Red Shoulder Bugs: All You Need to Know in a Nutshell

Red Shoulder Bugs, also known as Golden Rain Tree Bugs, are fascinating insects that many people encounter in their gardens. These bugs belong to the family Rhopalidae and are often found in warmer climates. It’s essential to familiarize yourself with their characteristics, as they can sometimes be mistaken for other insects such as Boxelder Bugs or Jadera Bugs.

These bugs have a distinct appearance, with bright red nymphs that turn to dark gray or black as they mature. They are known for invading homes, seeking warm sheltered areas to overwinter. Apart from being a nuisance indoors, Red Shoulder Bugs can also feed on plants, which may impact the health and aesthetics of your garden. Knowing about their behavior and habits can help you manage an infestation or prevent them from becoming unwelcome guests in your home.

Identifying Red Shoulder Bugs

Red-shouldered bugs are a type of true bug in the insect family Jadera haematoloma. They can be found in the United States, especially in California and Texas, and also in parts of Mexico. These bugs are easy to identify with some key features.

  • Size: Adults are between 7.5 to 11 mm in length and 2.5 to 4.0 mm width.
  • Color: Red markings on the head, thorax, and wing pads, with black legs, antennae, and sometimes black on the head and thorax.
  • Red eyes: They have distinctive red eyes.

Nymphs, or immature red-shouldered bugs, are bright red with black legs and antennae. As they get older, parts of their body become dark gray to black.

Adult red-shouldered bugs have wings, unlike nymphs. Here’s an example for easier comparison:

Stage Wings Color Size (Length x Width) Additional features
Nymph No Bright red with black legs and antennae Smaller
Adult Yes Red markings and black 7.5 to 11 mm x 2.5 to 4.0 mm Red eyes, wings outlined in red

Keep an eye out for these distinct features to recognize red-shouldered bugs in your surroundings.

Life Cycle and Reproduction

Red Shoulder Bugs go through a fascinating life cycle. They start as eggs, typically laid on leaves.

  • Eggs: Females lay clusters of eggs on the undersides of leaves, offering some protection.
  • Leaves: These bugs favor plants like goldenrod and sunflowers, often found on their leaves.

Their life cycle consists of several stages, including hibernating as nymphs during winter months.

  • Hibernate: Nymphs of Red Shoulder Bugs overwinter, hiding in leaf litter or other protected areas.
  • Overwinter: This helps them survive cold temperatures and emerge in warmer weather to continue their life cycle.

As it gets warmer, nymphs develop wing pads, indicating their growth and progress towards adulthood.

  • Wing Pads: These small structures gradually develop as the nymphs grow and molt through their instar stages.

These bugs’ life cycle is highly influenced by the season, with adults becoming more active and reproductive in warmer months.

  • Season: Spring and summer are peak times for Red Shoulder Bugs to mate and lay eggs, completing their life cycle.

In summary, the Red Shoulder Bugs’ life cycle is an intriguing process that involves eggs, leaves, overwintering, hibernation, wing pad development, and seasonal influences. By understanding their life cycle and reproduction, we can better appreciate these unique insects.

Habitat and Diet

Red Shoulder Bugs, also known as Jadera bugs, are commonly found in various habitats near their preferred food sources. These bugs are attracted to certain trees and plants, including:

  • Ash
  • Boxelder
  • Goldenrain tree
  • Plum
  • Cherry
  • Chinaberry
  • Maple

Their primary diet consists of:

  • Sap
  • Flowers
  • Buds
  • Vegetation
  • Foliage

Here is a comparison of their preferred food sources:

Tree/Plant Part Consumed Importance to Red Shoulder Bugs
Boxelder Sap, flowers, buds Primary host
Goldenrain Flowers, buds Primary host
Maple Sap, flowers, buds Secondary host
Ash Sap, flowers, buds Secondary host
Plum Sap, flowers, buds Secondary host
Cherry Sap, flowers, buds Secondary host
Chinaberry Sap, flowers, buds Secondary host

The Red Shoulder Bugs also share a close relationship with the Soapberry bug. Their diets are similar as they both feed on plants, flowers, and foliage.

When in search of food, these insects are known to explore various plants and trees which is crucial for their survival.

Pros of this varied diet:

  • Adaptability in different habitats
  • Ability to find food sources in diverse environments

Cons:

  • Competition with other species for food sources
  • Dependence on specific host plants for optimal survival

In conclusion, understanding the habitat and diet of Red Shoulder Bugs is essential for managing and controlling their populations in various ecosystems.

Nuisance and Impact

Red Shoulder Bugs, also known as scentless plant bugs, can be a nuisance in yards and gardens. These pests are attracted to leaking tree sap, and can often be found congregating around lawns, crevices, and the trunk of trees.

  • Nuisance: They can invade outdoor spaces in large numbers, making it unpleasant for homeowners.
  • Impact: They do not cause significant damage to plants, but their presence can still be bothersome.

Examples of infestations include swarms on tree trunks or clustering near homes during overwintering season.

Comparison Table:

Feature Red Shoulder Bug Scentless Plant Bug
Color Reddish Brownish-salmon
Size 7.5 to 11 mm long 2.5 to 4.0 mm wide
Nuisance Yes Yes (if in large numbers)

To reduce their presence:

  • Seal cracks and crevices around your home.
  • Address leaking tree sap issues to reduce their food source.

Remember, when dealing with these bugs, it’s crucial to be patient and persistent to keep them at bay effectively.

Control and Removal

Keeping your home and surroundings clean is the first step to control Red Shoulder Bugs. Here are some methods to get rid of them:

  • Vacuuming: Use a vacuum cleaner along the edges, cracks, and corners of your home.
  • Soap and Water: A mixture of soap and water can be effective in removing these bugs from surfaces.
Method Pros Cons
Vacuuming Easy to use May miss some bugs
Soap & Water Inexpensive & eco-friendly Requires manual effort

When dealing with Red Shoulder Bugs, there are a few characteristics to consider:

  • Attracted to bright lights
  • Prefer warm environments

To keep these bugs away, try the following:

  • Seal cracks and gaps in your home
  • Dim outdoor lights during nighttime

By following these steps, you will have an effective strategy for controlling and removing Red Shoulder Bugs.

Suggested Readings

The Red-Shouldered Bug belongs to the order Hemiptera and the family Rhopalidae. They are commonly known as Jadera bugs or Golden Rain Tree bugs. Their scientific name is Jadera haematoloma.

Identification

  • Small size, around 1/2 inch long
  • Distinctive red and black coloration
  • Pronotum and thorax are black, while the abdomen is bright red

These bugs are often confused with Boxelder bugs, which are similar in appearance. Here’s a comparison table to help with identification:

Feature Red-Shouldered Bug Boxelder Bug
Scientific Name Jadera haematoloma Boisea trivittatus
Color Red and black Red and black
Size Around 1/2 inch long Around 1/2 inch long
Pronotum Black Black
Thorax Black Black
Abdomen Bright red Red markings

The Red-Shouldered Bug can be found in several habitats, such as goldenrain trees (Koelreuteria paniculata), apple, peach, and grape orchards. Additionally, they can be found in the Balloonvine and Sapindaceae family plants. For more information and help with identification, consider contacting your local extension office.

Reader Emails

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 – Scentless Plant Bug: Niesthrea louisianica

 

Spawn of Satan?
Okay, what am I dealing with here? With the bright colors, they look somehow evil. Please tell me that this isn’t an infestation of hellspawn. … BTW, those first photos were taken last night after I found the bugs, after 7 PM on an overcast day, so lighting conditions weren’t favorable. I’ve revisited them today and this is the best of the new photos I made. … South Carolina. More specifically, the peidmont reigon of South Carolina.
Darren

Hi Darren,
Thanks for getting back to us with a location. These are winged adult and immature Scentless Plant Bugs. The species Niesthrea louisianica does not have a 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” and the species has been “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%.” There is some good information on Dave’s Garden website.

Thanks! That also answered my unasked question as to what the plant was (its a Velvetleaf).

Letter 2 – Scentless Plant Bug: Niesthrea louisianica

 

Subject: Bug ID
Location: North Carolina (Durham)
September 28, 2012 6:41 pm
Help! These guys lay multiple deep red almost black eggs on budding flower bushes and seem to consume the flowers prior to them opening. Are they ruining my large flower bush? It is similar to a hibiscus. How can I control these? They seemed resistant to a natural pesticide or permethrin
Signature: Dr R

Scentless Plant Bug:  Niesthrea louisianica

Dear Dr R,
This is
Niesthrea louisianica, a Scentless Plant Bug without a common name.  They feed on the flowers and seeds of Hibiscus, Rose of Sharon and other members of the Mallow family, and to the best of our knowledge, they do not do any permanent damage to the plants.  We do not provide extermination advice.

Scentless Plant Bug

Letter 3 – Scentless Plant Bug: Niesthrea louisianica

 

Subject: What is this thing?
Location: Little Rock, AR
July 22, 2014 7:19 am
I found this in my back yard on a hollyhock while taking macro shots of bugs, and no one I know seems to know what it is. Legs of a cricket, body of a fly, wings of a wasp, head (and even mouth part) of any number of true bugs…we’re stumped.
Thanks so much! 🙂
Sincerely,
L.J.
Signature: L.J.

Scentless Plant Bug:  Niesthrea louisianica
Scentless Plant Bug: Niesthrea louisianica

Dear L.J.,
This is probably the finest image we have ever received of the Scentless Plant Bug,
Niesthrea louisianica, which does not have a 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.”

Daniel,
Thanks again!  We’re glad to have the mystery solved. 🙂
I have other bugs from all over my back yard I can’t identify, either, and some that I just can’t figure out the variety, if it’s okay to share them. Not because I want to show off the pictures, of course (though I certainly appreciate the compliment on the last one), but to see if y’all can tell me what they are.  I understand if you’re short on time, though. 🙂
Sincerely,
L.J.

Letter 4 – Scentless Plant Bugs: Niesthrea louisianica

 

Subject: please help identify
Location: north central Arkansas
September 29, 2013 12:07 pm
Just came home from church and these guys are all OVER my Rose of Sharon bush. There are hundreds, if not thousands of them. The smallest ones are solid red. The medium ones are spotted, and the largest ones have yellow wings. Can you help identify?
Signature: Kathy Phillips

Scentless Plant Bugs
Scentless Plant Bugs

Hi Kathy,
You have Scentless Plant Bugs,
Niesthrea louisianica, and it appears you have some winged adults as well as several immature instars.

Scentless Plant Bugs
Scentless Plant Bugs

Letter 5 – Scentless Plant Bugs

 

Subject: Bug ID
Location: Concord, NC 28025
September 22, 2015 10:09 am
We think these may be stink bugs, but we are unsure
Signature: Richard Schmidt

Scentless Plant Bugs
Scentless Plant Bugs

Dear Richard,
Though they are not Stink Bugs, these Scentless Plant Bugs in the family Rhopalidae are classified in the same order as Stink Bugs.  Your individuals are
Niesthrea louisianica, a species without a common name.  They are frequently found feeding on Rose of Sharon and related plants.  According to BugGuide, they are “an important biocontrol agent of velvetleaf (Abutilon theophrasti).”

Scentless Plant Bugs
Scentless Plant Bugs

Letter 6 – Scentless Plant Bugs on Rose of Sharon: Niesthrea louisianica

 

Subject:  Weird beetle?
Geographic location of the bug:  Northwest Georgia
Date: 09/29/2021
Time: 04:48 AM EDT
Your letter to the bugman:  I found these weird bugs all over my rose of Sharon tree in clusters on the buds that never opened. What are they?
How you want your letter signed:  Jms

Scentless Plant Bugs: Niesthrea louisianica

Dear Jms,
These are not Beetles.  They are Scentless Plant Bugs,
Niesthrea louisianica, and all of our reports are on Rose of Sharon.

Letter 7 – Scentless Plant Bug nymphs on Rose of Sharon

 

Need some assistance
We found these “nasties” on our Rose of Sharon in Hernando, Mississippi. We spent sometime looking on the Web for an Identification on them but cannot seem to find a good resource for identification. Can you please help? There seems to be two different species, or a young and adult in this photo. Thank you so much for your assistance and if you could direct me in how to remove them from my plant life as it is not helping the leaves and buds on the Rose of Sharon.
By the way we loved your site!
Sincerely
Bryan Howard

Hi Bryan,
You have Hemipterans, both the winged adult and nymph. These are True Bugs, related to Stink Bugs. Despite the conspicuous marking, we cannot find a good exact identification in any of our sources.

Update (05/29/2006)
We now know this is Niesthrea louisianica, a Scentless Plant Bug that is found on Rose of Sharon.

Letter 8 – Scentless Plant Bug Nymph

 

Subject: really bizarre bug found on hibiscus in PA
Location: Mercersburg, PA
August 28, 2012 10:32 pm
A friend posted the attached photo on Google+, and peaked my curiosity. I can’t track this insect down – know what it is?
Signature: BJ Denenberg

Scentless Plant Bug Nymph

Dear BJ,
This is a True Bug nymph in the suborder Heteroptera.  This photo is getting to be a little too far removed from its origin to make us comfortable.  Since you did not actually take the photo, we are assuming you have permission from your friend to submit it to our site.  If this insect was actually photographed on a hibiscus in Pennsylvania, then we suspect that it is an exotic import from some overseas nursery.  We do not believe this insect is native to North America.  It should be reported to local authorities.  If exotic Hemipterans become established in a new location, they can become especially troublesome.

Dear Daniel –
Thank you so much for that quick reply. Actually, I told my online friend that I would research the bug for her, but didn’t specifically get permission to submit the photo to you. I spent about an hour trying to identify it myself, and finally gave up and contacted you. I’m guessing she will be okay with it, but I will confirm. Please don’t re-post the photo until I am sure that she grants permission for that.
I will pass on your response to her immediately, and follow up with you. Thanks very much for getting back to me so quickly!
BJ

Hi BJ,
We already posted the photo.  If she wants it removed, let us know.  She can also provide a comment to the posting indicating firsthand observations.  We would really like to identify this Hemipteran which we suspect is an invasive exotic species.   Since it is immature, correct identification may be more difficult without a country of origin.

Eric Eaton Responds
Daniel:
That is the nymph of a rhopalid (family Rhopalidae), most likely Niesthrea louisianica.  Not recorded for Pennsylvania in Bugguide.net, however:
http://bugguide.net/node/view/227698/bgimage
Still, the range information suggests it should occur there.  Great image!
Eric

Thanks for correcting our error Eric.
Here is the species page from BugGuide.

Authors

    by
  • 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.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

6 thoughts on “Red Shoulder Bugs: All You Need to Know in a Nutshell”

  1. I have these scentless plant bugs on my rose of Sharon tree. do I need to do anything about them? if so, what? I live in fort worth, texas. thank you

    Reply
  2. I live inGrand Prairie Tx in Dallas county.. I have these insects on my peri annual hibiscus. Can you advise me on the best course of act to rid my yard of this critter

    Reply

Leave a Comment