In mass-rearing for management of Mexican fruit flies (Anastrepha ludens) and Mediterranean fruit flies (Ceratitis capitata) using sterile insect technique, technicians must determine the correct time to irradiate by taking a sample of pupae, removing the pupal case to expose the eyes, and then checking the eye color of the pupa against a color chart. Researchers in Mexico have applied machine-learning algorithms to conduct this step. Shown here are pupae of both species according to physiological age and days until emergence. Emergence refers to pupae emerging or about to emerge. Both species are irradiated two days before emergence. (Image orginally published in González-López et al 2022, Journal of Economic Entomology)