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Pest of the Month - Oriental Cockroach

Oriental Cockroach life stages, Nebraska Extension Acreage Insights December 2017.
The life stages of an Oriental cockroach showing its incomplete metamorphosis from egg to adult; Photo from Lancaster Co. Extension; University of Nebraska

A Water Bug is Still a Cockroach

In some polite circles, particularly in The South, you will hear about problems at home with “water bugs”. This is just the fancy way of saying that someone is dealing with cockroaches, in particular the species known as the Oriental cockroach.

While not the most common pest cockroach, Oriental roaches do often find their way into homes and become a nuisance. Their nickname comes from their preference for wet hiding places around your home. You may find this insect in your basement, laundry room, or bathrooms, anywhere where there is moisture that accumulates. Outdoors they commonly settle in mulch beds, wood piles, outdoor drains, or in thick ground cover patches (such as euonymus or ivy covers), again anywhere where that is damp.

Oriental cockroaches are approximately 1 inch long, are black to dark brown, and have a greasy sheen to them. Males have wings covering 3/4 of their body and the female has very short wings but neither can fly. They are also unable to climb smooth vertical surfaces so you may find them trapped in porcelain sinks or tubs.

Oriental roaches can be controlled with classic tried and true IPM methods. First, these roaches typically enter the home from outside by coming in under door/window jambs. Therefore, securing windows and doors, screening or caulking to close holes in the foundation or window frame will deter entry. Reducing moisture and fixing leaks will also lower the attractiveness of the home. Treatments of dust products like boric acid, silica dust, or diatomaceous earth can be applied to voids and other harborages such as cracks and crevices. You can also create a perimeter of defense by applying a liquid application of bifenthrin (Ortho Home Defense) one foot up the foundation and three feet out into the landscape. The best method for established indoor roach problems is to set out bait traps. Baits are targeted towards cockroaches only and effectively eliminate whole populations. Only use baits indoors as their efficacy outside is limited.

Oriental Cockroach bait station, Nebraska Extension Acreage Insights December 2017.
Combat cockroach bait is a common choice for many homeowners dealing with roach problems.
Image of Jonathan Larson
Jonathan Larson
Extension Educator - Entomology

Jonathan Larson is the Nebraska Extension entomologist for Douglas and Sarpy counties. His main focus is lawn and landscape pests but he also helps with bed bugs, roaches, and any other home invader that has six or more legs. Jonathan has his Bachelor of Science in Entomology from Purdue University, and his Ph.D. in Entomology from the University of Kentucky.

Contact Jonathan at:
Douglas/Sarpy County Extension
8015 W Center Rd.
Omaha, NE 68124-3175
(402) 444-7804