Effectiveness of Colored Plastic Bottle Traps With and Without Methyl Eugenol For Monitoring Fruit Flies [Bactrocera Spp.] in Chili Fields of Tarakan, Indonesia

Fruit flies (Bactrocera spp.) are economically important pests of chili and other horticultural crops. This study compared captures in recycled plastic-bottle traps containing yellow, green, or white paper inserts at three selected chili-growing sites in North Tarakan, North Kalimantan, Indonesia. Trapping comprised an unbaited stage followed by a stage with methyl eugenol (Petrogenol); observations were indexed from Day 1 to Day 5. Cumulative fruit-fly catches across the three sites were 18, 2, and 0 in unbaited yellow, green, and white traps, respectively, and 213, 18, and 32 in the corresponding baited traps. Bactrocera dorsalis and Bactrocera umbrosa were recorded. Baited yellow traps captured 193 B. dorsalis and 20 B. umbrosa. Yellow traps had the highest observed catches in both stages. Because the stages were sequential, differences between stages cannot isolate the effect of methyl eugenol or establish a color-by-lure interaction. The short observation period and unresolved sampling-effort details further restrict inference. Yellow bottle traps with methyl eugenol warrant further evaluation for monitoring responsive Bactrocera species in these fields; the study does not establish reduced fruit damage, population suppression, or increased yield.