Butterflies lay their eggs on the leaves of specific host plants. When the eggs hatch, the caterpillars will first eat the eggshell after which they will chew up the leaves. Each species of butterfly will have its specific host plant or plants. And if the eggs are placed on the wrong host plant, the caterpillars will die from starvation.
Unlike caterpillars with their chewing mouthparts, butterflies only have a proboscis – paired tubes that function like a drinking straw LINK 1 and LINK 2. This limits butterflies to a liquid diet, like the Yellow Glassy Tiger (Parantica aspasia aspasia) above feeding on flower nectar. But this does not mean that all butterflies feed on flower nectar.
Many forest butterflies feed on the moisture found amongst the rotting leaf litter. This moisture may come from the decomposing organic matter or the fermenting fruits found on the forest floor.
Some like the Malay Viscount (Tanaecia pelea pelea) feeds on the spore slime of the basket stinkhorn (Dictyophora indusiata) LINK while others feed on carrion, fruit juice, excrement or the sugary secretions of homopteran insects.
The above video clip shows a Common Faun (Faunis canens arcesilas) feeding on a rotting fig. The slender proboscis can be seen dipping repeatedly into the exposed fruit as the butterfly sips the liquid. The juice from the rotting fruit provides sugars and their alcohol derivatives. This alcohol can render the butterflies drunk, causing them to remain still as they continue feeding, making them vulnerable to predators. Birds similarly become drunk after feeding on rotting fruits LINK.
Butterflies also feed on sugars secreted by plants like the young shoots of Leea indica, competing with ants. They also feed on the sugary secretions of homopteras like melaybugs, aphids and coccids that usually coexist with ants. The above image shows a Bigg’s Brownie (Miletus biggsii biggsii) feeding on sugary secretions secreted by coccids.
Butterflies also indulge in what is commonly known as puddling LINK. The above video clip shows the Common Rose (Pachliopta aristolochiae) puddling. This involves taking liquid from wet and damp soil as well as puddles contaminated with urine and excrement for nutrient like sodium and amino acids. To obtain the necessary amount of nutrients, the butterflies have to take in large quantities of liquid. And if you are to observe these butterflies puddling, you may see them ejecting the excess liquid out through their anus.
In urine there is sodium and ammonium ions while dung (also bird droppings) and carrion provide ammonium rather than sodium. The image above shows a Green Commodore (Sumalia daraxa) feeding on a dead lizard while below a Paintbrush Swift (Baoris oceia) feeds on bird droppings.
Only males indulge in puddling. The nutrients taken in are later passed on to the females during mating as a nuptial gift. It is claimed that such nutrients enhance the survival rate of the eggs.
Note: Images are by Khew Sin Khoon and videos by KC Tsang.