Apple leafhopper

Taxonomic position. The apple leafhopper (Empoasca maligna) belongs to the order Hemiptera and the family Cicadellidae. It is a recognized pest in apple orchards, causing physiological stress to the host trees through its specialized feeding habits.

Host plants and damage. The primary host is the apple tree. Both adults and nymphs feed on the phloem sap of the leaves. Feeding causes chlorotic spots that eventually turn necrotic. This damage inhibits the plant's ability to conduct photosynthesis, leading to reduced overall tree vigor and lower fruit quality.

Biology and life cycle. The species overwinters in the egg stage, with eggs embedded just beneath the bark of young twigs. Nymphs emerge in the spring and move to the undersides of the leaves. There are typically one to two generations per year. Adults are highly mobile and will quickly jump or fly when the foliage is disturbed.

Nature of injury. Symptoms include stippling on the leaves, curling of the margins, and premature defoliation. A heavy infestation can result in stunted growth and a decline in the tree's winter hardiness. Young trees in nurseries are particularly susceptible to severe damage, which can lead to significant economic losses for growers.

Control measures. Integrated pest management strategies are essential for effective control. Growers should consider the following:

• regular monitoring of leaf undersides during the spring;
• pruning and disposing of infested shoots;
• applying systemic insecticides during the peak nymph stage;
• maintaining healthy tree nutrition to increase resistance to pest damage.