https://hortnews.extension.iastate.edu/wood-cockroach

https://www.pubs.ext.vt.edu/content/pubs_ext_vt_edu/en/ENTO/ENTO-426/ENTO-426.html

https://extension.psu.edu/wood-cockroaches


Hi Lisa, (and Ann)
Thank you for your quick response.
The below quote from your response is what has me worried.
“They skitter .”
As soon as the direct sun is off our siding (about 5 to 6 pm) about 4 or 5 will begin to appear.  As I approach one it will immediately dart to find a gap in the clapboard. If it can’t find a place to hide (or I try to swat it) it will usually drop to the ground and be lost to me .
I have probably seen 50 or 60 in the last week, on siding, on screens, and in between the screen and window glass.  About 10 have made it into the house, found either high on a wall, three on the kitchen counter and one hiding under the  ill-fitting strainer in the bathroom sink.
The first cockroach was on the kitchen counter. I caught it and put it out the back door.  I noticed it hung around the door threshold all day. (It wasn’t injured.) That behavior made me wonder.
Inaturalist’s AI suggested it was either a tawny or dusky cockroach.  (Admittedly the picture wasn’t very good.)
In my opinion, they are definitely trying to get in the house and they definitely are very evasive when spotted.
Appearance-wise, they could be male wood cockroaches, but the behavior seems quite different than one would expect with wood cockroaches.
Linda

> On Jun 22, 2023, at 11:28 AM, Extension Foundation <ask> wrote:
> One simple distinction between cockroaches and wood roaches is that wood roaches move more slowly and don't skitter away to avoid humans.</ask>

Hello Linda,

I'm following up on your cockroach question. From the photo you shared, I agree that it looks like a dusky cockroach which is a type of wood roach -- here are some additional resources that might help with identification:

• https://bugguide.net/node/view/26906
• https://extension.umaine.edu/home-and-garden-ipm/fact-sheets/common-name-listing/cockroaches/
• https://extension.psu.edu/wood-cockroaches

If you'd like, you can send us a specimen and we will work with our Extension entomologist to make a positive ID. If you care to do that, please complete this form: https://www.uvm.edu/sites/default/files/Extension-Community-Horticulture/PDC_Specimen_Worksheet_fillable_form.pdf and send it to the lab (mailing address is included on the form).

In the meantime, if they are wood roaches (including dusky cockroach), you can try to reduce their breeding spots by removing any decayed and fallen logs close to the building and continue to physically remove them from your home. 

It is said that the males are particularly pesky around this time of year (May-June) as this is their mating season and so they tend to fly and travel in large numbers. Since they feed primarily on decaying organic material, again removing wood and leaf piles, and other areas where plant material accumulates and decays is a good idea.

Like other insects, they may be attracted by outdoor lights so it is suggested that residual insecticide sprays around doors, windows, porches, patios and other areas near outdoor lights will help control males.

I'm hoping this will be a short-lived problem for you! If you do choose to use an exterminator/pest control service, here is an excellent checklist for choosing a reputable business: http://www.npic.orst.edu/pest/selectpco.html.

Hello Linda,

We have no new news based on the additional photo you sent. Fortunately, wood roaches (which we still think they are based on the size) don't cause human harm and you could take a look at some of the resources we sent to try to exclude them from the house. We think that once the mating season has concluded, they will go away.