Black turfgrass ataenius

The adult black turfgrass ataenius beetle is 0.2 inch (5 mm) long, shining jet black, and has parallel grooves on the wing covers (elytra). Adults can be seen any time of day, especially on golf course greens and tees. Adult black turfgrass ataenius can easily be mistaken for another beetle, Aphodius lividus (not known to damage turf), which is slightly smaller and chocolate brown with straw-colored stripes near the center of the back and along the margin of the elytra.
Female ataenius adults burrow into the thatch and upper soil where they lay clutches of 11 or 12 eggs. Eggs hatch into scarab grubs, which can be distinguished from other white grubs by their small size, the scattered pattern of bristles on the last abdominal segment, and a pair of pads at the tip of the abdomen. At least two or three generations develop in California each year with up to five in the warmest part of the state. Adults are continuously active during warm months in inland areas. They probably overwinter in a reproductive dormancy.