[Technically Speaking] Answers to the question ‘Why?’ aren’t always easy

Anyone who has children has had to wrestle with the incessant question, "Why?" "Why mommy?" "Why daddy?" This often garners the response, "Because I said so." Even our customers have developed this behavior when asking about their pest problems.

Some of the recent why questions I have encountered include:

• Why are the millipedes/earwigs so bad this year?

• Why are lady bugs, wasps and boxelder bugs in my house in mid-winter?

• Why are ground beetles and springtails being found on upper floors?

• Why has the rat problem in the city gotten worse?

• Why is the mouse problem in our office building getting worse?

• Why has the cockroach problem in my restaurant gotten so much worse?

Unfortunately the response to these questions, "Because I said so," is not well received. There are no simple answers to these questions and there are many factors that may play a role in crafting a response, e.g., correct identification, knowledge of pest biology and habits, temperature, moisture, food resources, etc.

The answers to these questions typically can be found by looking at pest problems globally. In our industry there is a tendency to examine problems in a single dimensional plain, e.g., inspections focus at ground level, in the attic or in/on the wall. Unfortunately for us, pests don’t think — they just wander — and they bump into a wall and turn left or right, they hit a side wall and go up or down; in most cases there is neither rhyme nor reason to what they do. Thus, we don’t necessarily need to look outside the box until we have thoroughly checked inside the box.

MILLIPEDES/EARWIGS. "Why are the millipedes/earwigs so bad this year?" This question originates from the customer’s perspective, i.e., either they are seeing a lot of them crawling on the patio and up an exterior wall or they are getting into the house. In either case, the perception is that their numbers are greater. Possible explanations may include:

• The ground is saturated and they are trying to escape excessive moisture.

• Exterior areas are excessively dry and they are seeking moisture (critical for almost all arthropod survival).

• A mild winter failed to knock populations down.

• Importation in mulch or other organic material recently placed around the foundation.

• Change in product use that in the past kept populations in check.

PERIMETER PESTS. "Why are lady bugs, wasps and boxelder bugs in my house in mid-winter?" Research of the past several years has attempted to determine why these insects return to the same structures year after year. The reasons for them being inside are secondary to the attractiveness of a structure. Some things to consider:

• Research has shown that lady bugs tend to be attracted to white (or light-colored) houses in prominent locations, e.g., at the top of a hill.

• Boxelder bugs and similar insects feed on their respective host trees and plants and with the onset of fall normally overwinter in protected areas on the trees, e.g., under the bark. However, they find siding, gaps around doors and windows and other protected areas on structures suitable alternatives to natural protection.

• Lady bugs in the larval stage can be found actively feeding on other insects that attack trees and ornamentals, thus bringing them in close proximity to structures. Like boxelder bugs, they need to find protected areas to overwinter and seek out similar areas in structures.

• Failure to seal interior openings that allow these insects to enter the structure on a warm winter day.

• Failure to make a timely residual insecticide application in the fall of the year when these insects begin to congregate on the walls of structures (typically southern and western exposures).

GROUND BEETLES/SPRINGTAILS. "Why are ground beetles and springtails being found on upper floors?" Typically, these moisture-loving insects are found at ground level, occasionally gaining entry around doors and windows. When they begin to occur on the upper levels of buildings you need to begin looking up instead of at the ground. Here are some additional thoughts:

• Both insects can survive on the moisture and accumulation of organic matter in gutters and flat rooftops. When conditions begin to dry out these insects seek the protection of the building interior.

• Decaying window and door frames and other structural elements provide a suitable habitat for these insects to survive.

• Ivy and vines growing on the side of structures can extend up many floors, offering these insect pests access up the side of the structure, protection from the elements, moisture and food.

• Once springtails are established they frequently are found in bathrooms and kitchens where moisture is abundant.

As pest management professionals it is imperative that we respond to these questions in a knowledgeable manner, i.e., we do not just wing it. If you do not have a reasonable answer to the question, there is no shame in seeking assistance and getting back to the customer — it’s the professional thing to do. Furthermore, the answers to these questions lead us to possible solutions to the customer’s problem.

The author is technical director of American Pest Management, Takoma Park, Md. He can be reached at 301/891-2600 or via e-mail at rkramer@giemedia.com.