EPOW - Ecology Picture of the Week

Predator At The Window

Yellow Predaceous Stink Bug (Apateticus crocatus), Family Pentatomidae
Portland, Oregon

Explanation:  Run!  Hide the kids!  It's a ... a ... oh, only a Yellow Predaceous Stink Bug, clinging to a kitchen window.  

One of the larger specimens of insect order Hemiptera (the "true bugs"), this is a common native of North America.  

Yes, Yellow Predaceous Stink Bug is a predator.  And it does stink.  The larval stage of a related species of stink bug exudes a mix of chemical compounds from three abdominal glands on its dorsum (its back), the most volatile chemicals being tridecane and 2-octenal.  Interestingly, tridecane has a hydrocarbon odor, and according to the National Center for Biotechnology Information, "Repeated or prolonged skin contact may irritate or redden skin, progressing to dermatitis.  Exposure to high concentrations of vapor may result in headache and stupor."  

Wow, that doesn't sound like you want to be grabbing squishing, or otherwise disturbing these fine arthropods.  

But wait, the "predaceous" part of the name is something that we can live with.  These bugs are actually beneficial predators of caterpillars, especially tent caterpillars, and of other economically destructive insects.

So enjoy the predator at the window; it is part of the ecological system and of benefit to us!
  

Information:
   Percy, J., A. MacDonald, and J. Weatherston.  1980.  Ultrastructure of scent glands in larvae of Apateticus bracteatus (Hemiptera: Pentatomidae) and chemical composition of the secretion.  Canadian Journal of Zoology 58(11):2105-2115.