By Hampshire & Isle of Wight Wildlife Trust
The Chalkhill Blue butterfly (Polyommatus coridon) is a striking and charismatic species that is native to the British Isles. With its vibrant blue wings and distinctive black edging, it is a common sight during the summer months in the chalk grasslands of southern England.
Chalkhill Blue butterflies are particularly fond of chalk grasslands, which are characterized by dry, thin soils and a diverse range of wildflowers. Chalk grasslands are home to a range of other rare and specialized species, including orchids, cowslips, and Adonis blue butterflies.
One of the best places to see Chalkhill Blue butterflies on the Isle of Wight is Arreton Down Nature Reserve. This reserve is managed by the Hampshire and Isle of Wight Wildlife Trust and is home to a large population of these stunning butterflies. Arreton Down is an important site for chalk grassland conservation. It supports a diverse array of chalk-loving plants and a range of wildlife, including skylarks, hares, and rare solitary bees.
The best time to see Chalkhill Blue butterflies is from mid-July to early September, when the adults emerge from their chrysalises and begin to fly. Clouds of this beautiful blue butterfly may be seen fluttering around low-growing flowers. During this time, the males can be seen patrolling their territories, which they defend fiercely against other males. The females are more elusive, spending much of their time resting on vegetation or laying their eggs on horseshoe vetch the sole food plant of their larvae.
Chalkhill Blue butterflies have an interesting relationship with ants. The larvae of the butterfly excrete a sugary substance known as honeydew, which is highly attractive to certain ants. In return for this sweet treat, the ants provide protection to the larvae, defending them against predators and parasites. This mutually beneficial relationship is known as myrmecophily and is found in many other species of butterflies and insects.
The Chalkhill Blue butterfly is a stunning and captivating species that is worth seeking out during the summer months. Be sure to stay on designated paths to avoid disrupting the grasslands where these butterflies reside. Additionally, please remember to clean up after your dog, as their poo negatively impacts the fragile soil ecology. By exploring these sites and gaining knowledge, we can all contribute to the conservation of these precious habitats.