The sight of large numbers of insects clustering on sunny walls or near doorways often causes concern. The red-shouldered bug, Jadera haematoloma, is a common insect that tends to aggregate near homes. While their presence can be alarming, these bugs are generally categorized as nuisance pests rather than a genuine threat to human health or property. Understanding their nature and habits is key to addressing their occasional presence.
What Are Red-Shouldered Bugs?
The red-shouldered bug, also known as the golden rain tree bug or soapberry bug, belongs to the scientific order Hemiptera, which includes all “true bugs.” Adults are somewhat flattened, measuring approximately 3/8 to 5/8 inches long, with a brownish-gray to black body coloration. Their defining features are vibrant red eyes and distinctive red markings on the thorax, the segment directly behind the head, which gives them their common name.
Immature bugs, called nymphs, are even more brightly colored, appearing mostly red with developing black markings and wing pads. They are native to the United States and are found across various regions, often near their preferred food sources. They are frequently mistaken for the closely related boxelder bug, but the red-shouldered bug’s unique red patterning helps distinguish the species.
Assessing the True Threat
Red-shouldered bugs are considered medically harmless and pose no danger to humans or pets. They do not possess a stinger, are not known to bite defensively, and do not transmit diseases. This eliminates a primary concern people often have about aggregating insects.
Any damage they cause is typically minor and not structural; they do not chew wood, damage foundations, or infest food pantries. Their primary diet consists of seeds, mainly from trees in the soapberry family, such as the golden rain tree, boxelder, and chinaberry. While feeding on developing fruit from trees like plum or apple can occasionally cause minor dimpling or scarring, they are not significant agricultural pests.
The main issue is their tendency to become a nuisance when they gather in large numbers. In the fall, they seek warm, protected places to overwinter and may enter homes through small cracks and crevices. Once indoors, they can stain curtains or walls with fecal matter if crushed or left undisturbed, which is the extent of their damage to indoor spaces.
Managing Nuisance Infestations
Since red-shouldered bugs are a nuisance rather than a threat, management focuses on prevention and physical removal. The most effective approach is exclusion, which means sealing potential entry points into the structure before cooler weather arrives. Inspect and caulk all cracks and crevices around windows, door frames, utility openings, and the foundation to block their access.
For bugs that have already made their way indoors, simple physical removal is the safest method. When found congregating on walls or floors, they can be easily swept up or removed using a vacuum cleaner with an attachment. It is advisable to empty the vacuum canister outdoors immediately to prevent any lingering odor if the bugs are left inside the machine.
Outdoor control can involve removing or raking up the fallen seeds from host trees like golden rain trees. This eliminates their primary food source and reduces local populations. Chemical sprays are rarely necessary due to the bug’s harmless nature and are generally only warranted as a perimeter treatment on the exterior of a structure to prevent entry.