Standardising artificial diets for mass-rearing insects
in laboratory is crucial for deepening our understanding
of insect biology, behaviour and nutritional needs, which
are pre-requiste for developing effective integrated
pest management strategies. The present study was focused on formulating an optimal artificial diet for the
invasive pest Spodoptera frugiperda by evaluating various
diet ingredients and their impact on insect development.
Out of 32 diet compositions tested, 16 diets supported
developments to the adult stage and these 16 diets were
further evaluated to identify the best-suited diet. Among
these, a diet based on lab lab beans emerged as the
most effective for rearing fall armyworm in the laboratory. Larvae fed with a diet of lab lab beans soaked
and supplemented with maize leaf powder, excluding
Wesson’s salt, achieved the highest larval weight
(0.3807 g on the 7th day after hatching), the shortest
larval duration (14.47 days), the highest pupal weight
(0.2520 g), the shortest pupal duration (10.03 days) and
the highest adult emergence rate (94.50%). These results were comparable to the diet of soaked lab lab
beans without maize leaf powder and Wesson’s salt,
which recorded a larval weight of 0.2343 g, a larval
duration of 15.50 days a pupal weight of 0.2107 g, a
pupal duration of 10.25 days, and an adult emergence
rate of 93.00. The addition of Wesson’s salt did not
significantly enhance growth parameters. Although the
diet including maize leaf powder supported the highest
adult emergence, its cost and the difficulty of sourcing
pesticide-free maize leaf powder make it impractical.
Therefore, the diet without maize leaf powder has been
standardized as the most efficient and reliable method
for producing a large and continuous supply of insects
for research purposes. This optimized diet not only ensures the robust growth and development of S. frugiperda but also provides a cost-effective and practical
solution for laboratory rearing, significantly advancing
research capabilities in pest management.