Pearslug (Cherry slug)—Caliroa cerasi
Adult pearslugs are small, glossy black sawfly wasps about 0.2 inch long. The newly hatched larvae are
white with a yellowish brown head. Almost immediately after hatching, the larva exudes an olive green
coating that covers its body and gives it the appearance of a slug. The head end is wider than the rest
of the body and a fully mature larva is about 0.5 inch long.
Larvae skeletonize leaves and may remove all tissue except for the fine network of veins. Leaves with
brownish patches result from the top layer having been eaten. High populations may reduce fruit size.
Pick pearslugs off by hand and dislodge them from foliage
with a strong stream of water. Spinosad or insecticidal
soap may be effective. Road dust or ash applied to foliage
has been effective in killing pearslugs. Such dusts should
be washed off after several days to discourage spider mites.