Spruce long-legged aphid

Systematic position. The spruce long-legged aphid (Lachnus longipes) belongs to the order Hemiptera, family Aphididae. It is a specialized pest that infests coniferous trees, specifically targeting various species of spruce (Picea), playing a significant role in forest and ornamental plant health.

Host plants and damage. This species primarily infests spruce trees. The aphids feed on the sap of young shoots and needles. Typical symptoms of infestation include needle yellowing, curling, and premature shedding. The secretion of honeydew promotes the growth of sooty mold, which creates a dark film on the needles, interfering with photosynthesis.

Biology and life cycle. The life cycle typically begins with overwintering eggs laid on the needles or bark. In spring, the nymphs hatch and begin feeding, producing several generations of wingless and winged individuals. Rapid population growth can occur during warm and dry spring months, leading to intense outbreaks on host trees.

Economic impact. The pest is particularly harmful to young spruce trees in nurseries and young plantations. Heavy infestations result in reduced growth rates, loss of vigor, and poor aesthetic quality. Furthermore, weakened trees become more susceptible to other forest pests, such as bark beetles, and various pathogenic fungi.

Control measures. Integrated pest management strategies are recommended:

• Regular field inspections to monitor aphid activity during the budding season.
• Application of selective systemic or contact insecticides when population thresholds are exceeded.
• Conservation and encouragement of natural enemies such as ladybeetles, lacewings, and hoverflies.
• Maintaining tree health through proper fertilization and watering to improve natural resistance.