Conservation of the large blue butterfly (Phengaris arion): Distribution and density, oviposition preferences and relation to its host ant (Myrmica)
This thesis is led by Ambre Genard.
Background and Aims
The large blue butterfly (Phengaris arion) has experienced widespread decline across Europe, with Gotland serving as one of its remaining strongholds. Following the extreme drought of 2018, the population collapsed dramatically. Remarkably, the species has demonstrated impressive recovery in subsequent years. Its survival strategy appears linked to refugia in slightly more moist and shaded microhabitats. However, the precise relationships between its distribution, ground moisture levels, tree canopy cover, and the response of its host ant species to these environmental factors remain poorly understood.
The large blue butterfly has a unique lifecycle that relies on Myrmica ants. The larvae secrete a solution that attracts ants, tricking the ants into carrying them into their nests. The butterfly larvae then feed on the ant larvae and after pupating inside the nest, the adult butterflies emerge the following summer, completing their cycle. This complex interspecies interaction underscores the butterfly’s dependence on the presence and health of specific Myrmica ant populations. Consequently, conservation efforts targeting P. arion must also prioritize the protection and management of suitable Myrmica habitats to ensure the butterfly’s continued survival.
To ensure the long-term persistence of this unique butterfly, continued research and targeted conservation efforts are essential. My research aims to contribute to this knowledge by investigating key ecological factors influencing its distribution and habitat requirements.
Main Research Questions
How are the distributions of the large blue (Phengaris arion) and its host ant species (Myrmica) affected by different environmental gradients such as dryness, plants, and tree cover ?
How does the presence of the host ants affect the distribution and density of the large blue ?
Is the large blue actively using recently restored/ newly created areas ?
What are the oviposition preferences of the large blue ?
