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The Differences Between a Butterfly & a Stick Insect

Few could mistake a stick insect for a butterfly. Stick insects look like twigs and occasionally leaves. It's mostly the caterpillars of some butterflies who use such camouflage, though the leaf butterfly does resemble a dead leaf when at rest. Some stick insects have wings but don't like to fly while butterflies are usually strong flyers. Besides the fact that they're insects and found all over the world, there are many differences between butterflies and stick insects.

Body
- Besides being mimics of twigs and leaves, stick insects have a large degree of sexual dimorphism, which means that the males and females are quite different. The males are smaller and more slender than the females. In butterflies, sexual dimorphism is less drastic. Stick insects may or may not have wings, while the wings of butterflies can have beautiful colors and patterns. Butterflies are strong fliers as they travel from flower to flower and other food sources. Stick insects are amongst the longest and heaviest of insects. Females of heteropteryx dilatata can weigh more than 2.3 oz. The Queen Alexandra's birdwing is the largest butterfly in the world, with a wingspan of 11 inches, but at .4 oz. nowhere near as heavy.
Reproduction
- The eggs of walking sticks sometimes resemble seeds and can be scattered or glued to leaves or other surfaces. Butterflies also sometimes scatter their eggs, or lay them carefully in rings or clusters on plants. Walking sticks engage commonly in parthenogenesis, which means the males have nothing to do with reproduction. Butterfly reproduction is sexual. Walking sticks also undergo incomplete metamorphosis which means that the juveniles that hatch from the eggs look somewhat like miniature adults and molt until they're mature, which might take years in some species. Butterflies undergo complete metamorphosis. Their eggs hatch into caterpillars that eat, pupate and emerge from the pupae as adult butterflies.
Defense
- The walking stick's greatest defense is its resemblance to a twig or leaf. When a predator is nearby it will stay still. If that doesn't work it might spray the predator with a noxious fluid. Some can make a hissing sound with their wings or scratch attackers with the spines on their legs. Others use their wings to flash at and startle predators. Some play dead. Some butterflies have eyespots on their wings that make their would-be predators believe they're larger and more dangerous than they are, or that the eyes belong to snakes or other dangerous animals. Others display colors that warn predators that they're poisonous.
Diet
- Stick insects eat the leaves of their food plant, sometimes to the point of defoliation. Some eat a variety of leaves and some stick to leaves of the rose family or the eucalyptus. Butterflies siphon nectar and other fluids through a proboscis. Their caterpillars can be voracious, however.

Insects & Science