Adult butterflies need energy and use their proboscis to drink sweet nectar from flowers with a high sugar content. They are restricted to a liquid diet.
Daily water uptake is also essential to prevent desication.
Butterflies search for liquid rich fluids for their own consumption and for places where the larval food-plants, rich in protein, are growing.
Butterflies will be feeding in the habitat where the larval foodplants grow and also feed in other habitats for mate location, roosting and protection.
Butterflies - nectar plants but not only!
Nectar is the mains source for all adult butterflies (Fig. 1a-b). The sugars give them the energy needed to move around, to mate and to lay eggs.
They are attracted by all kinds of nectar-producing plants and will help to pollinate these plants as they move around. Butterflies are important pollinators.
The length of the proboscis will determine which flowers are suitable. Some Hesperiidae have a proboscis that is longer than the body length and others, like some Theclinae (Hairstreaks), only have short ones and use honeydew as main food source.
Butterflies are also foraging for food from other sources:
- Rotten fruit: drinking the liquid from rotten fruit fallen from a tree.
- Tree sap: drinking on tree trunks.
- Mud puddles, wet gravel: gathering salt and minerals needed for the butterfly's nutrition. Sometimes large groups can be seen feeding togheter.
This behavior is called mud-pudldling (Fig. 2a).
- Ditches: drinking liquids.
- Drying excrements: drinking liquid and gathering minerals (Fig. 2b)
- Sweat: gathering salts (Fig. 2c)
- Small corpses: gathering proteins, minerals and drinking liquids.
Some butterflies, especially migrators and species that overwinter in the adult stage, can gather food in fat cells.
Caterpillars - hostplant(s)but not only!
Caterpillars need protein-rich food to grow and feed on different parts (leaves, buds, seeds and fruits) and on a variety of plants (Fig. 3a-b)
The quality of the food varies during the course of the seasons. Theclinae which hatch before bud burst have very young leaves of high food quality. Caterpillars of these species hatching later will die because the first instar caterpillar is not able to eat mature leaves.
Monophagous caterpillars are feeding exclusively on one hostplant (Fig. 4). It is estimated that 20 % of the European species are monophagous.
Oligophagous caterpillars often feed on small, related group of plants. This is half of the European species.
Polyphagous caterpillars are generalist feeders eating a large variety of plants and accounts for 30 % of the European species.
Most plant families are used and a few plant families are favoured: Fabaceae and Poaceae.
Most plant species are only utilised by a few species. Festuca is favoured by a large number of grass-eating caterpillars.
Depending on the season, the site and the geography different hostplants can be preferred. This complex interplay of factors must be taken into account for the conservation of butterflies and for nature management.
Many Lycaenidae and Riodinidae form relationships with ants, myrmecophily, that provides protection to the caterpillars. For some Phengaris, the safety and food security of the ant nest is attractive. The caterpillars are fully dependent on care by ants. They possess organs to seduce the ants and secrete a substance that exactly matches that of ant larvae. The worker ants accept, protect and feed the caterpillars with ant larvae and eggs but also with prey from the ants.
Useful link
(url) Clarke H. 2024. A checklist of European butterfly larval foodplants. — Ecology and evolution 14, e10834.
(url) Clarke H. 2022. A provisional checklist of European butterfly larval foodplant. — Nota Lepidopterologica45: 139-167.
(url) Bink F. & Moenen R. 2015. Butterflies in the Benelux. Based on Dagvlinders in de Benelux. Revised and exetended. General Chapters 11. Search for food.
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