Question
Hi,
I have a green ash, about 35 yrs old, (I live in Calgary, Alberta Canada)the tree looks good but when you get up close you see that most of the leaves are folded in half or curled, they are still green and don't look different otherwise.  When you unroll the leaf there is a, it almost looks like the seed pod off of a piece of wheat.  I cant seem to find anything like this in the chats, can you help me?  Thanks!

Answer
Ash leaf-roller enjoys leaves of all ash species, including green ash (Fraxinus pennsylvanica), black ash (F. nigra), Manchurian ash (F. mandshurica) and white ash (F. americana). Mountain ash (Sorbus spp.) is not relatedand is not affected by this insect.

Ash leaf-roller is native to the eastern United States and Ontario and Quebec and has been noticed in the prairie provinces since 1999, when it was discovered in Edmonton. Since then it has showed up in all the prairie provinces, but done no real damage. Apparently because of the very cold winters, it has not managed to establish a firm foothold in the region.

The moth of the ash leaf roller is one of the earliest insects that an observant gardener notices in spring. The overwintering moths mate in spring and lay eggs on newly emerging ash leaves. Upon hatching, the teensy caterpillar wastes no time exposed to the elements and hungry predators, but moves under the surface of the leaf. Meandering trails just under the upper surfaces of ash leaves early in June reveal their presence. As the caterpillars get bigger, their subsurface feeding causes larger leaf blotches.

In late June caterpillars abandon the protection of their mined leaves and descend on silken threads to fresh leaves. These caterpillars roll an ash leaflet into a triangular cone and feed inside the cone on the inner edges of the leaf. Pupation takes place in spindleshaped cocoons within the protection of the leaf curl.

The adult moth emerges from the cocoon about two weeks later, in mid-July. The adult is a tiny moth that at a casual glance looks like a rather fat mosquito, but it is harmless. Its wings are folded cylindrically along the body. It is propped up at an angle by its long front legs, giving it the nickname 損ush-up?moth.

In the heat of late summer, these tiny moths become scarce, probably seeking resting spots until the weather cools in September, when they appear again for a short period. Real cold forces them to find safe overwintering sites.

Most people notice these little insects when they are at the leaf-rolling stage. Since rolled leaves take up less space than flat leaves, the tree looks as if it has lost foliage. It is alarming when most of a tree抯 leaves are transformed into little triangular cones like millions of dangling earrings. But the leaves remain green and are mostly intact, so they are still useful to the tree.

There is little point to spraying with pesticides. The caterpillars can抰 be reached by such crude methods because they remain hidden inside the leaf. They are parasitized by several species of solitary (non-stinging) wasps, so it抯 best to let natural forces work themselves out. They really do little real damage. I would fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. This will help the tree overcome the loss of some foliage area.