Boxelder bugs are common insects found in many regions, often causing a nuisance when they gather in large numbers around homes and other structures.
They are typically associated with boxelder trees, but can also be found on ash and maple trees.
As these bugs are harmless to humans and pets, understanding their life cycle can help you manage their presence around your property.
The life cycle of boxelder bugs begins in the spring, when adults emerge from their overwintering sites and lay their eggs in crevices of boxelder bark, leaves, or other objects.
After about 11 to 14 days, these eggs hatch into wingless, red-abdomen nymphs, which then develop in stages throughout the summer before becoming adults.
You may see boxelder bugs at various stages of their development during the warmer months, with population spikes more likely during hot, dry seasons.
One crucial aspect to note is that boxelder bugs tend to congregate in large numbers on the south side of trees and buildings as the weather cools in the fall.
This behavior is an important factor to consider when planning control measures, such as sealing cracks and crevices or repairing window screens to prevent the adult bugs from entering your home.
Life Cycle of Boxelder Bugs
Eggs
Boxelder bugs start their life as eggs, which are typically laid on seed-bearing female boxelder trees during the summer months.
These eggs eventually hatch into nymphs, which is the next stage in their life cycle.
- Color: Yellowish-brown
- Size: Approximately 1 mm in length
- Duration: A few weeks before hatching
Nymphs
The hatched nymphs are smaller versions of adult boxelder bugs, with red and black markings.
These nymphs undergo several molting stages as they grow and develop throughout the summer.
- Color: Red and black
- Food: Sap from boxelder tree leaves and seeds
- Development: Progress through several stages before reaching adulthood
Adults
Adult boxelder bugs are easily recognizable by their distinctive black and red markings.
These bugs reach about ½ inch in length when fully grown. Adults are capable of reproduction, laying eggs to begin the next generation.
- Size: Approximately ½ inch in length
- Appearance: Oval, black with red or orange markings on wings and body
- Reproduction: Adults reproduce in the summer, laying eggs on boxelder trees
Comparison of Boxelder Bug Life Cycle Stages:
| Stage | Appearance | Size | Diet |
|---|---|---|---|
| Egg | Yellowish-brown | ~1 mm | N/A |
| Nymph | Red and black | Smaller | Sap from boxelder leaves and seeds |
| Adult | Oval, black with red markings | ~½ inch | Sap from boxelder leaves and seeds |
Lifespan
Boxelder bugs have a relatively short lifespan.
After hatching from eggs in the spring, they undergo several nymphal stages throughout the summer, maturing into adults by late summer or early fall.
As adults, they seek out overwintering sites to survive the colder months. While many of these bugs perish during winter due to environmental factors, some survive to emerge the following spring and start the cycle anew.
On average, a boxelder bug’s lifespan ranges from a few months to a year, with most of their life spent in the adult stage.
Habitat and Host Trees
Boxelder Trees
Boxelder bugs (Boisea trivittata) primarily feed on boxelder trees (Acer negundo).
Female boxelder trees produce seeds that serve as a main food source for these insects.
In North America, boxelder trees can often be found near rivers and streams.
- Common in North America
- Found near rivers and streams
- Female trees produce seeds
Ash Trees
Although their main host is the boxelder tree, boxelder bugs can also be found on ash trees (Fraxinus spp.) in some heavily infested areas.
Ash trees can serve as an alternative food source for boxelder bugs, providing sap from their leaves.
Maple Trees
Boxelder bugs are not only found on boxelder and ash trees, but also on maple trees (Acer spp.).
These insects feed on the sap of maple trees and can target both seed-bearing and non-seed-bearing trees, making them a more versatile host option for the bugs.
Comparison table:
| Tree Type | Main Host | Seed-Bearing Trees | Alternative Hosts |
|---|---|---|---|
| Boxelder | Yes | Female trees | N/A |
| Ash | No | N/A | Heavily infested areas |
| Maple | No | Both types | Versatile host option |
By understanding the preferred host trees of boxelder bugs, we can better comprehend their habitat and the factors that contribute to their population growth.
Seasonal Behavior
Spring
In spring, boxelder bugs emerge from their overwintering sites and start to feed on leaves and twigs of boxelder trees.
The adults lay eggs on leaves or bark, which hatch after about two weeks. Nymphs feed on newly formed plant tissues.
Fall
During fall, large populations of boxelder bugs congregate on the south side of trees and buildings to find warmth.
As temperatures drop, they begin to seek shelter inside homes, becoming a nuisance pest. They enter through cracks or crevices, damaged window screens, or insulation gaps.
Common entry points:
- Cracks and crevices
- Damaged window screens
- Insulation gaps
Winter
Boxelder bugs spend the winter months in hibernation within homes or other protected areas.
Most of the overwintering adults die off in cold weather without needing any chemical intervention. Proper home sealing can prevent entry and reduce infestations in the following season.
Physical Characteristics
Coloration
Boxelder bugs have a combination of red and black colors. Their distinct color pattern includes:
- Dark gray to black body
- Three red stripes on the thorax
- Red outlines on leathery parts of wings
- Red eyes
These red markings make it easy to identify boxelder bugs.
Wings
Boxelder bugs have two wings which are categorized into:
- Leathery wings
- Membranous wings
| Wing Type | Appearance |
|---|---|
| Leathery | Dark gray with red outlines |
| Membranous | Transparent |
The leathery wings are outlined in red, while the membranous wings allow for easy mobility.
Boxelder Bug Interactions
Nuisance Pest
Boxelder bugs are considered a nuisance pest due to their tendency to congregate around homes and buildings near boxelder trees, ash, and maple plants.
They may enter homes through small openings around windows and doors to seek warmth during the colder months.
Although these insects are not known to bite or cause diseases, some characteristics that contribute to their nuisance status include:
- Large numbers congregating on the south side of trees and buildings
- Release of a bad odor when crushed
- Occasional staining of surfaces due to their excrement
Predators
Boxelder bugs have natural predators, which help keep their populations in check. Some of the predators include:
- Spiders
- Praying mantises
- Assassin bugs
- Birds
These predators consume boxelder bugs, preventing them from becoming an overwhelming problem in many areas.
Relationship with Humans
Despite being a nuisance pest, boxelder bugs are harmless to humans and animals.
They do not transmit diseases or bite, and their main interaction with humans is the annoyance caused by their presence in large numbers around homes and buildings.
Handling boxelder bugs is also safe, but it is important to remember that they release an unpleasant odor when crushed.
Conclusion
Boxelder bugs, commonly associated with boxelder, ash, and maple trees, undergo a life cycle starting with eggs laid in spring and developing into nymphs and adults by summer’s end.
As temperatures drop, they seek warmth, often congregating on building exteriors. While harmless to humans, their large numbers can be bothersome.
Understanding their life cycle, preferred habitats, and seasonal behaviors can aid in effective management and prevention strategies.
5 Comments. Leave new
It’s Bugstock!!
Do these bugs get as far west as Canadian Rockies, it appears I have them on my home in Cranbrook, BC. Is this possible?
There is also a Western Boxelder Bug that is found west of the Rockies, according to BugGuide.
How do you get rid of the bugs How do you get rid of box bug’s
We do not offer extermination advice.