Monitoring the black fig fly (Silba adipata): Evaluating alternative monitoring techniques for a new fig pest in California

The black fig fly (BFF) (Diptera: Lonchaeidae: Silba adipata) is an invasive pest threatening fig production in California. Native to the Mediterranean and Middle East, BFF was first detected in Southern California in 2021 infesting figs grown by both hobbyists and commercial producers. Since then, it has spread throughout Southern California and the Central Coast. While the primary fig-growing region in the Central Valley (Fresno, Madera, and Merced counties) has not yet reported infestations, recent detections in adjacent counties (Sacramento and Kern) suggest its arrival is imminent.
BFF adults lay eggs in or near the ostiole of young figs. Emerging larvae feed on the syconium, halting fruit development and leading to premature fruit drop. The larvae then pupate in the soil after exiting the figs. Since much of the lifecycle of the BFF is hidden in fruit or the soil, effective adult monitoring is essential for developing integrated pest management (IPM) strategies for this pest.
Currently, monitoring methods are difficult to use and unselective. McPhail-type traps baited with torula yeast are the most commonly used because they are attractive to BFF adults. However, these traps also capture large numbers of non-target species, complicating BFF identification efforts. In 2025, we conducted a series of studies evaluating alternative lures designed to improve specificity and reduce bycatch. Here, we present the preliminary findings and outline plans for future research.