Sustainable protein and waste management using insects

Abstract

Insects are often viewed as pests in conventional agricultural production but have the opportunity to become farmed commodities and allies in solving persistent agricultural challenges. The growing global population will require sustainable and innovative protein sources to meet rising nutritional demands. An option for protein that requires little space, water, and inexpensive feed could be insects. Insects such as Tenebrio molitor (yellow mealworm), Alphitobius diaperinus (lesser mealworm), Hermetia illucens (black soldier fly), and Acheta domesticus (house cricket) have shown promise as efficient consumers and could be waste upcyclers which turn agricultural and municipal waste products into high-protein biomass suitable for livestock, aquaculture, and potentially human consumption. Despite their potential, challenges remain in optimizing rearing practices, particularly with respect to feed type, density, and environmental conditions, to scale insect production effectively. In Chapter 1, I explored a quantitative literature review to examine the influence of density-dependent and -independent factors on farmed insect mass and survival. The lesser mealworm has been the most recent insect of interest as a waste upcycler. While widely known as a significant pest of poultry, their association with animal manure may offer a pathway for sustainable waste reduction and protein generation. In Chapter 2, using agricultural and municipal waste as feed substrates, I studied the growth performance of the lesser mealworm at different rearing scales, bridging gaps in knowledge between scaling up production and optimizing rearing conditions in controlled environments. In addition to converting waste into insect biomass, insects may alter their waste substrates in ways that are beneficial for agriculture. For instance, parasites often spread through animal manures, yet the role of manure-feeding insects, like black soldier fly larvae, in reducing these parasite loads may be underappreciated. In Chapter 3, I conducted controlled feeding bioassays to examine the effect of black soldier fly larvae on nematode parasites in horse manure. Ultimately, my work presents a snapshot of the potential solutions that insects offer to address global challenges in food security, waste management, and parasite control, building toward sustainable and scalable agricultural practices.