Last week, after spending three hours mowing the lawn, the heat prompted me to seek a water break. I collapsed into a shaded chair on the barn porch, ready to rest and rehydrate. That’s when I noticed something peculiar. The entire grass pasture before me seemed to be moving. Was I experiencing heatstroke? A mirage? Upon closer inspection, I realized the air just above the ground was swarming with hundreds, possibly thousands, of iridescent green beetles, commonly known as June bugs. Perhaps “May-through-July bugs” would be a more accurate name, given their mid-summer emergence.
Alt text: Detailed close-up of a vibrant green June bug beetle showcasing its iridescent shell and spiny legs, perched on a leaf.
As a child, I, along with other neighborhood kids, found great amusement in capturing these robust, inch-long beetles. We would carefully tie a piece of sewing thread around the insect’s body, allowing it to fly in circles, tethered to the string held in our small hands. (Do children still engage in this pastime today?) Once boredom set in, we would release the thread and let Mr. June Bug fly off freely. Everyone believed these beetles were harmless. But were they truly?
Green June bugs are not vectors of disease, nor do they bite. They pose no threat to humans or pets, although their spiny legs might feel like a slight pinch upon landing. They do not invade homes. However, June bugs are not entirely harmless. In terms of plant damage, they are only slightly less destructive than Japanese beetles. They are voracious herbivores, capable of causing significant damage to various crops. Their preferred foods include berries, tomatoes, grapes, peaches, plums, figs, and corn. When these succulent treats are unavailable, they readily consume grasses, oak leaves, and flowers.
Alt text: Illustrative depiction of green June beetle damage on corn crops, highlighting the extensive feeding marks on leaves and stalks.
Green June bugs (Cotinis nitida, prevalent throughout the southeastern United States) undergo complete metamorphosis. Their life cycle begins as eggs, laid in clusters of 10-30 in shallow soil. They then spend up to three years as grubs. Pupation occurs, and they emerge as adult beetles when soil temperatures reach 70 degrees Fahrenheit. While a few adults may survive the winter underground, most live for less than a year, perishing by the end of summer. Skunks and large birds, such as crows, prey on the grubs.
Dead adult June bugs are commonly found upside down. As they near death, their hemolymph (insect blood) ceases to flow to their legs, rendering them unable to support their weight, causing them to topple over. They are attracted to nighttime lights, with males showing a stronger attraction than females, and may inadvertently meet their end by flying into outdoor bonfires. Snakes, lizards, frogs, and birds serve as natural predators for adult June bugs.
If you perceive an increase in June bug populations compared to previous years, your observation is likely accurate. Warmer weather conditions favor their population growth. Should their damage become noticeable, consider implementing measures to reduce their numbers. Prioritize natural methods before resorting to insecticides.
June bugs exhibit repellency to the scents of essential oils such as lavender, mint, and rosemary. Milky Spore bacteria can be employed to combat the grubs effectively. It is also effective against Japanese beetle grubs. Milky Spore is readily available at many garden centers and some large retail stores. Application instructions are provided on the product container.
While Milky Spore is not a rapid solution, it offers long-lasting control and is harmless to humans and pets. Two widely available insecticides, Carbaryl and Trichlorfon, are labeled for June bug control. Always read and strictly adhere to label instructions. A preemptive systemic insecticide, such as Imidacloprid, can also be used. However, systemic insecticides should be a last resort and only applied to non-food plants due to studies suggesting their contribution to honeybee colony collapse.
Do yellow “bug light” bulbs truly work? June bugs, along with yellow Sodium Vapor parking lot lights, find them less appealing than white incandescent lights. LED bulbs are even less attractive to them, offering another compelling reason to switch to energy-saving bulbs.
Folklore suggests that June bugs are blind. This is a misconception. Their tendency to bump into objects while walking or flying is due to their natural clumsiness. If they happen to fly into your hair, their leg spines might become entangled, which can feel unsettling, even if you know they cannot bite. Carefully capture the insect and find a child for a game of June bug airplane. If no children are present, feel free to lasso one with sewing thread. Your secret is safe with me.
