Butterflies primarily rely on nectar from flowering plants for fuel, but many species supplement their diet with other sugary liquids. Fruit provides an alternative source of sustenance, especially when nectar is scarce or when the butterfly requires additional nutrients. The attraction is highly selective, focusing on fruit in a particular state of ripeness to access the necessary components for energy and reproduction.
Preferred Fruit Selections
Butterflies strongly prefer fruits that are excessively ripe or have begun fermentation. Overripeness softens the fruit structure, making the juices accessible to the butterfly’s proboscis, the straw-like feeding tube used for feeding. Overripe bananas are consistently successful due to their high sugar content and soft texture.
Juicy, water-rich fruits are also attractive, including watermelon, cantaloupe, and sliced citrus fruits such as oranges. Other favored choices include soft, fallen fruits like plums, peaches, and heavily bruised apples, which should be left to soften and ferment slightly before being presented.
Biological Attraction to Decaying Fruit
The butterfly’s attraction to decaying fruit is driven by a need for specific nutrients often lacking in flower nectar. Nectar is primarily a source of carbohydrates for flight energy, but it lacks sufficient minerals and amino acids. Fermentation, initiated by yeasts and bacteria, breaks down the fruit’s complex components, releasing these supplementary substances.
Decaying fruit is rich in sodium, amino acids, and various salts required for metabolic functions and, particularly in males, for reproductive success. Some species, like the Red Admiral and Question Mark butterflies, depend heavily on tree sap and fermenting fruit, rather than flowers. Fermentation also produces trace amounts of alcohol, which attracts certain species seeking a caloric boost.
How to Serve Fruit to Butterflies
Presenting fruit effectively requires preparation to maximize juice exposure and placement to ensure accessibility. The fruit should be sliced or lightly mashed to break the skin and cell walls, allowing the butterfly to easily sip the exposed liquid through its proboscis. Placing the prepared fruit in a shallow dish or on a flat surface, such as a tree stump or a feeder platform, provides a stable landing area.
The best location for a fruit feeder is a sunny, warm spot sheltered from strong winds, as butterflies are cold-blooded and need warmth for feeding.
It is important to replace the fruit every two to three days, or whenever mold begins to form, to prevent the growth of unhealthy bacteria. To deter ants, place the dish on a stand with its base sitting in a small, water-filled saucer, creating a protective water barrier.