Hackberry aphid

Systematic position: The hackberry aphid (Shivaphis celti) belongs to the order Hemiptera and the family Aphididae. It is a specialized pest species that specifically targets trees of the genus Celtis, commonly known as hackberry trees, and is found in various regions where these trees grow.

Host plants and damage: The primary host is the southern hackberry (Celtis australis). The aphids colonize the undersides of leaves, extracting vital plant sap. This process leads to leaf discoloration, premature yellowing, and eventual leaf drop, which can significantly stunt the growth of young or weakened trees.

Biology and life cycle: The life cycle is complex, involving several generations of both winged and wingless individuals. The species overwinters as eggs deposited in the bark crevices of the host tree. With the arrival of spring and rising temperatures, the eggs hatch into nymphs, which begin feeding on developing foliage immediately.

Character of damage: A significant consequence of infestation is the production of copious amounts of honeydew. This sticky substance serves as a growth medium for sooty mold fungi, which coat the leaves in a black, powdery layer. This layer blocks light, inhibiting photosynthesis and causing further stress to the tree's physiological processes.

Control measures: Effective management requires regular monitoring and timely intervention. Chemical control involves the application of systemic insecticides during the early stages of infestation. Preventive measures, such as maintaining overall tree health through proper irrigation and nutrition, also help the trees withstand aphid pressure better.

• Pruning heavily infested branches to reduce population density.
• Applying horticultural oils to smother overwintering eggs.
• Encouraging the presence of natural predators like lady beetles and lacewings.
• Using contact or systemic insecticides during the active growing season.