Circular Holes in the Leaves Starting Early Summer

Q. I have begun to notice crescent shaped chunks being taken from my roses…probably at night since I do not see them during the day.In the Caribbean I notice a similar pattern on certain flowering plants which turned out to be leaf eating ants that could be traced back to their nests by following the parade of marching flower petals.We spray for ants and scorpions monthly and I have not seen any ants.From this I conclude it is a flying insect.Is there such a creature as a leaf eating BEE here in the Las Vegas Valley?If so, what should I do to prevent continued defoliation?I appreciate your advice; you have never steered me wrong.

Leafcutter or Leaf Cutter bee damage to leaves

A. Great deductive reasoning! Very close. Leafcutter bee. We tell people to leave them alone if tolerable.

http://xtremehorticulture.blogspot.com/2014/05/leafcutter-bee-perfect-circles-now-seen.html

http://xtremehorticulture.blogspot.com/2014/09/leaf-cutter-bees-destroying-leaves-on.html