little green leaf-eating worms
My friend's fruit trees (2 apples and 2 pears) have been getting munched by tiny green worms. They are chewing holes through the leaves.
Is BT what you'd use to kill these cute little buggers off? Does anyone know what these worms are, exactly? Is this a problem that's to be expected and controlled each year?
Zone 6a, full sun, good well-drained soil. Trees purchased and planted in April of this year, 7 gallon pots.
Thanks in advance for any help.