What's That Bug? does not endorse extermination

What bug is this?
Location:  Northern California, USA
September 5, 2010 1:41 am
We keep finding these bugs around our house. They are coming from the outside, they come in when we open the doors or windows. They are also all around the outside of the house and the walls outside of the house. Some are brown with a yellow stripe on its back. They move fast, so we thought they might be some kind of roach, but we are not sure what kind of bug it is.
Signature:  Carly


Hi Carly,
We did not recognize your Cockroach, which we had believed to be an immature nymph, but we located it on BugGuide, and it is a recently introduced species that has become established in California, and it is a wingless species,
Phyllodromica trivittata.  According to BugGuide it is:  “Recently introduced into California, apparently now in Marin, Petaluma and Cotati” and “Reports of high abundance both indoors and outdoors make it likely that reproduction is occurring outdoors with subsequent invasion of nearby structures. As this species adapts to this new environment, studies will need to be conducted to confirm this.”  BugGuide also reports:  “Known from dry habitats around the Mediterranean. It has been recorded from Morocco; Algeria; Spain; Italy (Sardinia Island); Italy (Sicily); Libya; and Israel. Given that it has not been recorded as being a pest in buildings in those countries (as far as I’m aware) it is unlikely to invade buildings in the USA. Comment by George Beccaloni (The Natural History Museum, London, UK).


What's That Bug? does not endorse extermination
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49 Responses to Recently Introduced Cockroach

  1. Chris says:

    I just wanted to report a sighting of the newly introduced Phyllodromica trivittata in Rohnert Park, CA which is just north or Petaluma. Sorry that we didn’t get a picture of it. My son spotted it when we were swimming in a pool. Like everybody else has confirmed, it is very rapid. It doesn’t seem too shy as it quickly crawled onto my finger when it had the chance. We left it where we found it and were excited to look for it on this website. Thanks again for all of the good information. You guys are awesome.

  2. Kimberly says:

    I live in Tempe, AZ and am battling an infestation of these. The last time I was in Petaluma, CA was over 4 years ago and I’ve never seen these until now.

  3. joe joe says:

    yeah these guys are up in Santa Rosa too.

  4. Adrienne Bryan says:

    Found TWO in same 12 hour period in Cloverdale, CA. waited until dark and scoured the house but found no more evidence so hoping they do colonize and sometimes ‘accidentally’ come inside…
    never really had experience with a pest inside of any sort so hoping its a fluke….
    going to try not to follow instinct to burn down my house.

  5. Jett says:

    I just discovered these one week ago. They are outside near the house. On the outside stairs. Inside the basement. And now I just found one on the window sill when I opened the window. They move FAST. So far I see them at dusk or at night.

    I live in the San Francisco Bay Area, specifically Port Costa, CA 94569. Contra Costa County, on the South side of the Carquinez Strait.

  6. Dave says:

    I have seen them in my backyard in Cloverdale, CA. They seem to live in leaf litter and are flushed out with a hose. There is more on this pdf. CALIFORNIA PLANT PEST & DISEASE REPORT
    Volume 25, Jan. 2008 – Dec. 2009

  7. Jett says:

    I just captured one in my upstairs bedroom. Will send it to the Contra Costa Department of Agriculture so they can confirm the species and document that it is now in Zip 94569.

    Informative BLOG post from July 2014, with helpful comments:

  8. Chez says:

    I live in Santa Rosa Ca. I have found hundreds and hundreds over the last couple months. Only a few have been spotted indoors. Anyone want to come collect them let me know, I found tons of them on a trail!

  9. Laurie says:

    Bodega Bay (Sonoma Co.) – We’ve had them for two years. The ground appears to be rolling with them when it’s warm, thus taking the fun out of yard work 🙁 Finding more of them in the house, at least a couple a day. Disappear over winter. I’ve also seen them in Tomales.

    • Dave says:

      Found my first one in the house. There seem to be less outside after making a concerted effort to clean up the leaf litter. I could be WAY wrong on that, I suppose.

    • yvonne weber says:

      we only started seeing them last year too…but our back yard in infested with them!!!

  10. Leah says:

    I am vacationing in Point Reyes, and the place I am renting is infested with them. It’s gross. I killed something like 15 of them today.

    They are over by the kitchen area, don’t seem to be in the bed area (thank GOD!). I just hope I don’t accidentally bring any home with myself when I leave. Revolting!

  11. yvonne weber says:

    I too am having a problem with these….I live in Santa Rosa and have a large field behind my house. All my kids toys are covered in them and I do find them in my house….EW!

  12. marina says:

    I too live in Santa Rosa and have found them inside as well as outside. With this many can an exterminator even get something like this under control?

  13. jewl says:

    Found one coming into the garage tonight and squished it. I hope these suckers are outside bugs! Anyone know what they eat?

  14. jewl says:

    Oh, and I’m at the north end of Rohnert Park near Petaluma Hill Road

  15. Jess says:

    We just encountered one of these little buggers in our upstairs hallway. In Youngstown Ohio. I have never seen one before, but this one was a female obviously, since it had an egg sac. I’m hoping they don’t become a problem.

    • bugman says:

      According to BugGuide, this recently introduced Mediterranean species is only reported from California. Have you had recent visitors from California, or perhaps Italy?

  16. Jess says:

    None that I’m aware of, but I just moved into this house, and don’t know what the people did before me. When I saw it on my beige carpet I freaked having never seen anything like it before. It almost blended in.

  17. stephanie says:

    We found one today, in our house in Forestville, CA. (west of Santa Rosa). I’m thankful for What’s That Bug and for people posting. We are taking the”friendly little cockroach” to our local Cooperative Extension office tomorrow. Will keep you posted. Thanks!

  18. David Brandt says:

    I work at Biella Elementary in Santa Rosa and I see them there at times-as well as my yard in Cloverdale. I emailed the Press Democrat about this but have heard nothing. I suppose it’s not newsworthy enough.

  19. Kiley k watts says:

    I’ve seen many in my backyard in Sonoma and they got my attention because they look like baby roaches. What really got me going was their presence in a heuchera plant. This heuchera was red and healthy till one day it was not. In a matter of a day or two, this plant looked sickly. I was going to cut away the dead leaves but realized it was a goner. I pulled it out of the ground and hundreds of these things ran away from the ground around the plant.

  20. Teri Ellicock says:

    I live in north Napa. I found one coming out from under the refrigerator four days ago and just found one in the cabinet next to the refrigerator. It fell out as I was pulling out a tray that was standing on end. So this means I now have roaches in my house? How can I get rid of them? Will borax work? Stressing!

  21. PBN says:

    Thanks for a great web site. These bugs have been around my house in north San Rafael (above China Camp State Park) for more than 8 years now. FYI, recently we got a cat… and they seem to be eating his kibble, but not his wet food.

  22. Juan de la Cruz says:

    They are now in Windsor, California.
    Regular sightings on my patio.

  23. Ben says:

    I am nearly certain that this is the variety that I am seeing now on all four sides of our home in Northern CA, Suisun City CA (Solano County). Fast runners, they’re in the mulch/bark in from yard and back, the garden, and in the lawns in front and back. I see them during day hours and night if I look without trying very hard. They are all fairly small, when compared to rouches I’ve seen in the past. They don’t appear to have wings and I haven’t seen any fly.

  24. David Brandt says:

    Luridiblatta trivittata. 3 lined cockroach. Keep the leaf litter down.

  25. Eric says:

    Thank you all for the info, we have found three over the past few days in Napa, Ca.
    #3 Spotted a night 9.50 pm ish
    Small bugger with strips.

  26. Ally says:

    Just found one in Pacifica, CA. Plenty of people travel to Sonoma, Petaluma, Napa, etc, so I’m wondering if a neighbor brought one home. We’ve had a recent neighbor come back from Portugal.

  27. Teresa says:

    This is the first year we are seeing an abundance of these roaches in our yard in southwest Petaluma. So far, they are only outdoors, on fallen fruit, in leaf litter, in close proximity with Argentine ants, and around the garbage cans. I’ve moved the garbage cans away from the house.

  28. Ruth Glenn says:

    We recently found these after visiting Monterey. We first foun one in our durty clothes from Monterey, one in our patio table and one in our garage. HOW DO WE GET RID OF THESE? I have small children and I can’t even imagine having these inside the house next!

    • Ben says:

      I have been seeing these around all sides outdoors of my mom’s house for a year or so. I see them primarily in the bark, mulch and if you were to move a rock that is used as a border in the yard there may be several. Over the course of 1-2 years, there has been just 2 found in the house. I did read somewhere that there isn’t any risk of them carrying diseases if that is any consolation, but I don’t have any link to provide you with. Pest control was considered to come out but in the end decided to forgo the pesticides as we all thought what is more harmful some bugs running around the yard and occasional one who slips into the home, or chemicals sprayed all around the home outside and maybe inside. It’s been months since we have seen any of these little bugs. There are often small children playing at the house too and chemicals although the pest control companies tell them they are kid and pet safe I take that with a grain of salt and accept the bugs.

    • Dave says:

      They tend to stay outside in the leaf litter. I spray the doorways and rarely see them inside.

  29. Dave says:

    We got rid of our lawn in N. Cal and they love the mulch around the plants. They are prolific this year. Pick up as much leaf litter as possible but that’s a pipe dream.

  30. Clarissa says:

    Windsor, California. Over the last few months I have seen these pests running around my home. The kitchen and bedroom are the most affected areas. Finally caught one. Ew.

  31. found three in the last two weeks in vallejo ca. first time i have seen them . one in medicine chest, one on kitchen counter , one on computer desk just now . i hope that’s all but for me when it rains it pours. keeping my fingers crossed.

  32. Ian says:

    I live in Napa CA. I Have found 3 in the last week inside my house, 1 in the bathroom, 1 in the living room, and 1 in the hall closet, I haven’t seen any outside or around the property. Does any one know the best and most effective way to get rid of them? I have a 4 year old son and definitely do not need to be subjecting him to harmful chemicals. Any advice is greatly appreciated.

  33. Dawn says:

    Have been seeing them
    For the past 3 years in Marshall, ca near point Reyes in west marin.
    More in the house this year, I believe they’re highjackers, coming in on shoes etc. seem outside at all hours and in the hay at our horse barn in petaluma/ cotati.
    Anyone had and success getting RID of them. Kitchen, bathroom and weirdly bedroom this fall.
    Not okay.
    We have our fair share of bug lord know and don’t need this one!
    Any advice welcome don’t like these guys.

    • David Brandt says:

      I doubt that this specie can get eliminated. I use a roach spray on all doorway thresholds as well as where the garage door comes down. I still see them at times in the house-but not to the point of being a pest. I get a lot of blue-belly fence lizards and they probably help to keep the numbers down. I rake up the leaf litter and they sure like the mulch in front. Chickens in your yard should help but this is here to stay.

  34. CHRISTINA HALL says:

    We live in American Canyon (right in between Vallejo and Napa). These little guys are increasing in numbers within our house (ewwww). We’ve never seen them until recently. When I say recently, I mean within the last 2 months. They are not too bothersome. However, I am concerned since, until now, I’ve never had to worry about anything being in my cereal box. Gross. Calling an extermination service a.s.a.p and doing a thorough cleaning, again.

  35. Sal says:

    Found 2 of these in the last two weeks in our home 1 during day light one at night it was extreme heat outside 109 at highest so I think they came in looking for.moisture. I’m in santa rosa ca

  36. Teresa says:

    (Updating my comment from Aug. 28, 2016) The summer of 2016 was the first year we saw these little gals in abundance in our yard in southwest Petaluma. This summer (2017) there have been very few. However, I am seeing an abundance of ground-running predaceous beetles (small carabids…not sure what species) and ground-running spiders (mainly small wolf spiders). I think these predators are helping us out, as we have never seen them this abundant before. So, to anyone who is freaking out about a sudden explosion of this new cockroach species, you might try the “do nothing” option, along with keeping your garbage cans and compost away from the house, picking up all fallen fruit, etc. It worked for me! 🙂

  37. Sheila Schwartz says:

    Found the first one on my boxspring when I was cleaning last week. Then under a pillow this week. Just found a third on the kitchen floor tonight. They are only the size of ladybugs. I hope I don’t find more, but I keep all food in ziplock bags, and no crumbs around so I’m not sure what to do. It doesn’t warrant spraying at this point, even if they could.

  38. Brian says:

    Just this week I’ve seen three of these in my kitchen near the sink at night. We live in Forestville, Ca
    Hadn’t seen cockroaches since my years in NYC and wasnt sure what they were but assumed they were roaches by the way they moved…creepy
    Also know where there’s one there are many more hiding. Doing home renovations might be why we’re seeing them emerge?

  39. Eve says:

    Just started seeing these over the past week in our house west of Sebastopol, in the kitchen, livingroom, and office. Maybe 2 or 3 a day. We keep things pretty clean around here, haven’t noticed them congregating around the cat dishes or anything like that. I suspect the woodpile, which I know has some funky wood.

  40. KayLee says:

    Just spotted one these little buggers last night in the kitchen! I freaked. Located in Gualala Ca, few miles off the coast! I’m hoping he just ventured in from outside. As we just remodeled this house.

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