# Holly Blue (*Celastrina argiolus*) The Holly Blue is a small, beautiful butterfly with bright blue wings. It loves to flutter around gardens and woodlands, bringing joy to everyone who sees it. - **Category:** [Insects](https://www.snappit.app/explore/categories/insect) - **Rarity:** Common - **Danger:** 1/5 · Very low - **Snaps:** 1 - **Habitat:** Woodlands - **Also known as:** Holly Butterfly ![Holly Blue](https://commons.wikimedia.org/w/index.php?title=Special:Redirect/file/Holly_blue_%28Celastrina_argiolus%29_male.jpg&width=800) Photo: Charles J. Sharp, CC BY-SA 4.0 · [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Holly_blue_%28Celastrina_argiolus%29_male.jpg) ## Appearance The Holly Blue is a small, vibrant butterfly. Males boast brilliant sky-blue upper wings, while females have similar blue wings with distinct broad black borders on their forewings. Both sexes feature pale silvery-blue or white underwings, usually unmarked or with very tiny, sparse black dots, which helps distinguish them. ## Taxonomy - **Kingdom:** Animalia - **Phylum:** Arthropoda - **Class:** Insecta - **Order:** Lepidoptera - **Family:** Lycaenidae - **Genus:** Celastrina ## Interesting facts - Holly Blues overwinter as pupae, hidden away until spring arrives! - Its caterpillars start by eating flower buds, then switch to fruits as they grow! - The first generation's caterpillars often feast on holly, while the second prefers ivy! - These butterflies can have two or even three generations born in a single year! ## Special abilities - **Disguise Underwings:** Holly Blue has pale, unmarked underwings that help them blend against the sky, making them harder for predators to spot. - **Bud Biter:** Holly Blue can lay eggs directly inside flower buds, providing immediate shelter and food for their caterpillars when they hatch. - **Ant Alliance:** Holly Blue caterpillars have special glands that secrete sugary fluid, attracting ants that protect them from predators. ## Measurements & details - **Wingspan:** 26-34 mm - **Size:** 10-15 mm - **Lifespan:** 7-21 days - **Leg Count:** 6 ## Diet & Feeding Caterpillars munch on plant buds and fruits, while adult butterflies sip on flower nectar. - **Age differences:** Caterpillars eat flower buds and fruits; adults feed on nectar from flowers. - **Primary Foods:** Flower buds, Young fruits, Nectar, Honeydew, Holly flowers, Ivy flowers - **Foraging Method:** Foraging ## Ecological connections - **Eats:** Common Holly (*Ilex aquifolium*) — Caterpillars often feed on holly buds. - **Eats:** Common Ivy (*Hedera helix*) — Later generations of caterpillars prefer ivy. - **Symbiotic with:** [Black Garden Ant](https://www.snappit.app/explore/black-garden-ant) (*Lasius niger*) — Ants protect caterpillars for honeydew. - **Eaten by:** [Great Tit](https://www.snappit.app/explore/great-tit) (*Parus major*) — Adults and caterpillars are prey for birds. - **Pollinates:** [Dandelion](https://www.snappit.app/explore/dandelion) (*Taraxacum officinale*) — Adults visit flowers for nectar, aiding pollination. ## Traits - [Solitary](https://www.snappit.app/explore/traits/solitary): Solitary animals live alone for most of their lives, only interacting with others for mating or parental care. - [Colorful](https://www.snappit.app/explore/traits/colorful): Colorful describes organisms or objects displaying a wide range of bright and distinct colors. - [Herbivorous](https://www.snappit.app/explore/traits/herbivorous): This trait characterizes organisms whose diet consists entirely or primarily of plant material. - [Pollinator Magnet](https://www.snappit.app/explore/traits/pollinator-magnet): Describes plants that are particularly attractive and beneficial to a wide range of pollinating organisms. - [Forest](https://www.snappit.app/explore/traits/forest): Forest habitats are terrestrial environments dominated by dense tree cover, supporting a high diversity of plant and animal life. - [Diurnal](https://www.snappit.app/explore/traits/diurnal): Diurnal animals are primarily active during daylight hours, typically resting or sleeping at night. - [Pollinator](https://www.snappit.app/explore/traits/pollinator): Describes organisms that transfer pollen, enabling the fertilization and reproduction of plants. ## Collections - [Insects](https://www.snappit.app/explore/collections/insects) ## Safety **Danger:** 1/5 · Very low Butterflies are safe to watch, but it's best to look without touching them. ## Frequently Asked Questions ### How to identify Holly Blue? Compare the wing outline, spots, bands, eyespots and wing edges. The underside can look completely different from the top. Check for tails, the antennae and where the markings sit instead of relying on color alone. Butterfly Identifier: upload a photo and compare the visible details. ### What is Holly Blue's wingspan? 26-34 mm ### How big is Holly Blue? 10-15 mm ### How long does Holly Blue live? 7-21 days ### What does Holly Blue eat? Caterpillars munch on plant buds and fruits, while adult butterflies sip on flower nectar. ### Where is Holly Blue usually found? Woodlands ### How does Holly Blue hunt? Foraging ### How many legs does Holly Blue have? 6 ## Where to spot - [Skandinavisk Dyrepark](https://www.snappit.app/guides/places/skandinavisk-dyrepark) — Central Denmark Region, DK · Zoo ## More Insects - [Common Eastern Bumble Bee](https://www.snappit.app/explore/common-eastern-bumble-bee) (*Bombus impatiens*) - [Spotted Lanternfly](https://www.snappit.app/explore/spotted-lanternfly) (*Lycorma delicatula*) - [Brown-belted Bumble Bee](https://www.snappit.app/explore/brown-belted-bumble-bee) (*Bombus griseocollis*) - [Eastern Carpenter Bee](https://www.snappit.app/explore/eastern-carpenter-bee) (*Xylocopa virginica*) --- Source: [Holly Blue: Characteristics, Facts & Places to See — Snappit](https://www.snappit.app/explore/holly-blue)