[2] Although it was initially classified as a subspecies of P. alcon, a European researcher, Lucien A. Berger, designated it as a separate species in 1946.

Genetic similarities between P. rebeli and P. alcon have led many researchers to argue that the two are the same species and differences are due to intraspecific variation.

[2] Although P. rebeli is found across the Palearctic (see subspecies), it is difficult to determine the species' precise range due to confusion with P.

[4] P. rebeli is dependent on the plant Gentiana cruciata early in its life cycle[5] and is vulnerable to parasitism by Ichneumon eumerus while inside the nest of M.

Another way these groups are categorized is by whether or not they release a chemical (dorsal nectary organ secretions) to attract the attention of the host ant.

[11] The undersides of the wings are a dark brown with small black spots that are circled in white.

[11] This butterfly begins life as eggs laid on leaves of Gentiana cruciata plants.

P. rebeli choose where to lay their eggs based on the size of G. cruciata leaves and not upon the location of the closest Myrmica ant colony.

[14] Larger populations of G. cruciata are associated with higher production of flowers and seeds, but also with an increased frequency of P. rebeli feeding upon the plant.

[16] While Myrmica ant colony members can identify each other through chemical signaling, social ranks are partially determined by sound acoustics.

[18] The most common functions of the queen ant sounds are to recruit workers, smell nestmates, and facilitate oral exchanges of food and pheromones.

[18] Most importantly, however, is the fact that distress noises made by the queen causes workers to raise their guard and bolster her protection.

[21] This phenomenon is seen during times of stress, when some of the hungry P. rebeli caterpillars secrete compounds to attract attention from the ant colony it has parasitized.

[22] Thus, in periods of starvation, P. rebeli caterpillars overall exhibit a higher survival rate than those of the M. schencki larvae.

After the ant brood adopts the FDL, which comprise approximately 25% of the total P. rebeli larvae,[23] the FDL complete growth the following spring and eclose (emerge as an adult from the pupa) in early summer to complete their life cycle.

[24] While both larva types ultimately form similar-sized pupae, their polymorphic growth rates could indicate alternative fitness strategies and different ways to exploit the M. schencki's food resources.

[25] Scientists hypothesize that this plasticity is due to warm conditions and more light exposure, which affects larval development.

[25] This has led researchers to speculate that P. rebeli larvae that do not receive adequate food can still fully develop in one year and act as a functioning adult.

This hypothesis is supported by the fact that certain researchers claim that P. rebeli larvae can have continuous development.

[6] It is able to enter the nest without being swarmed by releasing a chemical which causes the worker ants to attack one another instead of concentrating their efforts on the wasp.

[6] P. rebeli has been rigorously studied in Europe because it has priority conservation status and was classified as "vulnerable" in 2000 by the IUCN Red List of Threatened Species.

The causes of this drastic population reduction are thought to be agricultural land use changes, abandonment of extensive management, and deforestation.