Can crickets recognise bacterially contaminated feed? Gryllus assimilis odour perception of Escherichia coli

Abstract

Edible crickets Acheta domesticus and Gryllus assimilis are worldwide mass-reared insects. They are recognised as a sustainable source of protein in the food and feed industries and, in relation to this, must comply with food safety requirements. In this study, we assessed the self-protective ability of crickets to recognise potentially hazardous bacteria-contaminated feed. A two-choice test was carried out to estimate the crickets’ preference between the bacteria-contaminated and control feed. Three bacterial species were tested as potential contaminants: Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis. A. domesticus did not recognise feed contaminated with any of the bacterial species tested. G. assimilis avoided E. coli-contaminated feed, while the other two bacteria did not cause differences in feeding behaviour. The study of gas chromatography-electroantennogram detection showed that E. coli released a volatile compound, which was olfactory perceived by both males and females of G. assimilis. The compound was identified as indole. In a behavioural test, crickets spent less time feeding on indole-contaminated feed compared to control feed. Hence, indole induced an avoidance response in G. assimilis. It can be concluded that G. assimilis perceives and recognises some bacteria contaminants and thereby avoids spoiled feed.

The Fatty Acid Compositions, Irritation Properties, and Potential Applications of Teleogryllus mitratus Oil in Nanoemulsion Development

“…However, three major species widely consumed and farmed in Thailand included Gryllus bimaculatus (two-spotted cricket or field cricket), Teleogryllus mitratus (ground cricket), and Acheta domesticus (house cricket) . G. bimaculatus is also the main cricket species used for research in the United States and Japan [ 6 ], whereas another worldwide popular species is A. domesticus [ 7 ]. In addition to being a good source of protein and essential amino acids, crickets are a good source of lipids and fatty acids, particularly PUFAs, which have advantageous health benefits, and were thus suggested to be incorporated into routine diets to maintain health [ 8 ].…”