14 July 2024

Yesterday in my sister’s backyard in Tidewater Virginia we watched about a hundred green beetles flying rapidly in wide circles over the grass. They moved so fast that we couldn’t see their features but we could tell they were big, 1/2 to 1 inch long. None of us had ever seen this phenomenon before.

I couldn’t identify the beetles until one landed in the grass and I saw it through binoculars. I did not record this video but this is what I saw.

An online search found an August 2023 report from WDBJ in Roanoke VA “You may be seeing more shiny, green beetles this year.” It identified them as green June beetles (Cotinis nitida). They are harmless to humans.

Green June beetles are members of the scarab beetle family, same as the dung beetles of Africa, sacred in Ancient Egypt. Though these are called “June” beetles, July and August are the adults’ most active time. Males fly around seeking females. Females fly low over the grass looking for a place to lay eggs. So that’s what we were seeing.

When the eggs hatch the larvae tunnel underground and emerge at night to travel on their backs, waving their legs in the air. This sounds like odd and hazardous behavior.

North Carolina State Extension says the third instars “produce a secretion that binds soil particles together and enables them to form a protective case in which they overwinter in the soil.” The beetles pupate and emerge as adults in the summer.

Their dirt ball reminds me of the dung beetle. The photo shows one open with pupa inside.

Though we saw a lot of bugs yesterday it may not turn into many down the road. The grubs have many predators so North Carolina State Extension’s residential recommendation is: “If there is no indication of turf damage due to tunneling by the grubs, no action is really necessary.” 

Green June beetles occur in Pittsburgh, even in Schenley Park, though not often (click here and here to see two iNaturalist entires). I have never noticed their courtship behavior in Pittsburgh.

Their occurrence map indicates that green June beetles are much more common in Virginia.