Keep cockroaches under control

Published 1:48 pm Tuesday, June 2, 2009

Cockroaches are problems to homeowners, and they may transfer diseases or cause allergic reaction.

Some cockroaches live their entire lives inside homes or buildings, referred to as domestic cockroaches. The prime example is German cockroach.

Some cockroaches live both inside and outside, or move into homes only occasionally, referred to as peridomestic cockroaches. The main species are the American cockroach, oriental cockroaches, smokybrown cockroach, and the Asian cockroach (which only occurs in southern part of Alabama). They often move indoors when the weather outside becomes too cold, too hot, too wet, or too dry. Though they normally do not survive well inside, the American and oriental cockroaches can make a good living and successfully breed indoors if they can find an area with enough moisture and food.

If you are experiencing peridomestic cockroach problem inside homes, here are some tips for inspecting and managing them:

The best time to inspect is just after sunset when roaches become active

-Inspection should start with checking the building exterior. Roaches may hide in cracks and crevices on outside walls and foundations, under siding and openings around pipes, wire and cables where they enter buildings.

-Check landscaping and building surroundings: Since roaches like moist and shady areas, inspect around garbage cans and dumpster area. Check areas under trees and shrubs that have lots of leaf litter or mulch. Also, check rotting stumps or logs, wood piles and tree holes, compost or debris piles, planters and pots near the foundation of the building. Sewers are another place you should not miss, especially for the American cockroach that often lives and breeds in sewers.

-Check above, too. These cockroaches also can be found under roof overhangs and in roof gutters where they live and feed on collected leaves and debris.

The American cockroaches are the largest pest roaches and have the longest life cycle up to more than two years. They reproduce only in a certain season. Females deposit an egg case –– containing 13 to 18 eggs –– in April and May. Nymphs hatch in early June. This means American cockroach populations are at their highest in late summer and fall.

In the fall, the new crop of American cockroach nymphs often migrate, looking for food and overwintering sites. American cockroaches are the most common cockroach infesting sewers and storm drains. When the nymphs leave these sites, they often end up in buildings. The smokybrown cockroaches are also often found in sewers.

Consider this six-step program:

-When cockroaches are found on the exterior, treat the cracks and crevices where they are hiding with a residual insecticide. Use liquid insecticides or granular insecticides in infested sites around the foundation, windows, doors and other entry points.

-Make sure the harborage cracks and crevices are then caulked or sealed. Seal openings around windows, doors, vents, pipes and electrical conduits.

-Install door sweeps, thresholds and weather seals on doors, especially garage doors.

-Reduce outside lighting and/or use yellow bulbs instead.

-Move stacks of firewood, lumber, stones, etc., away from the foundation, clean gutters and avoid heavy mulching around the foundation. Debris piles can be treated with granular bait.

-Applying a regular perimeter barrier treatment can keep peridomestic cockroaches from moving into the building.

For more information, call 1-877-252-4769.

Nelson Wynn is a Shelby County extension agent. He can be reached by phone at 669–6763.