The Nutrient Composition of Three Mosquito (Diptera: Culicidae) Species, Aedes caspius, Anopheles hyrcanus, and Culex pipiens, Harvested from Rice Fields for Their Potential Utilization as Poultry Feed Ingredients

Abstract

Increasing pressure on the world’s livestock production sector has stirred interest towards the exploration of insects as an alternative feed source. We examined the potential of wild-caught mosquitoes, harvested from rice-fields, to be utilised as poultry feed. Three mosquito species were identified in high abundance, namely Aedes caspius, Anopheles hyrcanus, and Culex pipiens, and their nutritional and microbiological profile was assessed at the species-level and as mixed samples collected from two different seasons (summer 2020 and 2021). Their nutritional potential was evaluated based on protein, fat, moisture and ash content, fatty acid and mineral profile, and antioxidant activity. The microbiological profile of each mosquito species was assessed by measuring the population of total viable count, Enterobacteriaceae, lactic acid bacteria, and coagulase-positive Staphylococci. Obtained values were compared to common edible insects and conventional livestock feedstuff. All mosquito samples presented an overall promising nutritional composition, stable between the two harvest seasons. Mosquitoes’ protein and fat content ranged from 54 to 62% and 16 to 28%, respectively. The examined species presented statistically significant differences in certain cases; Anopheles hyrcanus had the highest protein content (61.8% dry weight basis; dwb) and the highest antioxidant potential (45.9% ability to scavenge the DPPH radical). All mosquito samples were rich in minerals, containing high concentrations of calcium, phosphorus, and magnesium, minerals essential for poultry development. The GC/MS fatty acid profile revealed a high unsaturated character (65.2–71.5%), a predominance of palmitic (23.8–30.4%), palmitoleic (28.5–37.0%), and oleic (18.3–29.1%) acids, as well as the presence of essential linolenic (1.4–5.2%) and eicosipentanoic (1.5–2.4%) acids. The presence of microorganisms was confirmed across all species, at levels comparable to fresh food harvested from soil and farmed edible insects. Mosquitoes harvested from rice-fields exhibited an overall highly nutritious, stable profile, comparable and even superior to common feedstuff and edible insects, showing potential to be utilised as poultry feed components.