Jackfruit, Artocarpus heterophyllus Lam., in Mexico is a recent crop for the export market. The branch borer, Neoptychodes trilineatus L., is the main pest of the crop. The objectives were to determine the incidence of larvae in branches and severity, spatial distribution, and population fluctuation of adults at Nayarit, Mexico in 2018-2019. Adults feed on tender shoots and skin of developing fruits, while larvae bore the branches. With an average incidence of two larvae per kilogram of wood, they were found throughout the year, except in December. The greatest infestation occurred in September with 5.4 larvae per kilogram of wood. Eighty-five percent of the trees showed symptoms of borer damage, with a mean incidence of 0.92 adult per tree. Adults were collected in April, May, July, August, November, January, and February. In January, the largest infestation was detected with three adults per tree. The greatest presence occurred in the Tecuitata region with 1.7 adults per tree, and 1.1 at Jalcocotan.