Western Corsair

unknown orange and black beetle
Location: northern california central valley
August 21, 2011 11:39 pm
Hi, I’ve come across 3 of these bugs in my establishment in the past two days. My son tried picking one up and it either stung or bit him with excruciating pain. These bugs can fly and only seem to appear in the evening.
Signature: bryan

Western Corsair

Hi Bryan,
This is an Assassin Bug known as a Western Corsair or Orange Spotted Assassin Bug,
Rasahus thoracicus.  Most Assassin Bugs are not aggressive, but they are predators and they are capable of biting humans with their mouths adapted for piercing and sucking fluids from prey.  According to BugGuide: “The western corsair feeds primarily on other insects and does not seek out warm-blooded animals or require a blood meal in order to reproduce. However, if it is picked up, it can inflict a bite that is quite painful.”

1 thought on “Western Corsair”

  1. We are new to the Sacramento area, but this is one bug we’ve encountered twice in three months. Both my wife and I were bitten on the back by one. I managed to catch the culprit after my wife was bitten. Although slightly squashed, I was able to identify it. I suspect it was on a patio chair when we both leaned against it. The chair is under a patio light. So, I guess I’ll move the chair. In the meantime, what’s the likelihood it carries Chagas disease?


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