Injury to NH Apple Foliage and Twigs

 

Tarnished Plant Bug: Opening buds that have been attached often drip or ooze liquid. Individual flower buds sometimes die, while those that escaped the attack survive.

Apple blotch leafminer and Spotted tentiform leafminer: These insects are nearly identical in appearance and injury. Eggs are very difficult to see. They are flat like pancakes, laid individually on the underside of leaves, especially cluster leaves. They are nearly transparent, colorless. Sap-feeding larvae feed just under the cuticle of the underside of the leaf, separating it from the middle spongy mesophyll layers of the leaf. The area looks slightly silvery, if you look at it correctly in the light. Tissue-feeding larvae are older, and switch to feeding on the spongy mesophyll layer. They feed a bit in one spot, then move slightly to the side. This makes “spots” that are visible from the upper leaf surface. The mine puffs out a bit, so is shaped like a tiny tent.

Appleleaf Trumpet Leafminer: The larvae (caterpillars) are very tiny, and feed between the layers of leaves. Mines start out as sinuous, narrow curves, and as the larva gets older, turn into a brown blotch visible from above.

White apple leafhopper and Rose leafhopper: Both the nymphs and adults feed on foliage with piercing-sucking mouthparts. Feeding causes a white stippling on leaves. Fecal droppings are brown liquid, and fall on leaves (or fruit) immediately below.

Potato leafhopper: Shoots and suckers are strongly preferred over other plant parts. Affected leaves become slightly cupped. Then the edges turn yellowish, then dry and brown. Shoots with these leaves are stunted.

Green Pug Moth: The caterpillars feed in early spring, and stop at petal fall. Flowers that have stamens and pistil chewed away are signs of this insect. Yes, some other insects sometimes do this.

Caterpillars: Several species feed on apple foliage, including Eastern tent caterpillar, forest tent caterpillar, redhumped caterpillar, cecropia moth, climbing cutworms, and green fruitworm.

Fall Webworm: Hairy caterpillars are in large groups, within large webs of silk that enclose foliage (sometimes fruit, too).

Oystershell scale: bark is covered with tiny gray scales shaped like oyster shells.

San Jose Scale: Bark has tiny circular scales, especially in protected spots.

Cedar-Apple Rust: When the fungus attacks leaves, the lesions look like orange spots.