Ukiah High School Sees Sharp Decline in Cockroach Population

Today, the Ukiah High School campus has far fewer cockroaches than
it did a year ago.

Last year, in an effort to manage a Turkestan cockroach infestation, Ukiah Unified
School District (UUSD) began working with scientists from the California Department of
Pesticide Regulation as well as Dr. Andrew Sutherland from the University of California
Cooperative Extension.

Dr. Sutherland said, “When we started monitoring, we would find hundreds of
cockroaches in a single trap. Now we count cockroaches in the single digits. We’re dealing
with a small fraction of the original population.”

Dr. Sutherland credits UUSD’s success to its adoption of a preventive strategy
called Integrated Pest Management, or “IPM.” IPM uses ongoing pest management
activities to prevent pest populations from getting out of control, rather than responding
only when problems arise.

With Dr. Sutherland’s assistance, UUSD’s contracted pest exterminator and the
district’s maintenance and operations staff shifted their focus from spraying insecticides
around the perimeter of buildings on campus to “structural exclusion,” and they limited the
use of insecticides to baits and foams targeted specifically on cockroach population
centers. Structural exclusion includes activities like creating barriers between indoor and
outdoor spaces with door sweeps and sealing cracks in concrete sidewalks and walls to
reduce the places pests can hide and reproduce.

Dr. Sutherland then applied for grant funding from the National Pest Management
Association and the California Department of Pesticide Regulation to create demonstration
sites that included Ukiah High School and another public school in southern California.
This allowed him to devote more resources to studying the effects of this IPM approach
with the hope that it will provide a model for other school districts, institutions, and pest
control operators nationwide to safely and effectively manage outdoor nuisance cockroach
populations. For the study, Ukiah High School was divided into 24 treatment areas where
one of four bait treatments has been applied and evaluated since June 2017.

Dr. Sutherland highlighted the importance of reducing the pest populations while
limiting the use of insecticides. “We’ve had a lot of success with non-chemical tactics—
sealing buildings and concrete structures on campus. Now, we only apply insecticides in
problem areas,” he said. “And we can see it’s working.”