Twelve wild introductions of Solanum section Lycopersicum were evaluated to determine their resistance to tomato fruit borer Neoleucinodes elegantalis. The introductions PI 134417, PI134418 and PI 126449 of Solanum habrochaites var. glabratum, the introduction LA 1624 and LA2092 of S. habrochaites var. typicum, and the introduction LA 444-1 of S. peruvianum, presented high resistance to the tomato fruit borer of tomato N. elegantalis. Genetic introgression of resistance to tomato fruit borer in the introduction PI 134418 S. habrochaites var. glabratum was performed to cultivated Unapal - Maravilla of S. lycopersicum. It was found highly significant positive association between the damage caused by pest insect and fruit weight, as it regains the fruit weight of cultivated Unapal - Maravilla (recurrent progenitor), by successive back-crossing, it lowers resistance to pest insect. Trichomes and fruit number by cluster did not affect the infestation and fruit damage by the insect, while fruit weight had significant impact because it tends to cause greater damage as it increases fruit weight. The backcrossing method was effective in breaking the association between the fruit weight and resistance to insect. RC2 recombinant plants were obtained with resistance to tomato fruit borer and fruit weights between 45,1 and 68,6g.