Symptoms and Infestation Levels of the Emerging Coffee Leaf Miner Pest in Bandung Regency

Abstract

The coffee leaf miner is an emerging threat to coffee cultivation in Bandung, West Java. Despite its potential impact, there is a significant knowledge gap regarding the identity and ecology of leaf-mining insect species affecting coffee plants in this region. To address this issue, a research initiative was conducted to document the occurrence, distribution, and impact of leaf miners in coffee plantations within Bandung Regency. The objectives of the study were to characterize the symptoms of infestation and quantify the extent of foliar damage under field conditions. Study sites were selected through purposive sampling, based on reports from local coffee farmers regarding suspected leaf miner activity. Damage intensity was assessed using a standardized scoring system, while damage severity was quantified using a systematic diagonal sampling method. The survey confirmed the presence of leaf miners belonging to the family Gracillariidae (Lepidoptera), representing the first recorded incidence of this group affecting coffee crops in the Bandung region. All coffee plants surveyed in the study plots exhibited signs of infestation, with the maximum recorded mean damage severity reaching 25% leaf area loss. These findings enhance the understanding of leaf miner pest dynamics in Indonesian coffee agroecosystems and offer a valuable reference for the development of targeted monitoring systems and integrated pest management (IPM) strategies.