Red-shouldered bugs can be a nuisance in and around your home, causing damage to plants and invading indoor spaces. In order to effectively eliminate these pests, it’s important to understand their behavior and lifecycle.
These bugs are dark gray with distinct red lines on the thorax, making them easily identifiable. They lay oval-shaped eggs, and their nymphs are bright red with black legs and antennae. As they grow older, the head, thorax, and legs darken to gray. Red-shouldered bugs can be mistaken for boxelder bugs, but there are key differences in appearance, such as the number of red lines on the thorax and wing markings.
Understanding Red-Shouldered Bugs
The red-shouldered bug (Jadera haematoloma) is a true bug belonging to the Hemiptera family. These insects are typically brownish-gray to black, with distinctive red eyes and red markings on their thorax. They are somewhat flattened in size, measuring between 3/8 to 5/8 inches long1.
Some key features of red-shouldered bugs include:
- Red eyes
- Red markings on thorax
- Flattened body shape
Habitat and Range
Red-shouldered bugs can be found in a wide range of locations across the United States, including states like California, Texas, and Florida2. Their habitat extends from the southern parts of the U.S. through Central America, Mexico, and even reaches as far south as Venezuela2.
Their preferred habitat includes:
- Landscaped areas
Life Cycle and Breeding
The life cycle of red-shouldered bugs is fairly straightforward. They undergo simple metamorphosis, which includes three stages: eggs, nymphs, and adults. The nymphs are bright red with black legs and antennae1. As they grow, the head, thorax, and other body parts become darker, eventually developing into adults.
A quick comparison of red-shouldered bugs and boxelder bugs, which they are often confused with:
|Feature||Red-Shouldered Bug||Boxelder Bug|
|Size||3/8 to 5/8 inches long3||0.5 inches long3|
|Color||Red eyes, red markings on thorax, brownish-gray body||Red eyes, red markings on thorax and wings, black body|
Red-Shouldered Bug Infestations
Signs of Infestation
Red-shouldered bugs are small insects, black in color with red markings on their bodies. They are members of the scentless plant bug group. Some signs of infestation include:
- Aggregations of red-shouldered bugs on vegetation, foliage, and buds
- Discoloration or curling leaves on host plants
Common Host Plants
Red-shouldered bugs feed on a variety of host plants. Some common host plants include:
- Western soapberry
- Soapberry plant family
- Goldenrain tree
These bugs can also sometimes be found on other plants like flowers or clover mites.
Impact on Gardens and Yards
While red-shouldered bugs can infest gardens and yards, they are considered mostly harmless pests. Their impact is minimal and includes:
- Feeding on developing seeds and foliage
- Slight damage to host plants, typically not severe or long-lasting
Here is a comparison table of red-shouldered bugs and other common garden pests:
|Pest||Impact on Gardens||Harmful to Pets||Host Plants|
|Red-shouldered bugs||Minimal impact, mostly harmless||No||Western soapberry, maple, soapberry family|
|Scentless plant bugs||Minimal to moderate impact||No||Various flowers, trees, and shrubs|
|Clover mites||Generally harmless||No||Lawns, flowers, and trees|
|Goldenrain tree bug||Moderate impact||No||Goldenrain tree|
In conclusion, red-shouldered bug infestations are typically not a significant concern for the health of your garden or yard. These pests can be an annoyance, but their impact on plants is generally minor.
Prevention and Control Methods
Sealing Entry Points
To prevent and control red-shouldered bugs, it’s essential to seal their entry points into your home. These pests can enter through:
- Cracks: Seal any cracks and gaps in your home’s foundation, walls, doors, and windows.
- Doors and windows: Ensure all doors and windows are properly sealed with weather-stripping.
Cultural Control Techniques
Cultural control techniques can significantly reduce red-shouldered bug populations. Some practical methods include:
- Removing boxelder trees: Boxelder trees are a primary food source for these pests. By removing these trees from your property, you can limit their food sources and discourage them from staying.
- Maintaining cleanliness: Keep your yard well-maintained, and sweep away any plant debris that might attract red-shouldered bugs.
Biological control can help decrease red-shouldered bug populations, as they have natural predators such as spiders. Encourage these natural predators’ presence by maintaining healthy, diverse gardens, and promoting a balanced ecosystem.
In extreme cases, you may need chemical control options. Some relevant methods include using:
- Insecticides: Employ a proven insecticide, following the product label instructions for safe use.
- Diatomaceous earth: Sprinkle diatomaceous earth around your property’s foundation and entry points, as this natural powder can help kill red-shouldered bugs.
Remember to consult with pest control companies for professional advice, whether it’s organic or chemical-based treatments.
|Sealing Entry Points||Cost-effective||Time-consuming|
|Cultural Control||Environmentally-friendly||May not be enough|
|Biological Control||Natural solution||Takes time|
|Chemical Control||Quick results||May harm beneficial insects|
It’s worth mentioning that implementing multiple control techniques will better protect your home from red-shouldered bugs. These methods can be used in combination to create a more formidable defense against these pests in various locations, such as Kansas, Arizona, North Carolina, Iowa, and Virginia.
Removal Techniques and Tools
Manually removing red-shouldered bugs is a straightforward method to control their population. It involves:
- Picking individual bugs by hand
- Dropping them into a bucket of soapy water
This option is best for those with smaller infestations or who want a chemical-free approach.
Vacuuming is a quick and simple way to collect large numbers of red-shouldered bugs:
- Use a vacuum cleaner with a hose attachment
- Target areas where bugs congregate around the home
This method is ideal for overwintering insects or those found indoors.
Traps can help contain red-shouldered bug populations by attracting and capturing them. Commonly used traps include:
- Sticky traps
- DIY traps with soapy water
Here’s a comparison of different removal methods:
|Manual||Chemical-free, low cost||Time-consuming, labor-intensive|
|Vacuuming||Fast, efficient||Requires a vacuum cleaner, limited outdoor use|
|Traps||Passive, continuous control||May not attract all bugs, needs regular maintenance|
Preventative measures to minimize red-shouldered bug infestations involve monitoring and controlling their breeding populations around trees such as cherry, plum, apple, chinaberry, or soapberry plant family in states like Alabama, Illinois, Missouri, Georgia, Pennsylvania, and Maryland. Proper pest control, including regular inspection of the surrounding landscape and sealing cracks and crevices in your home, can further minimize the risk of infestations.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Red Shouldered Pine Borer
Subject: Unidentified Beetle found in McCleary, WA
Location: McCleary, WA
August 20, 2012 10:04 pm
We are hoping you may be able to help us identify a beetle we found on our screen door this evening 8/20/2012, in McCleary, WA. It measured approximately 2cm. The antennae were alternating black and white (or at least black and a lighter, contrasting color). The texture of the shell/wings looked very ”pitted”.
Thank you for your help!
Signature: Sarah and Shawn Z
Dear Sarah and Shawn,
Your Longhorned Borer Beetle in the family Cerambycidae is Stictoleptura canadensis, and it goes by the common name Red Shouldered Pine Borer. It is a transcontinental species found in both the east and the west. We have an example of a Red Shouldered Pine Borer in our archives that is colored like your specimen, and we have another example of a Red Shouldered Pine Borer that is colored more like its common name indicates, with red shoulders. BugGuide shows both individuals with red elytra and others with black elytra and red shoulders and the only images of mating pairs of Red Shouldered Pine Borers on BugGuide have the female with the coloration like your individual and the male with red shoulders, however there is no indication on BugGuide that this is sexual dimorphism. To further complicate the picture, there are a few examples of all black Red Shouldered Pine Borers on BugGuide. We are going to contact Doug Yanega and Eric Eaton to see if either of them can explain this variation in coloration.
Doug Yanega explains the color variations
As noted in my field guide, S. canadensis (the eastern subspecies) varies from red-shouldered to completely red elytra, in both sexes. I didn’t investigate other subspecies, but can’t imagine why they wouldn’t also be variable in coloration. There are LOTS of cerambycids with numerous color variants (as opposed to sexual dimorphism), and they’re often sympatric (i.e., genuine variation, rather than geographic differentiation).
Dept. of Entomology
Entomology Research Museum
Univ. of California, Riverside, CA
Thank you so much!!! We thought we had correctly identified it as a female Elderberry Longhorn (Desmocerus auripennis) because it has the same texture on the outer wings and looked nearly identical. The only difference were the antennae, which were verigated (unlike the images of D.auripennis we found).
Would love to know what causes the color variation.
Again, thanks so much for getting back to us! We love your website!
-Sarah and Shawn Z
Letter 2 – Red Shouldered Pine Borer
Location: Castle Rock, CO
July 15, 2016 3:48 pm
My daughter found this bug on her neck while driving. She thinks it bit her and she does have a mark on her neck.
Can you tell me what it is?
Borer Beetles in the family Cerambycidae have very strong mandibles and the larger members in the family might even draw blood if they bite, but the bite is not considered to be dangerous. Though your daughter got a bite from this Red Shouldered Pine Borer, Stictoleptura canadensis, it sounds like it did not break the skin. The Red Shouldered Pine Borer is a highly variable species, and some individuals have very discreet shoulder patches while others have mostly red elytra. This BugGuide image is a good match for the markings on your individual.
Thank you so much for the speedy reply! She doesn’t have any marks on her neck today, so if it did bite it must have just started before she grabbed it.
Thanks again for all the information and references.
Letter 3 – Red Shouldered Bug Aggregation
Subject: colorful swarm
Location: Kissimmee, Florida
January 13, 2014 3:00 pm
I went walking in my neighborhood. These bugs covered one corner of a six foot fence and spread out more sparely farther down.
This aggregation of immature nymphs and winged adult Red Shouldered Bugs, Jadera haematoloma, is soaking up the winter sun. They are often found in association with goldenrain trees, and they are sometimes called Goldenrain Tree Bugs.
Letter 4 – Red Shouldered Bug
We have a lot of beetles in our Southern Calif. front yard for the second year in a row. I would really appreciate an ID so that I can figure out what they are doing here. Thanks so much.
This is not a beetle. It is a Scentless Plant Bug in the family Rhopalidae. More specifically, it is a Red Shouldered Bug, Jadera haematoloma. It is found in the Southern states, but BugGuide also lists it in the Southwest. This species is commonly associated with the Goldenrain Tree.
Letter 5 – Red Shouldered Bug
red/orange eyed bugs
Location: northcentral Texas
May 21, 2011 5:13 pm
These bugs/beetles were crawling around the sidewalk and rocks at Elm Fork Nature Preserve in Carrollton, Texas. I believe it was summer and they have been spotted in dry fallen leaves at Hagerman NWR in Sherman, Texas also.
Signature: Brenda Loveless
You encountered an aggregation of Red Shouldered Bugs, Jadera haematoloma, also known as Goldenrain Tree Bugs. The winged individual is an adult, and the individual with more red markings is an immature nymph. Red Shouldered Bugs often form large aggregations. You may read more about the Red Shouldered Bug on BugGuide.
Letter 6 – Red Shouldered Bug
general info on this bug
Location: central valley in Atwater, ca
April 29, 2012 2:04 pm
Can u please help on general info on this bug???? thank you…
Signature: I took this picture
Letter 7 – Red Shouldered Bug
Subject: Indianapolis Beetle
Location: Indianapolis, IN
March 29, 2014 7:08 pm
We saw this bug at a house we are considering buying. Should we be concerned about an infestation? Is it a type of cockroach?
Signature: Corey C.
This is a Red Shouldered Bug, Jadera haematoloma, and it is basically a benign species, however, when they have a food source and conditions are correct, they can become quite plentiful when they gather in aggregations, and then they might become a nuisance. Red Shouldered Bugs feed on the seeds of various plants, including the Goldenrain Tree, Koelreuteria sp. According to BugGuide: “Adults and larvae tend to feed in groups, and favor developing seeds and fruits of their favored hosts, but will also suck sap from foliage, flowers, buds, or oozing stems. They feed on a variety of plants primarily in and related to the family Sapindaceae. Favorites include Balloonvine (Cardiospermum species) and Goldenrain Tree (Koelreuteria sp.), both in Sapindaceae, and they regularly use Soapberry (Sapindus sp.; Sapindaceae) and Maple/Boxelder (Acer sp.; Aceraceae). Additionally, reported on a variety of other plants, especially feeding on fruit, including Chinaberry (Melia azedarach; Meliaceae), Fig (Ficus spp.; Moraceae), Althaea (Malvaceae), Plum, Cherry, & Peach (Prunus sp.; Rosaceae), Apple (Malus sp.; Rosaceae), Grape (Vitis sp.; Vitaceae), Ash (Fraxinus sp.; Oleaceae), etc. Adults sometimes gather around human food leftovers and other smashed insects to feed as well.” BugGuide also notes that the Red Shouldered Bug: “Also forms aggregations in winter to hibernate, often in association with human residences.”
Letter 8 – Red Shouldered Bug
Subject: What’s that bug?
Location: San Diego
September 18, 2016 5:49 pm
We found this insect in our house on the coast in San Diego California during the month of September. Based on the pictures on your site, it looks like the red shouldered pine borer or a blister beetle? We cannot tell. Please help!
Signature: sandy vissman
This is a Red Shouldered Bug, Jadera haematoloma, a species that frequently forms large aggregations around homes and gardens. Though it can be a nuisance when it appears in large numbers, it is considered a benign species.
Letter 9 – Red Shouldered Bug
Subject: Camarillo Ca bug
Location: Camarillo, CA
March 18, 2017 5:55 pm
My search only finds a Box Elder bug. Is this what this is?
They are all over my yard.
This is a Red Shouldered Bug, Jadera haematoloma, not a Boxelder Bug, though they are closely related. According to BugGuide, the habitat is: “Yards, gardens, riparian areas, and other areas in association with hostplants. Often found in large aggregations feeding on leaking tree sap, dead insects, or seeds that have fallen from trees overhead. Also forms aggregations in winter to hibernate, often in association with human residences.”
Letter 10 – Scentless Plant Bug
We found this critter on our rose of sharon in the fall
If you could identify them that would be great We live in High Point North carolina We were wondering if they were harmful to the plants or eating the aphids or if they are aphids
Letter 11 – Scentless Plant Bug
Two mystery bugs
September 21, 2009
Bug #1 – Brown, six legged with wings and looks to be a stinger. About 2 inches long. Found dead on our driveway.
Bug #2 – Brown and white spotted bugs with orange spots almost like a lady bug. Found on our althea red heart hibiscus buds.
Hi again Heather,
Bug #2 is a Scentless Plant Bug, Niesthrea louisianica, and it has no common name. According to BugGuide, it: “Feeds on flower buds and seeds of plants in the Mallow family (Malvaceae), such as Hibiscus and Rose of Sharon.” More importantly, BugGuide also indicates it is: “Used as a control of the invasive annual weed, Velvetleaf (Abutilon theophrasti). In one 1987 study mentioned here it was found to reduce seed production by 98%.” The brightly colored immature nymphs in your photo are wingless, but your photo also shows a winged adult, though the individual is not the point of focus in your photograph.
Letter 12 – Scentless Plant Bug
Unknown colorful “true bug”
June 8, 2010
These are some old photos I came across that were taken in July 2007 of unknown bugs feeding on seed pods of an unknown plant. I can’t find anything like them in your archives.
At the bottom
Dear At the bottom,
My you sure have a funny name. These are Scentless Plant Bugs in the family Rhopalidae. The species is Niesthrea louisianica, and the species has no common name. We have posted images in the past, most recently this letter in September 2009. According to BugGuide it: “Feeds on flower buds and seeds of plants in the Mallow family (Malvaceae), such as Hibiscus and Rose of Sharon.“
Thanks for the quick reply. I had looked at all the images in the category
“Aphids, Scale Insects, Leafhoppers, and Tree Hoppers”, which was the only one
that I noticed on the list on the left that I thought likely to contain them.
Letter 13 – Scentless Plant Bug from Cyprus
Subject: Black & Red Insect
February 4, 2017 10:54 am
I found this inside my house today. I live in Cyprus in the Mediterranean. Can you tell me what it is please & is it dangerous?
We quickly located your Scentless Plant Bug, Corizus hyoscyami, on FlickR, and we verified its identity on British Bugs where it states: “In addition to the distinctive markings, C. hyoscyami is further distinguished by its hairiness and the numerous veins in the apical wing membrane, characteristic of all Rhopalidae. Although historically confined to the coasts of southern Britain, this species is now found inland throughout England and Wales as far north as Yorkshire. It is associated with a range of plants, and overwinters as an adult, the new generation appearing in August-September. Nymphs are yellow/red-brown in colour and also rather hairy.”
Letter 14 – Scentless Plant Bug Nymph
Subject: Ladybug like insect
Geographic location of the bug: Northern Virginia
Time: 06:35 PM EDT
We can’t seem to find this bug anywhere, any help identifying it would be appreciated
How you want your letter signed: DBrown
Thanks for sending larger images. This is an immature Niesthrea louisianica, a Scentless Plant Bug in the family Rhopalidae with no common name. They are often found feeding on Rose of Sharon.
Thanks so much, several of us didn’t have any luck finding it online even tried google image search. Your book link takes me to Amazon, do you have your own store you sell them through?
Alas, What’s That Bug? is not selling Daniel’s book The Curious World of Bugs.