Abstract:
The effective mass rearing of Helicoverpa armigera under laboratory conditions is essential for numerous
entomological research and pest management programs, such as biocontrol studies, resistance identification,
toxicology bioassays, and integrated pest management strategies. This study aimed to develop and optimize a cost
effective, nutritionally balanced semi-synthetic diet for rearing H. armigera larvae at the Horticultural Crops
Research and Development Institute (HORDI). Initially, four semi-synthetic diets with wheat, mung, chickpea,
and corn flours as the main ingredients were evaluated alongside cabbage leaves and soaked-chickpea natural
diets. Growth and reproductive parameters such as larval and pupal durations, larval and pupal weights,
pupation and moth emergence percentages, and moth fecundity were assessed. Results revealed that mung bean
and chickpea flour diets significantly outperformed the others, resulting in shorter larval and pupal durations,
higher survival rates, and greater fecundity. Although mung bean flour yielded slightly better results than the
chickpea flour diet, the chickpea diet was selected as the optimal main ingredient for the semi-synthetic diet due to
its lower market cost. Subsequently, the chickpea diet was modified by replacing costly laboratory-grade
ingredients, such as yeast extract, sucrose, and agar, with food-grade alternatives, such as instant dry yeast, sugar,
and gelatin or agar-agar, in two modified diets. Of the two modified diets, the one using agar-agar (modified diet
1) showed comparable results to the original in all measured parameters, while the gelatin-based diet (modified
diet 2) showed slightly delayed development and lower moth emergence, possibly owing to its stickiness, due to
instability in room temperature. The study concludes that the chickpea-based semi-synthetic diets, particularly
the modified version using cost-effective alternatives and food-grade agar-agar, offer a reliable, economical, and
efficient solution for mass rearing H. armigera larvae under local laboratory conditions.
