Wattle bagworm

Systematic position. The Wattle bagworm, Kotochalia junodi, is a member of the Psychidae family within the order Lepidoptera. This insect is widely recognized for its unique life strategy, where the larvae construct protective cases (bags) made of silk and vegetable debris. These cases serve as a portable shelter throughout the larva's development, providing protection against predators and environmental stress.

Host plants. While predominantly known as a major pest of tea plantations (Camellia sinensis), Kotochalia junodi is a highly polyphagous insect. It causes significant economic damage to various forestry plantations, particularly wattles (Acacia species) and eucalyptus trees. Its ability to feed on a wide variety of woody plants makes it a persistent threat in both agricultural and silvicultural settings.

Biology and life cycle. The species undergoes a complete metamorphosis. One of the most distinctive features is the extreme sexual dimorphism: adult females are flightless and remain within their larval cases throughout their adult lives. In contrast, males are winged and highly active, flying to locate females for mating. Eggs are deposited within the female's case, where the next generation begins its life.

Damage and impact. The larvae are responsible for the damage. They consume the leaves of the host plants, which can lead to severe defoliation if infestation levels are high. Heavy feeding reduces the plant's capacity for photosynthesis, stunts overall growth, and drastically lowers the yield of commercial products. In tea production, this leads to significant economic losses and weakened plant vitality.

Control measures. Successful management relies on an integrated approach.

• Manual collection and destruction of the bagworms in smaller infestations.
• Application of biological control agents, such as specific nuclear polyhedrosis viruses (NPV).
• Use of selective insecticides during the period when young larvae are emerging and susceptible.
• Fostering natural enemies, including parasitoid wasps, which play a crucial role in suppressing population outbreaks.