We introduce a novel method for quantifying the response of tephritid fruit flies to chemical attractants (lures) under seminatural conditions by using automated detection and quantification via computer vision and an interruptible lure apparatus. We use this method to obtain a high-resolution (0.1 Hz) dataset representing the response of colony-reared melon flies, Bactrocera cucurbitae Coquillett, to cuelure [1-(p-acetoxyphenyl)-butan-3-one] at three different times of the day: morning (0900–1000 hours), mid (1200–1300 hours), and afternoon (1500–1600 hours), or all three times combined. Results consistently show a high and sustained response to cuelure in the morning period, a high but quickly decreasing response during the middle of the day and a low response in the afternoon. We propose possible reasons for the difference in response between the morning and middle of the day periods that could be investigated in future studies. The approach used here also can be used to study other important questions on the biology of tephritid fruit flies and other insects of similar size, particularly those involving their response to chemical lures.