The
#slaveant #Formica #fusca (
#Formicinae): about its general
#biology, their
#longlived #queens and
#workers and the role of
#individualism in a colony.
Formica rufa is a widespread and common ant species in Europe. Its
#colonies are often
#polygynous, meaning that several active queens live in one
#nest. The nests are built underground. The species is often used by other ant species to found their colonies. Sometimes also pupae are stolen by ant species and young workers are subsequently forced to work in the predating ant's colony. That's why the species is named slave ant.
As with many other ant species, various
#myrmecophilous species, such as
#mites, nematodes, or specially adapted insect species, live in the nest of Formica fusca.
An interesting biological peculiarity that can generally be found in ants is the unusually long
#lifespan of the queens, and sometimes also of the workers, related to other insects. The queens of Formica fusca can live for over 15 years, but the workers also reach an age of more than eight years.
This is unusual, because insects are known for their short lifespans, at least as adults.
In general, very small animals tend to have a shorter life expectancy because their
#bodysurface area is rather large relative to their body volume. This means that heat
#energy is more easily dissipated to the outside, which is why these animals suffer from a constant lack of energy and die more quickly from exhaustion. The difference is clearly visible when comparing shrews and elephants. Insects often have more effective protection against evaporation than shrews, namely in the form of their chitinous cuticle. However, the fact that completing their life cycle, especially mating, egg laying, and possibly brood care, consumes so much additional
#lifeenergy that the protective effect of the chitinous cuticle is insufficient in the long run.
But why do queen ants, like those in Formica fusca, live so long? Well, one reason for this is that they can concentrate fully on egg production and don't have to waste any further energy.
But why then do the workers of Formica fusca also live so long?
This is seemingly due to the fact that the workers are quite large compared to other native ant species. But also, because Formica fusca is relatively insensitive to rapidly changing
#environmentalfactors. Furthermore, the individual demands on each worker and their
#workperformance appear to be lower than in other ant species. However there must also be factors at the molecular genetic level that slow down the aging processes.
In their review, the authors D. E.L. Promislow al. (2022) provide an overview of external and molecular genetic factors of life expectancy in insects. Starting with information on aging in the very well-researched
#dipteran species Drosophila melanigaster, they also include research results on other insect species, discussing the various aspects that influence life expectancy in insects in much more detail than is possible my short
#article.
Ants are often viewed more as functioning machines than as
#sociallyorganized individuals. But this is incorrect. Individual behavior, such as
#laziness or
#diligence, has rather long been known in ants.
The authors C. Carere et al. (2018) scientifically examined the topic of "Individual
#behavioraltype and
#groupperformance in Formica fusca ants." In their study, they established the connection between individual behavior and group performance using experimental approaches. Worker groups were separated based on their similar individual behavior tendencies and their behavior related to the transport of offspring cocoons was documented.
©
#StefanFWirth,
#Berlin August 2025
References:
D. E.L.Promislow al. (2022) :
doi.org/10.1146/annurev-ento…
C. Carere et al. (2018):
doi.org/10.1016/j.beproc.201…
#Photos:
F. fudca workers on common
#tansy guarding
#aphids of
#Metopeurum #fuscoviride on a dry
#meadow nearby urban
#park Goethepark in Berlin © S.F. Wirth, 2025