Moths and butterflies (lepidopterans) are the second largest order of insects, comprised of almost 160,000 species (Monaenkova et al, 2011) and their feeding habits are as diverse as they are. Most of them feed on the nectar found in flowers, some even feed on the pollen, but they have so many more weird and wonderful ways of obtaining the nutrients they need to survive.
Before we start, let me just clarify that this post deals with adult lepidopterans the butterflies and moths, not the caterpillars. Caterpillars can differ greatly in their diet compared to the adults, and that would be a whole other post. So apart from visiting flowers what else do moths and butterflies eat?
Fruit and Sap
Some lepidopterans feed on tree sap, fruit or rotting fruit. Moths, such as the aptly named fruit-piercing moths, use their proboscises to penetrate fruit to suck out the juice. Visits by fruit piercing moths can be disastrous for farmers as the holes created allow bacteria and fungi into the fruit which causes them to rot and fall off the tree (pestnet, n.d.)
Lepidopterans cannot live of fruit or flowers alone they need other nutrients to survive, and this is where there feeding habits become truly bizarre..
You may have noticed, if you’ve visited one of Thailand’s numerous stunning national parks or wild areas, that you often see groups of butterflies aggregating around puddles or areas of wet soil; a behaviour known as mud puddling, or just puddling. Naturally, you’d assume they were using those delicate straw like proboscises to suck up water, but this is not the case…
If you watch a butterfly puddling for a while you might notice it excreting water as it does, sometimes quite forcibly as can be seen below. This would suggest that “substances dissolved in water, rather than water itself, are the principal resource accumulated through puddling” (Beck, J., Mühlenberg, E. and Fiedler, K. 1998).
So why are butterflies and moths visiting puddles if they’re not after water? Well, they’re after the nutrients dissolved in the water, particularly the salt. This is due to the fact that most terrestrial plants aren’t a great source of salt, which means that most terrestrial herbivores must find another source of the precious mineral. For butterflies, that could be a patch of moist ground, a rotting carcass, tears, excrement, sweat, or in some cases even blood (Beck, J., Mühlenberg, E. and Fiedler, K. 1998).
The puddling behaviour of butteflies goes way beyond just wet patches of land and into the realms of the truly bizarre…
Some moths which normally pierce fruit, have been known to use their proboscises to drink blood when the opportunity presents itself, and yes, you guessed it, they’re called ‘Vampire moths’ (Entomology Today, 2015).
Some Lepidopterans have been observed drinking tears (Lachryphagy) from crocodiles, turtles, elephants and birds. There are more than 100 species known to do this, 23 of which have been observed feeding on human tears (Plotkin and Goddard, 2013, pp.289-290).
Some lepidopterans have been known to drink sweat (Sudophagy) and you may notice a butterfly or two land on your backpack or shirt if you take it off after a long day of trekking.
As you’re probably starting to realise by now, butterflies really aren’t that bothered by where they puddle, and even rotting carcasses aren’t off limits to some species.
Yup, butterflies love a good bit of poo to suck on too. As Naturalist and butterfly expert Andre Coetze remarks, “for anyone with an interest in butterflies, smelly mud and stinky excretions often lead to the best shots…” (Coetzer, 2014). A sentiment I agree with wholeheartedly. When butterflies congregate around a nice wet patch, rotting fruit or dung, they often stay still longer than they usually would, allowing you to get some great photos.
Usually, you still have to employ a little stealth when photographing puddling butterflies, but sometimes they are so preoccupied that you can get really close to them, really close. The Tawny Rajah (Charaxes bernadus) below was so focused on the dropping it had found, that I was able to gently coax it onto my hand for a closer look.
I hope this post was interesting and that you learnt something new as I did when I set out to find out more about lepidopteran feeding habits. Below is a gallery of some of the photos I’ve taken of lepidopterans feeding:
Beck, J., Mühlenberg, E. and Fiedler, K. (1998)Mud-puddling behavior in tropical butterfies: in search of proteins or minerals? Oecologia. Vol.119, pp.140-148
Coetzer, A. (2014) Mud-puddling … the butterfly’s dirty little secret. Available: https://www.earthtouchnews.com/in-the-field/backyard-wildlife/mud-puddling-the-butterflys-dirty-little-secret/
Entomology Today (2015) Vampire Moths Suck the Blood of Vertebrates, Including Humans. Available: https://entomologytoday.org/2015/10/30/vampire-moths-suck-the-blood-of-vertebrates-including-humans/
Jackson, G. (n.d.) Pacific Pests and Pathogens – Facts Sheets – Citrus fruit piercing moth. Available: http://www.pestnet.org/fact_sheets/v6/citrus_fruit_piercing_moth_113.htm
Monaenkova et al (2011) Butterfly proboscis: combining a drinking straw with a nanosponge facilitated diversification of feeding habits. J. R. Soc. Interface. 2012,9. pp.720-726
Plotkin, D. and Goddard, J. (2013) Blood, sweat, and tears: a review of the hematophagous, sudophagous, and lachryphagous Lepidoptera. Journal of Vector Ecology. Vol.8,2 pp.289-294