May Beetles are also called June bugs because they are particularly active during summer, usually around the porch light. This beetle is not the big green June bug – but we’ll be seeing them later on, too. There are many species in the Phyllophaga genus and they look like each other in many ways, though some are darker than others. The May-June beetle has a sturdy, oblong, brown body with shiny wing covers (elytra) protecting their wings. With jointed brown legs they can get a powerful grip on window screens and door frames.
They are not dangerous to people, but they used to be agricultural pests in orchards, groves, sod farms, and crops and as part of the white grub pest pool, their larvae can be a nuisance.
White grubs are the larvae of scarab beetles, an insect family with about 30,000 different member species in a number of subfamilies and tribes. All these grubs have cream-colored bodies with yellow to brownish heads, brownish hind parts, and six legs. Mature grubs vary in length from 1⁄4 to 1 1⁄2 inches, depending on the species. White grubs usually lie in a curled or C-shaped position. The May-June beetle larvae feed on roots and decaying vegetation in the soil, while the adults feed on leave of various plants.
Just as the adult beetles are not all the same, control of their larvae takes a different approach too. Milky spore is a biological treatment method, but it only works on the Japanese beetle grub. The goal of pest management is integrated pest management (IPM), to keep damage to an acceptable level while using monitoring and appropriate control tactics. It’s an approach that uses knowledge about pests and their life cycles, cultural practices, nonchemical methods, and pesticides to manage pest problems. Chemical treatment is a last resort and comes with its own disadvantages. Read more about IPM
If the chemical approach is selected, the timing of the insecticide application is critical if control is to be effective. There are two approaches, preventative and curative. Preventative techniques are most effective when applied prior to when the eggs are laid, used in areas that have a history of grub infestations. The curative approach is used when an existing infestation is detected. The best time to apply curative insecticides is when the grubs are actively feeding near the soil surface. Pesticides applied any other time will be ineffective. This feeding occurs from August through October, and again in April through early May. Curative treatments applied in late summer or fall are usually more effective than spring applications because the grubs are small. Specific timing depends on the species of grub, and on location in the state.
Read more: White Grubs in Turf
Minda Daughtry is the Horticulture Agent for North Carolina Cooperative Extension in Lee County