Nutritional Value of the Maize Stalk Borer and American Bollworm as Unconventional Protein Sources

Abstract

Problem statement: The maize stalk borer and American bollworm were grown in an artificial media to evaluate their potential as human food sources. Approach: Both cultures were started from moths and the life cycle and culture structures were evaluated. Results: The larvae of both insects reached maximum weight and maximum length at the same time. The growth rate of the youngest larvae was found to be the highest and the increase in the body weight during the growth period appeared to be linear. The larvae of these insects started to decrease in weight after they reached the maximum size. For efficient systems for the commercial production of the maize stalk borer and the American bollworm, the larvae should be harvested when they are 39 and 21 days old, respectively. The protein contents were 38.0 and 33.0% and the fat contents were 14.5 and 14.4% for the dried larvae of the American bollworm and maize stalk borer, respectively. The larvae of both insects contained the essential amino acids and minerals. Only 10% mortality was observed with older larvae of both species. A system where eggs are separated from adults and hatched in separate chambers would alleviate the possible danger of losing the population due to microbial infection. The high moisture content of the larvae (60.4-61.0%) could cause handling and storage problems. Drying and grinding the larvae would reduce them to easily manageable forms and would improve their marketability as novel food. Conclusion: The results obtained from this study show the potential of using insects as a protein source for human consumption to alleviate protein deficiency in many parts of the world, especially in Latin America, Africa and Asia. Further research is required to evaluate their growth characteristics on low substrates. Future research should also evaluate environmental parameters such as temperature, relative humidity and heat and CO₂ production on food consumption and protein yield per gram substrate. This information will aid in the design of optimal production systems.