Recently Introduced Cockroach

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

Cockroach

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).

Cockroach
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bugman

BugMan aka Daniel Marlos has been identifying bugs since 1999. WhatsThatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

87 thoughts on “Recently Introduced Cockroach”

  1. 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.

    Reply
  2. 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.

    Reply
  3. 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.

    Reply
    • House-Burn-Down-ing is reserved for Lice! Keep your house, just sprinkle Diatomaceous Earth (garden grade not pool filter stuff), and be prepared to not vacuum for a week or two. Really should only have to put it around the perimeters, right next to outside doors, and around any other gaps to the outside. Another site recommended sealing up every gap/crack to keep them outside. I’m going to be doing Bemeficial Nematodes for termites (that might be lurking; no damage), which might also kill these in egg/baby form while on or in ground.
      I’ve only found two of these little guys, hope my DE attack does the trick.. Fingers crossed.

      Reply
      • S/B “Beneficial” Nematodes.
        You buy em online, spray on dampened ground and they seek out termites and EAT THE BABIES!!
        There are different kinds that attack different pests. I don’t use poisons of any kind if I can help it. So these guys sound like just the ticket.

        Reply
  4. 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.

    Reply
  5. 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.

    Reply
  6. 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.

    Reply
  7. 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

    Reply
  8. 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

    Reply
  9. 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!

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  10. 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.

    Reply
    • 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.

      Reply
  11. 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!

    Reply
  12. 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!

    Reply
  13. 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!

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  14. 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?

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  15. 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.

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  16. 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.

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  17. 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!

    Reply
  18. 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.

    Reply
  19. 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.

    Reply
  20. 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!

    Reply
    • I’m going to try diatomaceous earth (garden grade not the one for pool filter)… fingers crossed that will do it. I read they aren’t after the food like the ginormous roaches we hear about, but it might not hurt to include some borax (boron?) in the equation. Need to find out what they like to eat, and mix the borax into that.

      Reply
  21. 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.

    Reply
  22. 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.

    Reply
  23. 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.

    Reply
  24. 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.

    Reply
  25. 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.

    Reply
  26. 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.

    Reply
  27. 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!

    Reply
    • 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.

      Reply
  28. 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.

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  29. 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.

    Reply
  30. 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.

    Reply
  31. 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.

    Reply
  32. 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.

    Reply
    • Dawn,
      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.

      Reply
  33. 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.

    Reply
    • Dawn,
      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.

      Reply
  34. 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.

    Reply
    • Hi Christina, I live on Wetlands Edge Rd and they are bombarding us via the garage facing the Wetlands. Have you had any success getting rid of them? I found 2 in my room today and am freaking out. Let me Let me know what worked for you.

      Reply
  35. 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

    Reply
  36. (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! 🙂

    Reply
  37. 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.

    Reply
  38. 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?

    Reply
  39. 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?

    Reply
  40. 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.

    Reply
  41. 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.

    Reply
  42. I live in American Canyon, California. Live across the street from the marshland and our house is infested with them. Every time we open the garage about 15-20 of them come scurrying through. Last night they worked their way into bedroom and bedroom bath. Anyone have any tips to deal with them?

    Reply
  43. We just moved toTerra Linda San Rafael into our completely remodeled house . I have been finding these roaches in the house in various places. I’m going to spray doorways and put out sticky traps. August 7, 2018

    Reply
  44. We removed an old fallen barn out of our yard in Sonoma, CA, and we have a MAJOR infestation in the yard. Started finding a bunch of them in the house about a month ago, a we did a flea/roach fogger – haven’t seen them inside in a couple weeks so it seemed to work, for now anyway.
    Does anyone know how to get rid of them, especially in the yard?

    Reply
  45. We removed an old fallen barn out of our yard in Sonoma, CA, and we have a MAJOR infestation in the yard. Started finding a bunch of them in the house about a month ago, a we did a flea/roach fogger – haven’t seen them inside in a couple weeks so it seemed to work, for now anyway.
    Does anyone know how to get rid of them, especially in the yard?

    Reply
  46. We live in San Rafael and have a decent size 1 acre property. A few years ago we put down a lot of wood chips on the back yard of our property to help weed control during spring and mud during winter.

    Ever since we put down the wood chips in the yard we have been absolutely under attack from these little cockroaches, it’s absolutely insane! I was able to pinpoint the wood chips as the source, or at least breeding ground, because the first year we put them down, if you brushed patch of wood chips aside with your foot you would see hundreds of them under the surface of the chips. I thought they would dissipate over the years, as the wood chips aged and degraded, but unfortunately it has continued.

    They show up in the summer, around June, and stay until about November. They are so small that they can get through very tiny cracks under doors, around window screens, attic vents, etc. No exaggeration, I kill 3-6 a day, every day IN THE HOUSE!

    Finally this year, I recently gave up hope that they would disappear as the wood chips aged and deteriorated. I think they have now become an everlasting presence on our property. My concern is that I don’t know how we will keep them out of the house. I’m 99% sure they are breeding/laying eggs/etc outside the house and only entering the house through cracks. So I don’t think any amount of fogging or fumigating of our house would do anything. If I find a solution I will report back after talking to some pest control companies.

    Reply
    • Egad. We just moved to Terra Linda after our 1953 Eichler , bought a year ago, was completely remodeled for accessibility, new sewer, plumbing, electrical, roof, walls moved , doorways widened. The roaches seem to have moved in before us. Ugh. I haven’t pursued how to eradicate them. Please keep us informed about your efforts to do so.
      Thank you.
      Laura Barnett

      Reply
  47. We live in San Rafael and have a decent size 1 acre property. A few years ago we put down a lot of wood chips on the back yard of our property to help weed control during spring and mud during winter.

    Ever since we put down the wood chips in the yard we have been absolutely under attack from these little cockroaches, it’s absolutely insane! I was able to pinpoint the wood chips as the source, or at least breeding ground, because the first year we put them down, if you brushed patch of wood chips aside with your foot you would see hundreds of them under the surface of the chips. I thought they would dissipate over the years, as the wood chips aged and degraded, but unfortunately it has continued.

    They show up in the summer, around June, and stay until about November. They are so small that they can get through very tiny cracks under doors, around window screens, attic vents, etc. No exaggeration, I kill 3-6 a day, every day IN THE HOUSE!

    Finally this year, I recently gave up hope that they would disappear as the wood chips aged and deteriorated. I think they have now become an everlasting presence on our property. My concern is that I don’t know how we will keep them out of the house. I’m 99% sure they are breeding/laying eggs/etc outside the house and only entering the house through cracks. So I don’t think any amount of fogging or fumigating of our house would do anything. If I find a solution I will report back after talking to some pest control companies.

    Reply
    • Egad. We just moved to Terra Linda after our 1953 Eichler , bought a year ago, was completely remodeled for accessibility, new sewer, plumbing, electrical, roof, walls moved , doorways widened. The roaches seem to have moved in before us. Ugh. I haven’t pursued how to eradicate them. Please keep us informed about your efforts to do so.
      Thank you.
      Laura Barnett

      Reply
  48. I live in Cloverdale. I had an invasion this summer in the front yard eating the leaves off a bunch off some type of volunteer trees that sprouted under my redwood tree. They totally ate all the leaves and left sticks. I thought they were some type of beetle. But now they have come in under the screen door into the living room. I have never seen any in the kitchen only the living room and the hall.
    Once I examined one I could tell it was some type of roach. It has been weeks of searching the Internet to finally confirm and identify them as roaches. I will be using diatomaceous earth in the yard and house to try and get rid of them.

    Reply
    • I’m in Petaluma and my cat is eating /killing them when they come in the house. Seems to be the best product I have found that works….I’ve only had a couple so far this summer tho.

      Reply
  49. I live in Cloverdale. I had an invasion this summer in the front yard eating the leaves off a bunch off some type of volunteer trees that sprouted under my redwood tree. They totally ate all the leaves and left sticks. I thought they were some type of beetle. But now they have come in under the screen door into the living room. I have never seen any in the kitchen only the living room and the hall.
    Once I examined one I could tell it was some type of roach. It has been weeks of searching the Internet to finally confirm and identify them as roaches. I will be using diatomaceous earth in the yard and house to try and get rid of them.

    Reply
  50. We have seen one or two of these in last couple of years in our house in Fremont. This week however, I already killed 4. They are very fast and unlike most roaches, run around during the daylight. I haven’t seen them outside but maybe I haven’t looked from the right spots. We also have wood chips on our yard like someone else here says, going to check under that.

    Reply
  51. Wood chips which provide habitat for these roaches are being used throughout the Bay Area and elsewhere. I think this is a fairly recent thing.

    Reply
  52. I live in Ukiah (one hr north of santa rosa. I have killed two of these bugs. One came running from flower bed that has rocks (instead of mulch). I believe it came out because I was spraying Ortho Home Defense Insect Killer. The spray did kill it but they are fast. The other one was on my front doorstep, I believe it was under my doormat, which it was running fast due to the spray as well. I have never seen them before, was freaking out thinking they were a cockroach since our local schools are infested with the Turkistan cockroaches.
    They have not been in my house or garage.
    Does anyone know what would kill them? I am thinking about just pouring the insect killer all over my yard that has dirt, rocks, flowers. I do have pets, dog and cat so using the Diatomaceous Earth is limited since it is harmful to pets.
    I was told to put the DE in our water meter box cause that is where cockroaches love to be, and I put it in my sprinkler system box too.
    Any feedback is greatly appreciated!

    Reply
  53. I live in Ukiah (one hr north of santa rosa. I have killed two of these bugs. One came running from flower bed that has rocks (instead of mulch). I believe it came out because I was spraying Ortho Home Defense Insect Killer. The spray did kill it but they are fast. The other one was on my front doorstep, I believe it was under my doormat, which it was running fast due to the spray as well. I have never seen them before, was freaking out thinking they were a cockroach since our local schools are infested with the Turkistan cockroaches.
    They have not been in my house or garage.
    Does anyone know what would kill them? I am thinking about just pouring the insect killer all over my yard that has dirt, rocks, flowers. I do have pets, dog and cat so using the Diatomaceous Earth is limited since it is harmful to pets.
    I was told to put the DE in our water meter box cause that is where cockroaches love to be, and I put it in my sprinkler system box too.
    Any feedback is greatly appreciated!

    Reply
  54. I live in Berkeley, and these are in my yard- in woodchips and rocks and are sometimes spotted in my house as well- some days we see more than others. We noticed them when we moved in to our new spot 2016. I am glad I found this spot! Thanks, all!

    Reply
    • Update. So these little suckers are everywhere outside in our Terralinda San Rafael property. My husbandry raked accumulated debris from around the house perimeter. I saw a gazillion disrupted sesame seed sized nymphs skittering across the concrete path to the soil. The roaches are definitely here to stay. They are expanding their habitat throughout the Bay Area and beyond.

      Reply
  55. Laura in Terralinda –, The first few years I noticed these little roaches, we had gazillions in the leaf litter. Now, the 4th year, we have gazillions of predaceous ground beetles (Carabidae) and wolf spiders, and I don’t see many cockroaches at all. So even if the roaches are here to stay, their predators will keep them from taking over. The only “pest control” I do is keep the garbage bins away from the house, keep debris from accumulating around the foundation, and thank the beetles and spiders. Oh, and check flower pots carefully before bringing them indoors.

    Reply
    • Thanks the roaches are everywhere now. They are here to stay. Gazillions in our garden. Nymphs that have recently hatched. I’m going to spay them with vinegar water solution. I’m cheering for the spiders and the beetles.

      Reply
  56. I had posted in 2015 I had found two in my house in Napa. We’ve moved to the country out in Vacaville and I just found one out back while playing in the sandbox. A lot of people out here use wood chips to help keep soil moist around bushes and trees and to keep weeds down. I did the latter and so I guess they are here now too!

    Reply
    • Since all the years of drought, the use of wood chips and bark is ubiquitous. Perfect environment for these critters. And so the invasion spreads.

      Reply

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