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Green news from the UC Division of Agriculture and Natural Resources
by Gabriele A O'Neill
on August 1, 2013 at 4:03 PM
These bugs have been a regular occurence in Lake County and we've been aware of them for many years now, especially since we had somewhat of an "infestation" about three years ago, where a few could be found on every square foot of ground you looked at. During that year they did significant damage to our fruit (blackberries, soft figs, etc.)and could even be found inside heads of lettuce!  
I have seen them mistakenly referred to as boxelder bugs even on the IPM website, but didn't bother poiting it out, since, like you said, they are closely related and the management is the same.  
I found that the key to reducing their numbers is to kill the first ones that you notice emerging in early spring, as they are the mothers (or fathers...) of the thousands that follow otherwise.
by Bruce Hagen
on August 1, 2013 at 7:19 PM
They have been quite numerous in Somoma County for the last five years or so. They seem to be everywhere in ornamental landscaping. I haven't noticed any real damage.
by CRinCA
on September 2, 2013 at 4:08 PM
I disagree that these most likely don't cause harm. A large infestation in my garden has nearly whipped out my late harvest. The bugs are harvesting aphids, much like ants do, eating the honeydew the aphids produce. I have had to remove my cucumbers and squash because they were so covered with aphids and several stages of bordered plant bugs that the plants were dying. I will work hard this fall/winter/spring to get rid of them.
by Rebecca Miller-Cripps
on September 3, 2013 at 2:42 PM
Hi CRinCA,  
I wonder if you have squash bugs, not bordered plant bugs. The squash bug, Anasa tristis, is a common pest of all cucurbit crops, especially squash and pumpkins. They also have orange edging around their abdomens and they feed on cucurbit leaves. Young squash bugs look very aphid-like. Go to for more information.  
Rebecca miller-Cripps
by victor
on June 24, 2015 at 12:54 PM
I first noticed a few on my newly planted pineapple plant and I killed them. About a week later I noticed several more, after looking up, I realized I hadn't killed the parents for they were all of the same 'age' so to speak. I killed dozens and for a few days it was good. But they are back in large numbers again. I find about a dozen dead by my door, around eight by open windows, and even more in my young pineapple plant. I don't know where they are coming from.
by Jim Dowling
on July 4, 2015 at 10:42 AM
This is the second consequtive year these bordered plant bugs have been 'thick' around here. They're everywhere - all stages from larvae to adults. They decimated the tomato crop last year. This year I'm dusting the plants around the base with diatomaceous earth. So far, does seem to be helping.
by Janette
on July 31, 2015 at 7:52 AM
Found these first on my Lavender plant in June and they have since moved on to my cosmos. (Not in my veg garden yet.) This is the first time I have seen the nymphs, although the adults (pictured here) look familiar. There doesn't appear to be any damage to my plants so far; so I'm going to leave them alone this year and see what happens.
by Steve N. Ehrmann*
on January 26, 2016 at 9:16 PM
I have the Border Plant Bugs on my Nectaplum, and they effectively destroy most of this otherwise delicious fruit early on. I am wondering if tanglefoot on the trunk could keep them out of the canopy, but they seem to have wings (??). They are on peaches and raspberries as well, but don't seem to do as much damage. I also have the squash bugs on my Sweetmeat Squash. First a few adults are evident, and then thousands of the offspring ! Using a shop vacuum sounds like an effective method of capturing them when I am present. But by then it is probably too late !!
by Scott Oneto
on February 2, 2016 at 12:23 PM
I have heard of fruit injury being a problem with the bordered plant bug, however it does appear to be sporadic and usually is just a problem when large numbers exist. I am not sure if tangle foot would give much control since adults will often fly into the canopy to lay eggs.  
Lygus bugs, stink bugs, boxelder bugs and bordered plant bugs all use plant hosts in addition to fruit trees for feeding, reproduction, and overwintering. Most potential problems can be reduced by appropriately managing or removing the  
alternate hosts. These bugs feed primarily on broadleaf weeds in the orchard ground cover, on borders, or in nearby crop fields, especially alfalfa. To keep populations from building up in the orchard, it is best to plant a ground cover that will discourage encroaching weed hosts. Perennial grasses or other herbaceous cover crops that do not harbor plant bug pests are recommended. Proper ground cover management is especially critical in peach and nectarine orchards where cat-facing injury can be severe. Dry vegetation, mowing, herbicide treatment, and cultivation can all cause bugs in the ground cover to move into trees in search of alternate food. Avoid mowing, cultivation, and herbicide application during periods when bug  
populations are high and fruit is most susceptible to injury, such as during bloom, when fruit is young, and near fruit  
maturity. Remove weed hosts on orchard borders where possible and avoid planting alfalfa next to orchards.  
Such measures will help reduce the number of adults migrating into orchards during spring and summer. For orchards that suffer annual boxelder bug damage, removing host trees, such as female boxelder, maple, and ash, from the surrounding area can help reduce boxelder bug populations. However, this is often impractical for orchards that are adjacent to uncultivated areas with abundant boxelder stands, or near urban areas where host trees are in the landscape.
by Alan Lowry
on March 2, 2016 at 11:34 AM
Placerville Calif, I found that the bordered plant bugs showed up on the 29th of feb, 2016, I found about ten of them on my driveway. They seemed to cover a six foot square. The trees they seem to come from is a fruitless mulberry. they most be mom's and daddy's. should I worry about the tree's life.
by Scott Oneto
on March 7, 2016 at 9:41 AM
Hi Alan, you are right, these are probably adults and will likely reproduce soon. This time of the year it is very common to see these insects running around on the ground, especially concrete. These insects rarely cause significant damage to landscape trees, however if you want to try and keep numbers low, it is best to control them now. Removal is easy by knocking insects into a mason jar, vacuuming them up using a shop vac, or stepping on them. No chemical control is recommended.
by Nancy Myers
on April 12, 2016 at 4:13 AM
I live in Central Texas. We found a large number of infant Bordered Plant Bugs on our mailbox. The black bugs, with red dot on back, didn't seem to be feeding on our flowers so we left them alone. Should we spray to get rid of them?
by Scott Oneto
on April 18, 2016 at 3:18 PM
Hi Nancy, no need to spray. If you want you can knock them into a jar and dispose of them. Normally they cause minimal or minor damage to most plants. For specific questions you might want to try your local Texas Master Gardener program
by Steve
on May 25, 2016 at 2:56 PM
Have had them on my property in the Santa Cruz Mountains of California (sand hills type soil) for decades. Have seen the neon blue nymphs several times but never associated them with the ubiquitous adults until reading this. Funny thing is, contrary to others' comments, I only see them on the ground; never on the plants. I've seen absolutely no damage to plants, flowers, vegetables or fruit crops. Absolutely harmless here. And yes, they typically appear in Spring and are gone by mid-to-late summer.
by renata
on June 6, 2016 at 4:15 PM
I am fighting them by holding a bucket with water and shaking the clusters off of my plants the best i can and I just smash them with my fingers anywhere I see them. They are everywhere. Even though so far haven't notice major damage in plants, I can tell that it can get out of control really quick.
by Scott Oneto
on June 13, 2016 at 11:21 AM
Yes, shaking the insects into a bucket of soapy water is a great method! I also like the finger smashing technique. Thank you for sharing.
by Bonnie
on November 4, 2016 at 11:57 AM
I read somewhere that these can get into your house and destroy things made from cotton. Is this true? I am a seamstress, and I have a lot, and I mean A LOT, of cotton fabric. Thank you!
by Scott Oneto
on November 7, 2016 at 9:02 AM
Hi Bonnie, I am not aware of these insects causing any damage to cotton or other fabrics in the home. These insects have sucking mouth parts and feed on green plant tissues and fruits. They don't cause any chewing damage. They can occasionally be found in the home (along window sills, doors or other openings) but will usually die as there isn't sufficient food for them.
by Bug Expert
on April 20, 2017 at 12:04 PM
The bordered plant bugs don't usually cause problems with plants; however, they can be a nuisance. In most cases, there is no need for control of these bugs, since they don't cause significant harm to ornamental plants.
by Karen Holleran
on July 26, 2017 at 12:44 PM
I first saw these last season on my buckwheat plants, then more and more and they seem to like the milkweed too, and I'm wondering if they are eating the monarch larvae? I see eggs, then small caterpillars, then a week later, gone. could they be doing what the "milkweed bug" does too?  
I made the mistake of tolerating them, and now they seem to be ubiquitous in the yard, everywhere, just everywhere. Time to corral them little critters, as much as I hate to.
by Thyrell
on August 2, 2017 at 4:48 PM
I have these things so bad they are starying to infest my house! How can i get rid of the any ideas?
by Scott Oneto
on August 9, 2017 at 2:51 PM
They can be a nuisance when they get indoors. Although they often don't have a food source inside the home (as they feed on plants), they still can be a pest. Check for any holes in screens and make sure doors seal tight. You can remove these insects with a vacuum cleaner or hand pick into a jar. No chemical treatments are needed indoors.
by Nan Danford
on September 8, 2017 at 9:46 PM
These bugs are decimating our tomatoes and strawberries. They are sucking all od the jiuce out of them. I am relieved to hear that they are not laying eggs under the skin if the fruit. I wish I could post a picture.
by Scott Oneto
on September 15, 2017 at 4:44 PM
Many people have reported large populations this year. If they are on the fruit, one of the best methods I have found to remove them, it to walk through the garden with a tall jar. Just put the jar below the fruit and knock the insects off into the jar. Another option is to use a handheld, cordless vacuum.
by Sandy Fledderjohann
on June 25, 2018 at 1:31 PM
I'm a master gardener in El Paso County and for the last two summers, these bugs have destroyed my wild four-o-clocks which I love to see bloom. What do you suggest for spraying these villians? have tried flicking them into alcohol filled jars to no avail--eventually they scatter at my shadow and continue to multiply until the plant is sucked dry.
by Scott Oneto
on June 26, 2018 at 2:24 PM
Sandy, yes these insects can be a huge nuisance especially on flowering ornamentals. You can try some of the control strategies that we have outlined for the boxelder bug. Although a different insect, the control strategies are similar.
by Beth Bello
on June 29, 2018 at 9:36 PM
I did not realize the babies are the black shiny little beetles. They love strawberries. I have found luck with using diatomaceous earth. I sprinkle the plants when dry with it (do not breathe), and try to not get the diatomaceous earth wet for several days. They tend to disappear. It is suppose to slice up their bodies. I do know I have many adults right now fornicating, and may just do a hand pick on them. UGH
by j. robert dobbson
on July 24, 2018 at 9:12 PM
Watched some very early instar animals completely consume a lemon over a period of a few days.
by Janet Bair
on August 11, 2018 at 11:28 AM
Any chance of updating the Pest Notes for Boxelder Bug (which is also supposed to apply to Bordered Plant Bug)? Clearly there is a problem with these bugs, evidenced by numerous comments above. In western Sonoma County, I have thousands of them in my garden. They are destroying my strawberries, and any tomato that turns red. It is very difficult to hand pick them because they scatter rapidly when approached. It seems that soap sprays have limited effectiveness. I have not tried vacuumming yet and perhaps that is the next step.
by Mark Moody
on August 13, 2018 at 10:23 PM
I live in Washington State near the coast. I have a lot of these in my garden. They do no significant harm to my raspberries or blueberries. It is possible they might cause some damage to my strawberries but it is not significant unless they all seem to congregate on one berry. They seem to pay little attention to anything else. It is possible that they may be living off of small soil insects/creatures? I suck them off my strawberries with a handheld vacuum and feed them to the little cutthroat in the creek. They go bonkers for them and it is great fun watching the feeding frenzy.
by Deb Vadnais
on July 10, 2019 at 9:43 AM
Can anyone recommend other insects that will kill or eat them instead of spraying? Maybe nature can take its course?!
by Scott Oneto
on July 15, 2019 at 10:51 AM
Great question Deb! Yes, there are a number of insects that will feed on these pesky bugs. Many of them are generalist predators that feed on a variety of other insects. These include assassin bugs, ambush bugs, big-eyed bugs, damsel bugs, mantids, ground beetles and a variety of predatory wasps. One of the first steps is to learn to recognize these beneficial insects. Next it is important to provide habitat for these beneficial insects. Increasing the availability of flowers-especially native wildflowers is often the single most important strategy for increasing the abundance of beneficial insects. Like pollinators, such as bees, many insect predators feed on flower nectar or pollen during one or more of their life stages. A really great guide for identifying beneficial insects and a planting guide is listed below:
by Joni
on September 4, 2019 at 11:31 AM
I have had an infestation this year with these bugs going through 2 mating cycles, early spring and mid summer. They are definitely bordered bugs--black adults with orange borders, and nymphs are a shiny dark blue. They are everywhere--sucking my strawberries and blackberries dry, and they are all over my tomatoes, nectarines and feijoa--although not doing much damage there yet. Thinking about trying guinea hens for control (chickens do too much damage to the garden...)
by Scott Oneto
on September 10, 2019 at 5:03 PM
I would be interested in hearing about how it goes with the guinea hens if you decide to try them.
by Mary E. Mariani
on April 7, 2020 at 2:22 PM
Thanks for the several years of comments on managing this pest!
by Todd
on March 21, 2021 at 10:58 AM
I completely disagree with those who say they cause little to no damage. The have decimated my tomatoes and strawberries in the past year and they are problematic in my fruit trees. In all cases they gather on the fruit (usually in large groups) before it is ripe and in hours they can permanently damage the fruit where it will fall off or just shrivel up and never ripen. I have used the methods mention to remove them with out pesticides and the population continues to grow even though I go out on killing sprees, smashing them with every opportunity that I get. The time required to go out 2 or 3 times a day to mitigate this by hand in a small garden is not trivial.  
The only thing I have found that helps mitigate the damage is to keep the ground clear around the plants and trees and regularly check (daily) to clean off those that have gathered. I completely removed all the strawberries because this was just the perfect a breading ground for them. I would and have found thousands of nymphs gathered in the cover of the strawberries.  
Hosing down the plant daily just doesn't make sense like those mentioned, due to the issues this would cause. I might try diatomaceous earth this year again as deterrent, but in the past it had mixed reviews in my experience. I would really like to have those who think they are trivial come see the damage they can do and take this more seriously. I don't want to spray but would be extremely interested in an effective way to reduce their numbers.
by Scott Oneto
on May 3, 2021 at 4:12 PM
Todd, I wanted to thank you for your comments and appreciate your response. After co-authoring this article eight years ago, I have received numerous accounts like yours. I too have fallen victim of the large numbers of bordered plant bugs that can build up in my summer garden. I have found that scouting for adults early in the spring before the first generation of nymphs are produced does help tremendously. Once you get that first generation of bugs, it can be difficult to catch up using hand removal alone. I have found it somewhat helpful to eliminate hiding places such as piles of rocks, boards, leaves, and general debris close to the garden and structures. The adults hide during the day or overwinter in these sites. Rake leaves and remove weeds and grass from a 6- to 10-feet wide strip around the foundation, particularly on the south and west sides of the house. A weed and debris-free area tends to reduce the congregation of bugs near the foundation. However, I have also noticed that with more and more people using mulches like bark or wood chips for weed control, retaining soil moisture, or other benefits, this is also serving as a perfect environment for the adults.
by Donna LaRocca
on July 25, 2021 at 12:54 PM
I can see from all the past comments that I need to get these bugs under control now to avoid damage to my strawberries and tomatoes. I am gardening in 3 raised beds and so far they are only on the lone Alpine strawberry. I am in the Pacific NW, just next to Mt Rainer.
by Donna LaRocca
on July 25, 2021 at 12:58 PM
I can see from all the past comments that I need to get these bugs under control now to avoid damage to my strawberries and tomatoes. I am gardening in 3 raised beds and so far they are only on the lone Alpine strawberry. I am in the Pacific NW, just next to Mt Rainer.
by Norm
on September 26, 2023 at 5:07 PM
I have had and infestation of these bugs around my front yard 'fruitless' plum tree (which produces tons of useless small plums) for many years. I assume they feed on the plums that drop on the ground. Last year, I planted a thornless blackberry vine in the back yard and the nymphs have attacked the ripe fruit with a vengeance. Each berry was covered with 6-8 nymphs! I squash literally hundreds of these over the course of each spring and summer, both nymphs and adults, but they keep coming. Today I noticed they were attacking my lemon cucumber fruit. I would say they are a pestilence and out of control here in Northern California.
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