A novel artificial diet for ants: Replacements for calcium caseinate improve colony growth in the invasive ant Nylanderia fulva

The ability to rear healthy insects under controlled laboratory conditions constitutes a key step in entomological research. In that endeavor, the design of diets is of primary importance since growth, survival and reproduction are all tightly linked to nutritional intake. The use of such artificial diets is common practice in the study of ants and many different formulations have been established. Recently, calcium caseinate, one of the main protein components of artificial ant diets has been widely phased out of production and became difficult and costly to acquire. There is thus a clear need for the identification of an adequate substitute. We compared the influence of 4 potential substitutes – sodium caseinate, whey protein, high calcium whey protein and cricket powder – to calcium caseinate on the survival and brood production of the tawny crazy ant Nylanderia fulva. This unicolonial and highly polygynous ant is a major invasive species in the southern United States and an increasing number of studies are being carried out to understand their biology and manage their populations. High calcium whey and cricket powder showed better results than the calcium caseinate control, with cricket powder showing the best results. We thus recommend the use of cricket powder as most suitable substitute. Recent trending of cricket powder as nutritional supplement has made the ingredient simple to acquire in controlled quality and affordable. The advent of insect protein as human food source offers many opportunities in insect nutrition and our study shows first positive impact of this development.