Orthaga euandrusalis

Systematic position: Orthaga euandrusalis belongs to the order Lepidoptera, family Crambidae. Known commonly as a mango leaf webber, this moth is recognized as a significant pest in mango-producing regions across Asia and the Pacific, capable of causing localized outbreaks that devastate orchard foliage.

Host plants: The primary host for this species is the mango tree (Mangifera indica). While it is highly specific to mango, the pest can severely impact both young nurseries and mature fruit-bearing orchards, showing a preference for fresh leaf flushes which are crucial for the tree's photosynthesis and development.

Biology and life cycle: The moth follows a holometabolous life cycle: egg, larva, pupa, and adult. The female moths deposit eggs on the leaf surface. Upon hatching, the larvae create webbed nests by binding leaves together with silk secretions. These nests act as a protective micro-environment where the larvae feed in groups, remaining shielded from environmental stressors and predators.

Damage and economic impact: The larvae feed on leaf tissue, resulting in skeletonized leaves that eventually turn brown and wither. Severe infestations cause extensive defoliation, which severely hampers the tree's ability to produce energy. If left unchecked, persistent outbreaks lead to stunted growth, reduced fruit set, and significant economic losses for commercial mango growers.

Pest management: Control strategies require a combination of vigilance and chemical intervention.

• Mechanical control: Pruning and burning the webbed nests during the early stages of infestation.
• Biological control: Encouraging natural parasitoids and predators that target the larval stages.
• Chemical control: Targeted application of broad-spectrum or systemic insecticides during the peak larval stage to reduce population density.
• Monitoring: Regular scouting of orchards to identify nests before they spread across the entire canopy.