Wormwood gall mite

Systematic position. The wormwood gall mite (Latin: Eriophyes annui) belongs to the order Acariformes, family Eriophyidae. These microscopic arthropods are highly specialized parasites characterized by a worm-like body shape and two pairs of legs, which distinguishes them from other groups of mites commonly found in agricultural fields.

Host plants. The primary host for Eriophyes annui is annual wormwood (Artemisia annua). As this plant is widely cultivated for the industrial extraction of artemisinin, the mite poses a significant risk to pharmaceutical raw material production, potentially impacting yield and quality.

Biology and life cycle. These mites overwinter as adult females in buds or under the bark of the host plant. With the onset of spring temperatures, they emerge to feed on developing leaves and shoots. The life cycle involves several overlapping generations throughout the growing season, with development rates highly dependent on ambient temperature and host plant physiological state.

Damage and economic impact. Feeding by Eriophyes annui induces the formation of galls — abnormal growths caused by saliva-injected enzymes. This damage disrupts nutrient transport and photosynthesis, leading to leaf distortion, stunted growth, and reduced biomass. Heavy infestations can lead to significant quantitative losses in harvested medicinal biomass.

• Early field monitoring for symptoms.
• Application of specialized acaricides.
• Destruction of crop residues post-harvest.
• Crop rotation to break the mite life cycle.
• Selection of resistant or healthy planting material.

Control measures. Managing this pest requires a combination of cultural and chemical practices. Because of the mites' protective gall formations, chemical intervention is most effective during the early stages of colonization before the plants are heavily deformed. Cultural practices, such as removing infected parts and proper field hygiene after harvest, are essential to minimize the overwintering population for the next season.