We have lots of large, brown, fat beetles around our house this year. Any idea what they are, and if they are a problem for our plants and flowers?



Without actually seeing the beetles, I'd say they are some type of June beetle (Coleoptera: Scarabaeidae: Phyllophaga spp.).  There are over 150 species of May/Junebugs in North America, and they vary greatly in their size and coloration.

These beetles do feed on various shrubs and trees, so they could become a problem.  The larvae (white grubs) of these beetles feed on turfgrass roots below the soil.  If you have damage caused by these you will see irregular patches of wilting grass, eventually turning brown. If you dig into the turfgrass below one of these patches, you should see white grubs with 3 pairs of legs, and will range in size from 1 to 2 inches depending on the species of beetle. If you do not see any damage on your landscape, there is no reason for alarm.  Again, these beetles are abundant in North America and most will not cause serious damage.  They are likely being attracted to your lights at night from surrounding areas, not necessarily your yard.  You can collect the beetles and throw them into a bucket full of soapy bucket.  If you feel you have an infested lawn I can recommend some treatments.  Pleas let me know.
Please feel free to email me some more questions.

Posted on 4 Jun 2008

Ryan Davis
Arthropod Diagnostician, Utah Plant Pest Diagnostic Laboratory

Other Questions In This Topic