The tomato fruitworm, Helicoverpa armigera (Hubner), is a major pest in processing tomato crops in Tunisia. The dynamics of fruitworm populations in the field is important in order to enhance the efficiency of insecticides. Seasonal activity was studied by sampling methods on foliage and by pheromone traps over a three year period. Two traps were located within each tomato crop in the Tunisian regions: Korba and Manouba. Weekly catch data showed that moths were active from late May to early November and the maximum trap catch occurred in July. Egg and larval populations were also counted on a weekly basis on 30 sampled leaves. The greatest number of eggs and larval stages were observed in July which coincides with the maximum moth activity. These observations allowed us to realize the control assay in late June. Two chemicals, methomyl and endosulfan, along with two biological insecticides, Bacillus thuringiensis and Melia azedarach suspension were used. Spraying application started when catch traps reached 5 moths/day/trap. Results of the two years experience showed that applications of both B. thuringiensis and M. azedarach suspension reduced pest populations and were comparable to methomyl, the chemical standard. This is a promising result for use of biological control agents in tomato crop protection.