Subject: Is this an elm seed bug? Found in Southern CA
Location: N Los Angeles County, Southern California
December 14, 2014 5:26 pm
Hi! I’ve been trying so hard to identify this bug, which just appeared in my back yard this year, maybe early summertime. I’m in north Los Angeles County (town is Littlerock), Southern CA. They’ve gone from lumbering in sort-of lines along the ground to huddling in large numbers around bushes and under wood or metal, to now huddling en masse in the crevices of one of my large chinese elm trees. I took pictures; they are black and red, similar it looks like in shape etc. to your photos of the elm seed bug, but the markings on my bugs seem a bit different. I have various birds living out back (goose, emu, peahen, guinea hen, and occasionally chickens) and am wondering if these bugs are beneficial to my plants and/or birds, or if they are harmful. So far they’re not in the house, but I’m a little worried that might change! I’d appreciate any help you can give me on identifying these cute little huddlers — hopefully they are the good kind! ( I have several more pictures, by the way – your site only allowed me 3 so I tried to pick out the best 3)
Signature: Heidi Brooks

Mediterranean Red Bug

Mediterranean Red Bug

Dear Heidi,
These are Mediterranean Red Bugs,
Scantius aegyptius, a species that was introduced to Southern California several years ago in about 2009 and it finds our climate to its liking, so it is proliferating.  Here is what the UC Riverside Center for Invasive Species Research states:  “Damage: The literature contains very little information regarding the biology of S. aegyptius and Scantius species in general are not considered to be economically important species.  In California, Scantius has been observed feeding on the developing seeds and stems of Knotweed (Polygonum spp.) and Malva (Malva parviflora).  It is likely that S. aegyptius will feed on the seeds of several species of annual herbaceous plants.
The most noticeable impact of S. aegyptius in California will likely be the presence of large numbers of nymphs and adults migrating from drying annual weeds into adjacent developed areas.  These migrations consisting of thousands of individuals can be very conspicuous and lead to large aggregations on small patches of host plants causing concern to local residents who notice these obvious aggregations.”  Though they pose no immediate threat to crops, native plants or animals, the presence of a non-native species in large numbers can have significant effects on native species by displacing them in an ecosystem.

Aggregation of Mediterranean Red Bugs

Aggregation of Mediterranean Red Bugs

Hi Daniel,
Thank you so much for taking the time to respond!  I got your email this morning, plus responses on Facebook after I asked about these insects there as well.  I have a British friend who lives in Germany and encounters these red “fire bugs” often in his walks through the woods.  He sent me this link, where I learned more interesting info about them, and I’d like to pass it on to you.  It’s a German site translated into English (thanks, Google), and while parts of the translation are a bit amusing, I did learn more about these little huddle-bugs:
My friend also said that he notices wasps hang around the red bugs, so not sure if they are tasty to the wasps (or vice-versa).
Thanks again!
Heidi Brooks

Dear Heidi,
The link you provided is for a Firebug, a different species in the same family.  Again, your species is Scantius aegyptius and you can find more information on BugGuide.  When we first posted images of the Mediterranean Red Bug in 2010, we also incorrectly identified it as a very similar looking Firebug.

Wow!  I didn’t notice that – the markings are so specific, with a triangle and 2 dots, I thought they were the same bug.  I’ll have to do a little more research then, I think.  It’s been difficult to find much about these insects, but at least I know that they don’t seem harmful to my plants or people.  Thanks again — your responses mean a lot to me!

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Location: Littlerock, California

One Response to Mediterranean Red Bug Aggregation in Southern California

  1. Bob says:

    Just found a ton of them in our front yard for the first time. Just on the outskirts of Los Angeles.

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