Colony Growth of Two Species of Solenopsis Fire Ants (hymenoptera: Formicidae) Reared with Crickets and Beef Liver

Most diets for rearing fire ants and other ants contain insects such as crickets or mealworms. Unfortunately, insect diets are expensive, especially for large rearing operations, and are not always easily available or uniformly effective. This study was designed to examine colony growth of Solenopsis (Hymenoptera: Formicidae) fire ants fed beef liver. Five experiments were performed: four with Solenopsis invicta Buren colonies and one with Solenopsis geminata (F.) colonies. In these experiments, we compared the net growth of colonies fed raw liver, boiled liver-agar, and/or raw liver-agar all with house crickets (Acheta domesticus, (L.); Orthoptera: Gryllidae) as a standard diet. Both liver and house cricket diets produced healthy growing colonies at the end of 6-8 wk. However, colonies fed crickets were 1.7 to 3 times larger than those fed with liver. Raw liver and raw liver-agar diets performed similarly. Boiling the liver significantly reduced colony growth in S. geminata, but liver boiled for as long as 45 min still produced healthy fire ant colonies. This study demonstrates that beef liver is an acceptable diet for rearing laboratory colonies of both S. invicta and S. geminata for periods up to 6 months when maximum growth rates are not needed. However, house crickets are recommended for research studies where maximal growth is important because liver, mealworms, and banded crickets (Gryllodes sigillatus, F. Walker; Orthoptera: Gryllidae) are not as effective. Poor survival of liver-fed colonies after 8 months may indicate that beef liver is not an acceptable long-term diet. Pilot tests with canned liver cat food and a dry dog food showed they were palatable but not suitable for brood production in fire ant colonies.