Insight to Managing Cockroaches in a Multi-family Dwelling

Occasionally our Extension Office receives phone calls from apartment and condominium owners concerned about cockroach populations in their apartment and their apartment complex.  All it takes is one resident or one vendor to unknowingly introduce German or American cockroaches to a building. If the cockroaches are not identified and treated quickly, a problem typically emerges.  In multi-dwelling units such as apartments and condominiums, cockroach control often requires a team effort involving the residents, pest control company, property managers, and custodians.

The University of Florida/IFAS provides urban entomology research to help Floridians and pest control companies best control pest populations.   Below are tips and useful links from UF/IFAS scientists and extension agents to help solve cockroach infestations.

Exclusion

The first step in cockroach management is exclusion.  Do not allow the pest to enter the dwelling and become established.

Cockroaches enter buildings

• via cardboard boxes and paper bags from residents or vendors.
• through cracks along door and window frames.
• by commercial kitchens and vendors on boxes, cans, heating racks, and other supplies

Eliminate food, water, and harborage

• Do not keep cardboard boxes more than 3-6 months.  Eliminate cardboard as soon as possible.
• Practice sanitation (No food, liquids, or craft supplies left out, wipe down surfaces and sinks, etc.).

Seal around points of entry

• Seal around plumbing pipes.
• Check screens and seals around doors and windows.

Identification

Once a cockroach is found in an apartment, identify it as soon as possible.  Multiple cockroach species can establish in Florida homes due to humidity.  Different species may require differing treatments due to individual species’ lifecycle and behavior.  Send cockroach samples to the UF/IFAS Insect ID Lab.

Monitoring

Monitor for cockroaches by placing sticky traps along walls and edges, for example under a sink pressed up against the wall or back of a vanity.  This placement provides the best chance a cockroach will encounter a sticky trap.  If a cockroach is encountered during the monitoring process, the pest control company could collect them using a vacuum with a HEPA filter.

Mapping out the condominium/apartment complex and indicating which apartments reported complaints will help the pest control company target their control efforts.

Treatment

For recurring cockroach populations, baits are a recommended control as cockroaches can build up resistance quickly to insecticidal sprays.  Baits also provide a chance for secondary introduction as live roaches will eat the feces and the bodies of roaches that consumed the bait.  Cockroach baits should be placed in inconspicuous areas and away from pets, for example, under a sink or on the back of an outlet switch plate.

In multi-dwelling situations all players will need to be involved for the best long-term outcome.

More Information

For more detailed information, please visit Assessment-Based Pest Management of German Cockroaches which contains an IPM Decision Flow Chart useful for pest control companies and homeowners.  This document and a consultation with Dr. Faith Oi, UF/IFAS urban entomologist, were the sources for this blog post.

Ralph Mitchell, UF/IFAS Horticulture Agent in Charlotte County, wrote a blog post on managing cockroaches without insecticides.