Green June beetles are one of the South’s better-known insects, though they are more likely to be called “June bugs.” Some folks even use this as a nickname or term of endearment, “Let’s go June Bug.” This insect also plays a key role in a popular southern phrase describing prompt or decisive action, “He jumped on that like a duck on a June bug!” And if you ever used “grubworms” for fish bait, you were probably fishing with green June beetle larvae. Then there’s the ever popular and fondly remembered southern pastime of flying a June bug on a string. Tie the string around the middle leg to get the most even flight.
Green June beetles belong to a large family of beetles known as scarab beetles and there is a large subgroup of scarab beetles that are similar to June beetles in size and biology, known collectively as May beetles. May beetles are much more numerous than June beetles, but they are not nearly as well-known because May beetles fly at night and are dull brown in color, while June beetles fly during the day and have that pretty, green and bronze color. This is much like the difference in moths and butterflies, or owls and many day-active birds. There is no point in being colorful if you only go out at night.
Despite their relative popularity in southern culture, green June beetles are pests. The larvae, known as white grubs, can cause problems in lawns and commercial turfgrass by damaging the roots, and heavy infestations can cause large patches of turf to turn brown and die due to excessive root pruning. Interestingly, green June beetle larvae travel through the root zone with their legs pointing up. They may look upside down to us, but it’s right-side up to a June beetle grub. Soil with high organic matter content is especially attractive to female June beetles, and heavy, damaging infestations of white grubs sometimes occur in pastures that are heavily fertilized with poultry manure. Adult June beetles are often found feeding on ripe fruits, such as figs, pears and peaches, sometimes in alarmingly large numbers. Such attacks are heaviest on over-ripe or decaying fruit. Despite their name, June beetles are often most numerous in July, but adults usually begin emerging in June.
Control: Harvesting ripening fruit promptly and collecting and discarding over-ripe fruit is the best way to limit damage by adult June beetles. Insecticide treatments are sometimes needed to prevent or control white grub damage in turfgrasses, and infestations of white grubs can consist of multiple species of scarab beetles, including June beetle larvae as well as several species of May beetles. Treatments are most effective when grubs are small, and this is usually in mid-summer.
See page 6 of Extension Publication 2331, Control Insect Pests in and Around the Home Lawn,
or page 9 of Publication 1858, Insect Control in Commercial Turf,
for more information on white grub control.
Blake Layton, Extension Entomology Specialist, Mississippi State University Extension Service. The information given here is for educational purposes only. Always read and follow current label directions. Specific commercial products are mentioned as examples only and reference to specific products or trade names is made with the understanding that no discrimination is intended to other products that may also be suitable and appropriately labeled.
Mississippi State University is an equal opportunity institution.