Tuesday, April 16, 2013

The Dark Side of Butterflies (and Moths)

Butterflies are magical and wonderful!

And sometimes butterflies are pretty icky.

Not everything about butterflies is sweetness and light. Butterflies and moths can be pretty creepy in their habits, foods and defenses. Let's take a walk on the dark side of butterflies and moths and look at some of their more disturbing behaviors.

Vampire Moths
A Siberian species of moth in the genus Calyptra will drink blood from vertebrates, including humans. Check out the article here on National Geographic.

Flesh Eating Caterpillars

  • Snail Eating Caterpillar: The larvae of Hypomocoma molluscivora use silk to trap snails and then climb inside with the trapped gastropod so they can dine upon its slimy flesh. Who wouldn't appreciate escargot? More on Live Science.
  • Wasp Eating Caterpillar: The caterpillars of the species Euplthecla orlchloris also reside in Hawaii. These adorable inch worms can quickly snap their bodies to trap wasps which they then clutch tightly and slowly consume. More on this at on The Featured Creature. 

[DSCN0116%255B4%255D.jpg]
The adorable Flannel Moth caterpillar looks way less
cute after it stabs you with  toxic spines
and leaves you screaming.
Poisons A-plenty

  • Urticating hairs: Io moths have sharp, stinging hairs on their bodies called urticating hairs. Urticating hairs develop with each skin molt of the caterpillar. Each hair is a small hollow tube, sometimes with barbs, that is filled with an acrid fluid. These hairs are designed to break off the caterpillar body and lodge in a predator where the acrid fluid inside can enter the wound. The fluid can cause severe rash, irritation, swelling and allergic reactions to skin. More here on Io Moths.
  • Poison on the Inside: Monarch and Queen butterflies sequester poisons from the milkweed plant inside their bodies, creating a nasty surprise for predators who go in for a nibble. Pipevine swallowtails store aristolic acid inside their bodies which comes from the Pipevine (Aristolochia) plants that they eat. They are so noxious that many other species of butterflies will mimic them. Learn more here.
  • Osmeterium: Swallowtail caterpillars have a defense mechanism called osmeterium. Osmeterium are a fleshy organ where caterpillars of swallowtail species sequester essential oils from their host plants, also known as terpenes. These oils coat the normally hidden osmeterium which can be everted or pushed out when the caterpillar is threatened. More on Osmeterium here.

A Taste for Waste
Another icky food source for butterflies is waste. Urine and dung can contain salt and minerals that male butterflies especially need to replace salts and minerals they lose as part of their sperm package. Click through to this like to watch video of a Zebra Longwing butterfly happily feeding on fresh bird poop.


Eaters of the Dead
Butterflies can often be found puddling on the corpses of dead animals and fish. Once, while hiking in upstate NY I came across a beautiful group of Tiger Swallowtails all swarmed on some sort of mound. As I approached and the pile of butterflies was startled, so was I. The mound beneath them was a very large and very dead raccoon.

This slightly goofy video shows a group of several species of butterflies feeding on a dead fish. I can pick out Tiger Swallowtails, Spicebush Swallowtails and Red Spotted Purples. Yummy!

Drunkards and Wastrels
Butterflies in forested areas may not be able to find much in the way of nectar filled flowers for dinner, so they find lots of other things to eat. Rotting fruit is a favorite. As fruit rots, it ferments and creates alcohol. When butterflies sip upon this intoxicating nectar, they can become well and truly drunk. Butterflies have also been known to drink spilled beer. Consuming alcohol works the same on butterflies as it does on people. They lose their sense of balance, stagger about and are often unable to fly after imbibing.

Not So Very Consenting
Zebra Longwing butterfly males can be rather impatient when waiting for a new lady butterfly to come on the scene. When a female is still in chrysalis, males of this species can pick her out by pheromones and will flock to the chrysalis.

The males will compete for the best location and will mate with her either directly after she emerges from chrysalis (and is still unable to fly) or even sometimes break into the pupal case and mate with the female that is still in chrysalis. This behavior is sometimes referred to as 'pupal rape'

4 comments:

  1. I was so glad to see this post. I once observed a beautiful butterfly perched for quite some time on a pile of our dog's poo. It was kind of disturbing actually . . . didn't fit our mental image of "normal" butterfly activity!

    ReplyDelete
  2. Cool. I'm glad someone got to share my nature nerd video of the zebra longwing pupal rape.

    ReplyDelete
  3. You information about the distasteful-ness/poisonous-ness of monarchs is misinformation. Please correct...
    http://io9.com/the-experiment-that-required-scientists-to-eat-butterfl-509975995

    ReplyDelete
  4. While I was splicing fiber a butterfly landed on my hand that was holding a packet of alcoholic wipes. To my surprise, he starting drinking out of the open packet! I waited about a minute to see if he would die but he just flew up off without leaving a tip! Strangest thing I've seen.

    ReplyDelete

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