Antibiosis in Lycopersicon to the Tomato Fruitworm (Heliothis zea)1

Leaves of Lycopersicon hirsutum Humb. & Bonpl. and L. hirsutum f. glabratum C. H. Mull, contained a factor highly antibiotic to tomato fruitworm, Heliothis zea (Boddie), larvae. The factor was extractable with ethanol and lethal to larvae fed on an artifical diet containing the extract. The antibiotic factor appeared to be inherited recessively. Because the early instars of H. zea larvae on tomato, L. esculentum Mill., plants depend on leaf tissue rather than fruit as a primary food source, this antibiotic factor may be a valuable source of resistance for commercial cultivars.