Chinese gall aphid

Taxonomic position. Pemphigus yangcola is a member of the order Hemiptera and the family Aphididae. It is widely recognized as a gall-forming aphid belonging to the subfamily Eriosomatinae, known for its complex life cycles involving primary and secondary host plants.

Host plants and economic impact. The primary host of this pest is the Chinese pistachio (Pistacia chinensis). The economic impact is significant in areas where pistachio is cultivated, as heavy infestations reduce plant vigor, retard growth rates, and decrease the overall yield and quality of the nut or raw material production.

Biology and life cycle. The life cycle involves a migration between hosts and the production of galls. The fundatrix (founder aphid) begins feeding on young leaves in the spring, triggering the host plant to grow a gall. Inside these protective structures, the aphids reproduce parthenogenetically, creating large colonies hidden from most predators and environmental stressors.

Nature of damage. The damage is characterized by the development of irregular, horned-shaped or bulbous galls on leaf tissues. These galls interfere with the plant’s normal physiological functions, including photosynthesis and nutrient transport. As the galls expand, the affected leaf tissue often becomes necrotic, leading to leaf drop and decreased plant health.

Control measures. Controlling Pemphigus yangcola is challenging due to the protective gall environment. Successful management involves applying systemic insecticides during the early spring window before the galls fully enclose the aphids.

• Regular monitoring of pistachio groves in early spring
• Use of systemic aphicides targeting young colonies
• Pruning and removal of galls during the early development stage