June beetles are a type of large, dark brown scarab beetle represented by 150 different species found all across Canada. They complete their life cycle over three years, with the adults first emerging from the soil in May or June. After mating, the female beetle will fly to a grassy area and burrow underground to lay her eggs. The grubs hatch within a few weeks and feed on plant roots and decaying organic matter for the rest of the summer. When the temperature drops, the grubs burrow further underground to overwinter. The following spring, they return to the soil surface and feed voraciously on roots; June beetle larvae cause the most damage in the second year of their life cycle. In the fall, they burrow downwards to overwinter, again, and return to the surface once more the following spring. In their final year of development, the grubs will only feed for a few weeks before pupating. The pupae then lay dormant until the new adult beetles finally emerge the next spring to begin the cycle again.
What kinds of plants do they attack?
June beetles are mostly a problem for grass and turf as white grubs, when they’re in their larval stage. However, the adults feed on the foliage of broad-leafed trees and shrubs and can also cause considerable damage. When present in large numbers, they can strip leaves from aspen, chestnut, elm, maple, oak, poplar and willow trees, as well as from shrubs, roses and raspberries.
What do they look like, and how do I know if my plants are under attack?
Please consult the general information on white grubs.
How to get rid of June Beetles / Grubs
Koppert offers different solutions for biological pest control of June Beetles / Grubs.