A moisture differential technique: a new method for the separation and maintenance of the imported fire ant colonies in the laboratory

Authors: SHAH, FARHAN - University Of Mississippi; KHAN, IKHLAS - University Of Mississippi; ALI, ABBAS - University Of Mississippi

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2025
Publication Date: 1/30/2025
Citation: Shah, F.M., Khan, I.A., Ali, A. 2025. A moisture differential technique: a new method for the separation and maintenance of the imported fire ant colonies in the laboratory. Scientific Reports. 30,15:3742. https://doi.org/10.1038/s41598-025-88116-y.
DOI: https://doi.org/10.1038/s41598-025-88116-y

Interpretive Summary: Imported fire ants invade agriculture, urban, and natural habitats and are considered major public health pests resulting in an annual loss of $6.7 billion. Rearing and maintaining laboratory colonies are crucial for fire ant research. Many methods including water dripping method are used to separate the ants from the mound materials. The water dripping method that is based on rafting behavior of fire ants can quickly separate fire ants from shoveled mound soil under laboratory conditions. This method, however, results in a significant loss of brood while worker recovery is very variable. In this study we proposed a new method, called moisture differential technique, which effectively separates the ants from mound materials with minimum losses of workers, reproductives, and the brood. The moisture differential method can collect 52% more colony mass as compared to conventional water dripping method. Researchers can successfully use this new technique to separate ants with minimal colony losses and without effecting their normal digging behavior. Stress free workers with normal digging behavior are extremely important in sand digging repellent bioassays. This technique also allows colonies to develop in small containers that are filled with soil for experimental usages.

Technical Abstract: Imported fire ants invade agriculture, urban, and natural habitats and are considered major public health pests resulting in an annual loss of $6.7 billion. Rearing and maintaining laboratory colonies are crucial for fire ant research. Many methods including water dripping method are used to separate the ants from the mound materials. The water dripping method that is based on rafting behavior of fire ants can quickly separate fire ants from shoveled mound soil under laboratory conditions. This method, however, results in a significant loss of brood while worker recovery is very variable. In this study we proposed a new method, called moisture differential technique, which effectively separates the ants from mound materials with minimum losses of workers, reproductives, and the brood. The moisture differential method can collect 52% more colony mass as compared to conventional water dripping method. Researchers can successfully use this new technique to separate ants with minimal colony losses and without effecting their normal digging behavior. Stress free workers with normal digging behavior are extremely important in sand digging repellent bioassays. This technique also allows colonies to develop in small containers that are filled with soil for experimental usages.