Submitted to: Insectes Sociaux
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/27/2014
Publication Date: 6/27/2014
Citation: Gavilanez Slone, J.M., Porter, S.D. 2014. Laboratory Fire Ant colonies (Solenopsis invicta) fail to grow with Bhatkar Diet and three other artificial diets. Insectes Sociaux. 61:281-287. Interpretive Summary: Artificial diets are often used for rearing ant colonies in the laboratory because they are convenient and recommended in the scientific literature. Unfortunately, popular artificial diets have not been properly tested to show that they can produce healthy growing colonies under laboratory conditions. In order to remedy this problem, scientists in the Fire Ant and Household Insects Research Unit of the USDA-ARS Center for Medical, Agricultural and Veterinary Entomology in Gainesville, FL examined growth of red imported fire ant colonies on four artificial diets: 1) an experimental predator diet, 2) an agar diet with vitamins, honey, and raw eggs (Bhatkar Diet), 3) an agar diet with honey, whey protein, egg powder, calcium caseinate, and insect vitamins (Dussutour Diet), and 4) a completely chemically defined diet (Straka Diet). Crickets and sugar water were used as a standard diet. After 6 weeks, fire ant colonies fed crickets and sugar water were healthy and had grown considerably. In contrast, colonies fed the artificial diets showed little or no growth demonstrating that these diets are not suitable for rearing healthy fire ant colonies. However, the Straka diet may be useful as a starting point for studies of basic fire ant nutritional requirements. We advise against formulating diets that mix sugar and protein into a single "all in one" diet because workers and brood have differing dietary requirements. This study is important because it warns other researchers that artificial diets are not yet suitable for rearing healthy fire ant colonies in the laboratory. The results of this study probably also apply to most other species of ants with generalist predator/scavenger diets.
Technical Abstract: Various artificial diets have been used for rearing imported fire ants; however most of these diets include insect supplements. This study was designed to examine growth of red imported fire ant colonies (Hymenoptera: Formicidae: Solenopsis invicta Buren) on four artificial diets: a chemically undefined “oligidic” predator diet, two partly defined “meridic” diets utilized by Bhatkar and Whitcomb (1970) and Dussutour and Simpson (2008) for Solenopsis fire ants and Rhytidoponera ants, respectively, and finally a completely chemically defined “holidic” diet utilized by Straka and Feldhaar (2007a; b Erratum) for carpenter ants. Crickets and sugar water were used as a standard diet. After 6 weeks, fire ant colonies fed crickets and sugar water were healthy and had grown considerably. In contrast, colonies fed the artificial diets showed little or no growth demonstrating that these diets are not suitable for rearing healthy fire ant colonies. Nevertheless, the holidic or entirely synthetic Straka diet may provide a suitable basis for further studies of fire ant dietary requirements because it resulted in modest production of all brood stages. We advise caution in using diets that mix sugar and protein into a single "all in one" diet because workers and brood have differing dietary requirements.