If you’ve ever seen a June bug buzzing around a porch light at night, you may have noticed their erratic, clumsy flight patterns that often end with them crashing into windows or walls. So what causes these colorful beetles to fly so haphazardly?
Read on to learn all about the unique biology and behavior behind the June bug’s lack of flying finesse.
June Bugs Have Short Adult Life Spans
June bugs, also known as May beetles, have an extremely short adult lifespan. Here are some key facts about their brief time as mature insects:
June bugs as adults live only about 1-2 weeks
After spending most of their lives underground as grubs and larvae, june bugs finally morph into winged beetles during late spring and early summer. However, this adult form only lives for around 1-2 weeks. That’s an incredibly short amount of time compared to many other insects!
For example, some butterflies can live for up to a year as adults.
The june bug’s lifespan above ground is so brief that by the time you start noticing them banging against your screens in June, they may only have a few days left to live. Their short adult phase means every moment counts when it comes to reproducing and laying eggs for the next generation.
Their sole focus is mating, not skillful flying
The main goal of adult june bugs is mating and reproduction. As a result, they don’t invest energy in developing strong flight skills. June bugs are known for their clumsy, bumbling flight patterns. They bump into objects and have trouble controlling their direction because their sole focus is finding a mate, not navigating skillfully.
Male june bugs can spot females from up to 100 feet away! They immediately fly toward any scent of a female without paying attention to obstacles in their path. This single-minded pursuit of mates over navigating is why june bugs seem so uncoordinated in the air.
This short lifespan puts pressure on them to mate quickly
Knowing they only have days to live and reproduce, adult june bugs feel an urgency to find mates and breed as quickly as possible. The males fly around chaotically searching for females, while females emit pheromones to attract males from where they emerge.
There’s no time to waste on anything besides mating.
This rush leads to the clumsy, erratic flying and crashing into objects we observe in june bugs. They simply don’t have the luxury of carefully flying around or developing flying skills when their lifespan above ground is so painfully short.
The pressure is on to reproduce immediately, leading to the frantic, graceless mating behavior that defines june bugs.
They Have Large, Bulky Bodies
June bugs have heavy, rounded bodies
The body shape and size of June bugs (Phyllophaga spp.) contributes significantly to their reputation for clumsiness. As members of the beetle family Scarabaeidae, June bugs have very large and rounded hardened wing covers (called elytra) that meet in a straight line down the back, enclosing the hind wings.
This gives them a very heavy, broad appearance compared to many other flying insects. The elytra and abdomens of some species can measure over an inch long.
Their large size makes them aerodynamically clumsy
With their stocky figures and substantial mass, June beetles are often described by observers as bumbling and graceless in flight. Unlike slender, lightweight insects like dragonflies that can swiftly change direction midair, the bulkiness of June bugs hinders their aerial agility.
Their large size generates substantial air resistance, making controlled, nuanced movements more difficult.
University of California entomologists note that June beetle wings aren’t well-designed for stability, which also impacts their flight skills: “The ratio of body mass to wing area in June beetles results in a lack of agility and little ability to recover from unexpected shifts in direction or speed” (Source).
Maneuvering their big bodies in flight is challenging
June beetles’ ungainly flight patterns stem largely from the difficulties of directing their oversized bodies through the air with any precision. Initiating movement from a standstill requires rapidly beating their small wings to generate enough lift for their heavy mass.
Once airborne, simply remaining aloft can be an accomplishment.
Navigating a stable course is also tricky for the beetles. Any strong air current risks knocking the insects askew or sending them into an uncontrolled spiral. Strong winds frequently carry June beetles into buildings, trees, and other objects since regaining control mid-flight is so problematic.
Even slight breezes can foil their ability to travel in straight lines.
June beetles’ general clumsiness while airborne leads many observers to jokingly assume the insects are drunk or otherwise incompetent flyers. But in truth, the beetles are doing their best while burdened with bodies that pose inherent challenges for graceful flight.
Their Vision is Poor
June bugs have poor eyesight compared to other insects
June bugs, also known as May beetles or June beetles, have relatively poor vision compared to other insects like dragonflies and houseflies. While many insects have compound eyes with thousands of ommatidia (individual eye units), June beetles only have around 70 ommatidia in each eye.
This significantly limits their visual acuity and ability to detect fine details and fast movements. According to entomologists, June bugs have a visual resolution of about 0.5 degrees, compared to 5-10 degrees for dragonflies.
Their eyes are thus simpler and less adapted for hunting compared to predators.
In addition, June bugs have very limited ability to see colors. While bees can see ultraviolet and polarized light, June beetles only distinguish between light and dark. Their vision mainly relies on detecting movement and overall light levels rather than identifying objects or colors.
Their eyes are thus not well suited for avoiding obstacles or spotting food sources while in flight.
It’s hard for them to see obstacles and avoid collisions
Due to their poor eyesight, June bugs often have difficulty seeing objects in their path while flying. Windows, walls, trees, and other obstacles that are obvious to humans and many insects can be nearly invisible to June bugs until the last moment.
This frequently results in them crashing loudly into these barriers, bumping off, and continuing on their way seemingly unaffected.
While many insects rely heavily on vision for flight control and navigation, June bugs must largely rely on their other senses. Unfortunately, this makes it quite hard for them to swiftly adjust course or elevation to avoid collisions.
Their eyes allow them to see overall light/dark contrasts and some movement, but do not give them the visual acuity needed to deftly weave between objects.
Entomologists theorize that the June bugs do not really need highly complex or color-sensitive eyesight for their lifestyle and behaviors. Since they are not predators and do not seek out specific foods or mates visually, their vision tasks are simpler than other insects.
Their wing membranes contain sensory receptors that likely provide some information about air pressure and obstacles, but their eyes remain the primary sensors for flight.
They often crash into objects like windows and walls
June bugs’ poor vision leads them to frequently crash into objects such as windows and exterior walls as they bumble between food sources and mating areas. Attracted by exterior lights, they may swarm around houses only to loudly collide with the lighted windows and walls over and over as they fail to see the barriers.
This can be annoying for homeowners but is typically harmless to both the June bugs and property.
June bugs primarily fly at night, likely another evolutionary adaptation to their limited eyesight. The overall dim conditions provide good contrast for their vision while hiding the fine details of objects.
However, this can cause them to smack right into lighted windows and walls that suddenly appear bright to their eyes. Other nocturnal insects like moths exhibit similar behaviors for the same reasons.
During the day, June bugs may also fly into objects but generally at lower speeds. While their eyes work slightly better in natural daylight, they still struggle to identify specific forms and objects.
They primarily rely on their antennae to help locate plants, mates, and food sources by scent rather than sight. The occasional bump into a tree, wall, or human is inevitable given their blurred vision.
They Are Drawn to Light Sources
June bugs use light cues to orient themselves at night
June bugs, also known as May beetles, are nocturnal insects that rely on light cues to navigate and orient themselves at night. They use natural light from the moon and stars as guides for flight. However, artificial light sources can interfere with their normal light-oriented behavior.
After spending most of the day buried underground, adult June bugs emerge at dusk to feed and mate. Their compound eyes are highly sensitive to light, allowing them to see ultraviolet and polarized light – cues that help them stay on course.
Under natural conditions, June beetles fly towards any source of light they see, expecting it to be the moon or a star. This positive phototaxis allows them to maintain a straight flight path using celestial light as a guide.
Bright lights like porch lights confuse their navigation
Problems arise when June bugs encounter unnatural light sources like street lights or flood lights. These bright lights overwhelm their photoreceptors and distort their ability to see real moon or star light.
Unable to get their bearings, the disoriented June beetles end up frantically flying towards the artificial lights. They become “trapped” fluttering around light bulbs, repeatedly bumping into windows or walls near the light source.
Outdoor lights on houses, buildings, and lampposts all can disrupt the June bugs’ normal phototactic behaviors. Instead of navigating by quiet moonlight, they chaotically swarm and circle these much brighter lights.
Disoriented, they end up flying erratically around lights
June bugs are hardwired to fly towards light, but artificial lights totally confuse their natural orientation mechanisms. With their internal compasses disrupted, they lose control of straight, purposeful flight.
Erratic spiraling, looping, zigzagging, and bumping against light bulbs are common behaviors of disoriented June beetles. They become “trapped” by lights that interrupt their natural navigational abilities.
Colliding repeatedly into light bulbs leads to injuries, wing damage, and exhaustion in June beetles. Their legs and wing joints even can become permanently damaged from hours of struggling to escape the bright lights.
June bugs caught in artificial light traps often die from dehydration or predation by birds. The lights that attract and disorient them also make them more conspicuous targets for hungry predators.
How to Avoid June Bug Collisions
Turn off unnecessary outdoor lights at night
June bugs are attracted to light sources at night. By turning off any unnecessary outdoor lighting after dusk, you can help reduce the number of june bugs that fly near your home. Motion sensor lights are a great option since they only turn on when needed.
Using lower wattage bulbs can also help decrease the radius that lights will attract insects. The less light pollution, the fewer june bugs will collide into your windows and doors!
Use yellow bulbs that attract fewer insects
While june bugs are attracted to most light spectrums, research shows that yellow wavelengths tend to attract fewer nocturnal insects. Switching your outdoor lighting to yellow bulbs can cut down on june bug interest. Amber and orange bulbs have a similar effect.
LED bulbs that emit yellow wavelengths are an energy-efficient option. Although yellow bulbs will not completely deter june bugs, they can significantly reduce their numbers compared to standard white lighting.
Cover porch lights to direct light downwards
Installing covers over porch lights prevents the light from shining upwards and attracting flying insects from far away. Cylinder-shaped covers work well to direct light downwards instead of outwards. Covers are inexpensive, easy to install, and fit most outdoor light fixtures.
They can reduce june bug collisions by up to 90%! An added benefit is minimizing light pollution for neighbors and impact on nocturnal animals.
Install screens on windows and doors
Window and door screens provide a physical barrier to prevent june bugs from entering homes. Insect screening with 18×16 mesh size will effectively block june bugs while allowing air circulation. Make sure screens are properly installed and maintained without any gaps or holes.
Keep screens closed at night when june bugs are most active. For windows that are frequently opened, consider pull-down retractable screens. They make it easy to let in fresh air while keeping june bugs out!
Conclusion
In summary, June bugs appear clumsy and haphazard in flight due to their short adult lifespans, sizable bodies, poor eyesight, and attraction to artificial lights. While their erratic flight patterns may seem amusing at first, just remember these beetles are simply trying to make the most of their brief adulthood to find mates and reproduce.
So next time one careens into your porch light, have some sympathy for the clumsy June bug!
