Home boxelder bug Boxelder Bugs-Pictures, Facts, Dangers, Life, Food& Look Alikes

Boxelder Bugs-Pictures, Facts, Dangers, Life, Food& Look Alikes

Boxelder bugs are trouble to homeowners once they invade their homes. Read on to find out what they are, what they look like, whether they bite and if they are harmful, their life cycle, where they live, what they eat, what they are attracted to, and bugs that resemble them.

What is a Boxelder Bug?

Boxelder bugs are bugs that feed on seed-bearing boxelder trees and hence their name, boxelder bugs.  In North America, the boxelder bugs are put into two prominent types. The classification is based on what these bugs feed on; ash trees and maple.

Native to the western states, boxelder bugs are found from eastern Canada all the way to eastern United States; as well as the west to eastern Navada. Boxelder trees grow in the mentioned areas in big numbers.

Boxelder bugs are everywhere whether during spring or fall. In the United States, they are mostly seen in the early summer and spring.

During the cooler fall weather, the insects are found together on the south side of sidewalks, buildings and fences. They are also found on rock faces and tree trunks where they try to warm themselves.

They congregate around houses and you will need to be careful to identify them when they show up. To do this, you will need to know how boxelder bugs look like.

What they look like

In most cases, boxelder bugs are black in color. They have red lines along their body and on their wings as well. When boxelder bugs are at the nymph stage, they are red in color as soon as they hatch and they turn black as they age.

When they are young nymphs, boxelder bugs are 1.5millimetres long, that is, 0.6 inches. Adult boxelder bugs are up to 0.55 inches long. These bugs are described to have a body shape same as that of sunflower seeds.[1]

Box elder bugs are described as being flat and elongate. Both the eggs and the first segment of the bug’s leg are red. Looking at the anatomy of the boxelder bugs, you will notice that there are three red bands on the chest of these bugs. On the upper region of the bug’s wings, it has red bands which are diagonal.

The bugs have six legs and they also have two antennae. The antennae are half the length of their body.

To differentiate the nymphs from adult boxelder bugs, you can study their body shape closely. The body of the adult boxelder bug is flatter and oval in shape. Also, the nymphs do not have wings.


To clearly understand how the boxelder bugs look like, you should closely study the images below;

boxelder bug picture
swarm of Boxelder Bugs

Do Boxelder Bugs Bite?

Boxelder bugs do not actually bite but rather they pierce through the skin. This leaves the skin irritated and you may form a spot that is red in color resembling the one left by a mosquito bite. When the piercing is severe, you should seek medical attention.[2]

Are they Harmful/Dangerous

Some pets eat bugs and you should do everything to keep them from eating boxelder bugs. These bugs have a very bad taste (foul taste). If your dog eats the boxelder bugs, be sure it will vomit. Another possible reaction is that the dog may salivate excessively.

Cats on the other hand seem to enjoy eating the boxelder but they are still likely to be faced with the same reactions. Generally, boxelder bugs are not good for your pets and you should keep the pets as far as possible from these bugs.

Humans do not really need to worry about boxelder bugs except for the piercing and foul smell. Otherwise, boxelder bugs do not transmit diseases or cause and diseases.

Boxelder bugs cause a lot of discomfort once they infest your home, for that reason, you may want to keep them far from your home as much as possible.

Life Cycle & Span

Life Cycle

Boxelder bugs create homes on leaves of maple, ash, and box elder trees during warm seasons. The bugs prefer these locations since they offer a safe, well-nourished breeding home. The adult boxelder bugs lay their eggs on leaves or inside the host trees.

The eggs have an oval shape and they are red-brown or rust-red in color. This color of the eggs is convenient as it helps them blend with the tree color; keeping them safe from the predators.

Within a few days (approximately 10 to 14 days), the eggs hatch into nymphs which are bright red in color.[3] When it is summer time, these nymphs undergo molting eventually becoming adults. Once the bugs are fully mature, they start to reproduce.

Following the meteorological seasons, the life cycle of boxelder bugs would be described as follows;

Spring through summer

During spring, the weather begins to warm up and that is when the boxelder bugs emerge. The adult bugs eat plants and seeds on the ground. A couple of weeks following their first feeding, the boxelder bugs start mating.

From mid-July, the bugs move to the female boxelder trees which are seed bearing. They lay their eggs on branches, trunks and leaves. You will rarely find the box elder bugs on the male boxelder trees.

You cannot notice that the bugs are feeding on the trees since they cause no visible injury. In cases of high populations, you can easily spot nymphs feeding throughout summer in your garden.

Late summer and fall

During this time, boxelder bugs leave the trees to find safer areas for the winter. Adult boxelder bugs can fly as far as two miles.

During summer, eggs hatch and the young boxelder bugs eat maple leaves for full development. Nymphs may be present in the fall but only the fully grown adults get to survive winter. There only a single generation each year.

Winter and early spring

Boxelder bugs are inactive during winter. When the temperatures grow slightly warm, the boxelder bugs become mobile. It is during spring that the bugs leave the winter sites and fly to maple trees where they lay eggs for their next generation.[4]

Span-how long do boxelder bugs live?

Boxelder bugs have a very short lifespan. The period between birth and death of a boxelder is very short compared to the other types of bugs.

What do boxelder bugs eat?

Boxelder bugs feed on various types of plants. These plants include maple, ash, stonefruits (such as cherry, peach and plum), grass, grape, apple, and strawberry.

In most cases, however, these bugs are found on female boxelder trees where the nymphs and adults feed on developing seeds.

During spring and at the beginning of summer, adult boxelder bugs eat plants and seeds that are on the ground. Around mid -July, the bugs move to female boxelder trees which bear seeds. During summer, the bugs also feed on maple and ash trees.

What Attracts them?

Boxelder bugs are attracted to warm areas. They like buildings that have southern exposure or western exposure. A warm environment means more activity for the boxelder bugs. Boxelder bugs are found in groups on rocks, buildings and trees that are directly hit by the sun.

Boxelder bugs are so attracted to warmth that during the cold winter seasons, they hide in crevices and small cracks to insulate themselves.

Boxelder bug vs kissing bug

One of the bugs which commonly confused with boxelder bugs is the kissing bug. This bug, like boxelder bug is black and red in color.

Nevertheless, you can differentiate the two bugs by looking at the positioning of either the black or red coloration.  For instance, the boxelder bugs have the red marking on their wings.

Box elder bug eyes are red in color. These bugs do not also have bands around the margin of their abdomen. You can also differentiate the two bugs by looking at what they feed. As earlier mentioned, boxelder bugs feed on boxelder and maple trees.

Kissing bugs, as the name suggests, feed on blood. They bite human beings at night around the mouth and the eye region.  In most cases, these bugs will be found in people’s houses during the fall.

Other Bugs that look like boxelders

Most bugs which are easily confused with boxelder bugs are those bugs which are black with red stripes.

Below is a description of each of these bugs and a guideline on how to distinguish the boxelder bugs from them;

Small milkweed bug

These are bugs which hang around milkweed patch and feed on the seeds of the patch. These bugs have also been spotted to be feeding on flower nectar, preying on arthropods, and scavenging on insects that have died.

The largest the milkweed bugs can grow is 12mm. From a far, they look like boxelder bugs but they can be differentiated using the red orange ‘x’ shape on its back.

Bee assassin bug

This is a predator which eats any arthropod it comes across. The most common culprits are the honey bees.

This insect, like the boxelder bugs, has red markings on its body.

The markings of the assassin bug are however located along the abdomen sides. The bee assassin bugs vary in size ranging from 12mm to 20 mm.

Large milkweed bug

If you grow milkweed for monarchs, you must have come across these black red bugs. You might have seen them but confused them with boxelder bugs.

These bugs feed on nectar, occasionally, and in most cases, they feed on milkweed seeds. This is for both nymphs and adults. These bugs measure within a range of 10 mm to 18mm.

To distinguish these bugs from boxelder bugs, look closely at their front and back side of their bodies and you will see black diamonds appearing on a background that is red-orange.

Across the middle of the bug’s body, you will also notice a black band that is solid.

Milkweed assassin bug

Unlike most milkweed bugs, this bug does not prey on the milkweed plant. Milkweed assassin bugs are mostly interested in soft bodied insects; with a greater interest on caterpillars and beetles. The color match of black and red on its body makes it easy for you o confuse it for boxelder bugs.

However, if you look closely at this assassin bug, you will realize that the red color (sometimes appearing orange) is dominant with the markings on some parts of its body being black. The black markings are mainly on the wings and thorax.

Fire bug

This bug is not native to America but on few occasions, it has been spotted in the United States. It is also confused with boxelder bugs because of the red and black color.

The two can be distinguished because the fire bug has a black triangle with two easily noticeable spots at the back, on a red background.

Scarlet plant bug

This bug is red and black like the boxelder bug. The scarlet plant bugs belong to the plant bug family with most of the bugs in that family being names based on their host plants.

To differentiate these bugs from the boxelders, you will see that the scarlet plant bug has brilliant scarlet on the outer margins of its body and it is black at the center. These bugs are about 5mm to 7mm in length.

Two spotted stink bug

Like most of the bugs discussed above the stink bug is red and black in color. It can however be differentiated from the boxelder bug by the two black spots right behind the head. These bugs are beneficial predators and have a preference of feeding on Colorado potato beetles.

Cotton stainer bug

Compared to most bugs discussed above, the cotton stainer is considered the prettiest bug. Its red and black color makes it similar to the discussed bugs, especially the boxelder bugs.

However, the red and black colors all over the body of the cotton stainer bug are more pronounced and more appealing to the eye.

Further reading:

How to get rid of boxelder bugs for good


[1] https://www.domyown.com/box-elder-bug-identification-guide-a-717.html

[2] https://www.westernexterminator.com/occasional-invaders/boxelder-bug/

[3] https://utahpests.usu.edu/uppdl/files-ou/factsheet/Boxelder%20Bug.pdf

[4] https://extension.umn.edu/household-insects/boxelder-bugs


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