non-chemical methods work very well but have limited applications. Relying on a tenant to wash and/or dry all potentially infested items is not effective.

DR. KEN HAYNES, UNIVERSITY OF KENTUCKY

• 90% of bed bug life is spent in harborage where mating typically occurs.

• For a few hours every day bed bugs venture out seeking food.

• They are more active late at night.

• Heat is a very important element influencing behavior.

ALVARO ROMERO, UNIVERSITY OF KENTUCKY

• Suspend and Demand provided very low mortality in field-collected strains sprayed directly with the products.

• Only 5% mortality occurred in one field collected strain exposed to pesticide on paper for 24 hours — 300 times the rate of normal application. Other tests indicated Demand caused 35% and 39% mortality on paper and wood respectively.

• Demand caused 43.4% mortality of newly emerged nymphs after 13 days.

• Deltamethrin caused two out of three nymphs to avoid treated harborages.

• Crossing the "normal" strain with the field collected strain produced 62% mortality at 100x rate of normal application.

• Summary: Suspect resistance if you observe bed bugs sitting on treated surfaces. Bed bug infestations are difficult to eliminate.

RALPH CITARELLA, BAYONNE EXTERMINATING CO., BAYONNE, N.J.

• Typically three treatments are needed with two technicians.

• Treatments are scheduled at three-week intervals based on life cycle of 21 to 28 days.

• Charge by the number of bedrooms. One bedroom typically requires 45 minutes.

• The company provides a close-ended six-month warranty (contingent on tenant preparation and follow-up) with upfront pricing and free callbacks within warranty period. Offer elimination, not relief.

• Summary: Budget enough time to perform thorough treatments and charge accordingly. Treatments should be spaced adequately apart to kill newly emerging nymphs.

MY THOUGHTS. Here’s what I think as a result of hearing all of these presentations:

• Lab results indicate that products we currently have available are not providing more than 50% mortality as residuals and as direct contact insecticides.

• Field experience in thousands of apartments indicates we are getting good control (not necessarily elimination) with the products we have available if:

u Tenants prepare and follow through on laundering potentially infested items.

u We make voluminous applications (hose it down — at least 1 to 2 gallons/unit).

u We make thorough applications (not a hunt and peck treatment) to all conceivable cracks and crevices, particularly around carpet tack, walls and closets. (A thorough treatment to the bed goes without saying.)

u We typically make at least three applications at 10 to 14 day intervals.

• Do not guarantee anything (except perhaps private residences). We do not control the environment, we do not control reintroduction, we do not control the bedding, clothes and clutter, we do not have products that perform similar to those of the past, and we do not control bed bugs’ behavior and physiology.

The author is president of Innovative Pest Management, Brookeville, Md. He can be reached at rkramer@giemedia.com.