Mediterranean Seed Bugs we believe

Subject: Thousands of beetles!
Location: Southern California (Thousand Oaks)
April 17, 2015 3:17 pm
My property is covered with these tiny beetles running around – and I would like to know what they are. They vary in size from not much bigger than a flea, to about 1/4″ long. They run in sort of like “fits and spurts”, and if I gently pick one up with a tissue to bring it back outside (some are getting in the house) they leave a brownish/reddish spot on the tissue (looks like blood, but I’m pretty sure I’m not smooshing them so it is probably more of an excretion). A couple of larger ones appeared to have an “X” design on their backs. I would appreciate any help in identifying them! Sorry I can’t get a better picture.
Signature: Thanks, Eve-Marier

Seed Bug Nymph
Seed Bug Nymph

Hi Eve,
This is not a beetle, but a True Bug, but there is not enough detail in your image to provide a more specific identification.

Thank you for your reply.  Here is a picture of a larger one where the design on its back is visible.  Can you ID it?  Thanks so much!

Mediterranean Seed Bug, we believe
Mediterranean Seed Bug, we believe

That is a big help Eve-Marie,
We believe you are being troubled by Mediterranean Seed Bugs,
Xanthochilus saturnius, a species well represented on BugGuide where it states:  “native to Europe and the Mediterranean, adventive in NA (WA-CA) and now locally abundant … earliest NA record: CA 1994 can be very abundant in grass seed fields in so. OR.”  According to the Pacific Northwest Insect Management Handbook:  “The Mediterranean seed bug, Xanthochilus saturnius, is very small with even more distinctive markings of black-on-tan. Behind the head is the thorax with a jet black band followed by a band of stippled brown. The large triangle between the wings (scutellum) is also jet black. A light stripe outlines the scutellum, and the posterior edge of the leathery portion of the wing, forming a distinct X. There are also three other jet black blotch markings on the wings. Oregon reports “It can be very abundant in grass seed fields in southern Oregon, indicating that it does feed on grass seed.” For that reason, it continues to be “regulated in foreign trade”. Even though they do no damage to house, humans, or pets, these seed bugs become a huge annoyance and costly to exterminate when they migrate into households.”

1 thought on “Mediterranean Seed Bugs we believe”

  1. These bugs have completely infested my home. We live next to a grass field, and are sorronded by fruit trees. We have them every where can we do anything to reduce the amount. My mom is ill and on oxegen will they affect her.


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