By Bill Willis (WAIT) and John McLamb (HSB)
November 29, 2016
It happens all the time, whether owners are present or not, night or day, in any neighborhood. Yes, the threat of a home or office invasion exists. People cringe at the thought of anything getting into their personal space uninvited with the intention of doing them harm or causing destruction.
Do any of these unsavory characters look familiar?
Depending on the species, newly hatched roaches can vary from 2mm-5mm in length. The immature young may shed (molt) up to thirteen times before becoming adults. As adult roaches, they can vary in size from about .25 inch to 2 inches. Knowing the different markings and sizes of the roach during each stage of its life can help in the identification.
All these guys are immigrants having arrived on cargo ships or in products from Tropical Africa, South America, Europe, and the Far East. Human activities continue to spread more of them around the world.
Most of the 70 species in America prefer staying outside as feral roaches in the woods “where the wild things are”, benefitting from the life cycles there. Roaches are not strict vegetarians, but will feast on a wide variety of organisms and materials. However, a few species, like those in the line-up above, quickly adapt to “human” home life and can become real pests.
Given unfavorable circumstances (cold, drought, predators), they’ll come for a visit. They’re not overly choosey and might be indicative of a failed “Good Housekeeping Seal of Approval” certificate. You could leave a light on, but it’s not necessary for them to find you, plus you’d probably scare them. Even the best of families could have a few in their closet. Roaches need what all creatures need for survival: shelter, food, and water plus a little love. Most human homes provide these ingredients.
A crack or crevice, duct, drain or sewer pipe is a possible path inside. Humans can carry them inside in bags or boxes, and other packages. Or they can come inside through open doors.
Roaches and flies have a reputation of being dirty and unsanitary. Both seek out and crawl through cracks, crevices, and unclean places. Roach’s dead skin (molt), feces, and saliva proteins can trigger or augment house allergies and asthma. With a life expectancy of one year, a lot of protein can accumulate and sensitize young children. Oriental cockroaches can be a source for many food-borne pathogens, including E.coli, Salmonella spp., and other pathogens.
Cockroaches have many natural predators, including man, toads, frogs, beetles, geckos and iguanas. Don’t put too much faith in the geckos and iguanas, for they are easily distracted and wander off. Humans on the other hand are highly excitable and could panic before causing too much harm.
Recent sightings have been reported in common spaces and offices. Fall and winter occurrences in laboratories, hallways, and break areas are common. Usually a single individual is observed when lights are first turned on, especially where food is present. Compost bins, recycling containers, and trash cans with discarded food items attract them.
According to John McLamb, our Integrated Pest Management Coordinator, our initial response would be a mechanical or physical approach. Cracks are sealed and door sweeps are replaced to help prevent the insects from entering the building. The widespread use of sprays or liquid insecticides is not generally sanctioned because of possible effects on research and the concern for allergic reactions. Bait stations and glue traps, placed in areas where the roaches may frequent, are possibilities.