Holes in rose leaves

The shape of the damage points to the culprit, so look at the leaf before you look for an insect. See-through windows grazed between the veins, a leaf eaten to lace between its veins, ragged holes chewed through, and neat semicircles cut from the margin are different animals at work, and the one cutting semicircles is a bee you should be pleased to have. Much of it looks worse than it is: the RHS says roses usually recover from rose sawfly defoliation with no effect on flowering, and that leafcutter bee notches do not usually affect the plant's vigour.

1. Rose sawflyEndelomyia aethiopsAlso commonA small, pale green, slimy-looking larva, about ½ inch when grown, grazes away one surface of the leaf between the veins. It leaves see-through windows that turn white and then brown. UC IPM adds that roseslugs as a group chew larger holes as they mature. It is a sawfly, not a caterpillar, so Bt does nothing to it; pick the larvae off by hand or wash them off with a strong jet of water.Full pest profile →
2. Japanese beetlePopillia japonicaAlso commonMetallic green with copper-brown wing covers, active on warm, sunny days and feeding in groups. They chew out the tissue between the veins until the leaf is a lace-like skeleton, and they eat rose petals too. Skip the traps: Kentucky Extension found they attract many more beetles than they catch.Full pest profile →
3. Rose chaferMacrodactylus subspinosusLess oftenSlender, pale green to tan, with long, spiny, reddish-brown legs, out from late May through June and worst on sandy sites. Large, irregular holes in the blooms, and leaves skeletonised between the veins. Feeding lasts only three to four weeks.Full pest profile →
4. EarwigsForficula auriculariaLess oftenHarmlessIrregular holes in leaves and petals that appear overnight, with nothing to be seen by day. Earwigs chew many garden flowers, but neither UC IPM's rose guide nor the RHS names them as a rose pest, so check by torchlight after dark before you blame them. They also eat aphids, which is why UC IPM makes trapping, not spraying, the answer.Full pest profile →