Dump size and distance from the nest define the investment in waste management in Sericomyrmex mayri (Formicidae: Myrmicinae: Attini)

Abstract

The farming system practiced by non-leaf-cutting ants Sericomyrmex mayri (Formicidae: Myrmicinae: Attini) involves a mutualistic interaction with symbiotic fungi. Their colonies’ success depends on several factors, such as the fungus garden protection against pathogens. Garden contamination may depend on the aspects involved in waste management. However, specific local conditions, including nest and dump sizes, nest-dump distances and abiotic conditions are relevant and overlooked, especially for non-leaf-cutting ants. We aimed to explore the natural history involved in Sericomyrmex mayri waste management. Hence, we documented the relationships between 1) the foraging rate and waste removal activities with dump size, 2) the size of refuse dumps and their distance from nest entrances, and 3) the foraging activity and the rate of waste disposal with climatic conditions. The study was developed in the Atlantic Forest, Southeastern Brazil, wherein 33 colonies’ activities were monitored for three consecutive days, during different day-periods. More prominent dumps received less waste and were located at further distances from the nest. Additionally, daily temperature and humidity positively influenced waste disposal and foraging activities, respectively. These findings provide information on how dump size and distance from the nest may define the investment of waste management of non-leaf-cutting ants.

Keywords

• fungus garden
• mutualism
• fungus-growing ants