Skip to main content

#22: Caterpillars




Litinsects #22: Caterpillars

 Since you are freshly familiar with metamorphosis from my last posts, I will today be talking about caterpillars 🐛 and some structures that change drastically in appearance from before to after metamorphosis: legs.

Caterpillars are the worm-shaped larval stage of butterflies and moths. They have huge appetites; they mainly feed to grow and gain energy for their transformation into adulthood. In order to do this they need to get around, for which they use legs because only adult stages have wings. 

But insects only 3 pairs of legs, right? So where do all these extra legs come from all down the sides of their bodies? 

  • Caterpillars have 3 pairs of TRUE LEGS, attached to their thorax, which are jointed and have little claws on the end. These legs are still present after metamorphosis, though they will have changed substantially
  • Additionally, they usually have 2 to 5 pairs of PROLEGS, which are protrusions from the abdomen that caterpillars use to aid in movement and gripping surfaces. During metamorphosis these disappear, as they are an adaptation present only in the larval stage
Prolegs work sort of like Velcro. They have pads with tiny barbs on them that they use to attach to the surface they are walking on. Caterpillars don’t really use their prolegs to “walk”; instead they detach their suctioned prolegs, stretch their body forward, reattach their prolegs, and repeat. 

Prolegs also have sensory hairs so the caterpillar can feel what it is walking on. Since they only have simple eyes, this is the best way for caterpillars to sense obstacles in their paths.
Labels:

Comments

Post a Comment

Popular posts from this blog

#8: Butterfly Wings

Litinsects #8: Butterfly Wings Have you ever heard that you shouldn’t touch a butterfly’s wings or it will die? Well why is that...? Who remembers what I explained yesterday about Latin names? Butterflies and moths belong to the group LEPIDOPTERA, from the Greek words lepis for scale and pteron for wing. You probably guessed it already: butterfly wings are covered in SCALES! (Anyone starting to see a pattern with the names here? 😉 ) Butterfly scales are actually modified, flattened SETAE (aka hairs) that either partially or entirely cover the wings of most species. Some look like roof tiles, like on this here monarch, while some look more thread-like Scales protect and insulate the insect, but underneath the wing is actually transparent! Some species, like the GLASSWING BUTTERFLY, lack scales and have totally amazing see-through wings! Scales are responsible for the coloration of butterfly wings in one of two ways. First of all, scales contain...
Post a Comment
Read more

#58: Tardigrades

Litinsects #58: Tardigrades Anyone recognize these weird-looking little guys? They are actually not insects, as a matter of fact they are not even arthropods but they are cool enough to deserve a post. These are TARDIGRADES, also known as water bears or moss piglets. They are best known for their bizarre abilities to survive some of the most extreme conditions imaginable... © Science Faction Images -As always, the name’s etymology describes them a bit. It comes from the Latin “tardus” meaning “slow” and “gradior” for “step/walk”. Their common name comes from the fact that their walk looks a bit like a bear’s -Tardigrades are a PHYLUM of animals consisting of around 1,300 species. (Side note: the TAXONOMIC LEVEL of a group has nothing to do with how many species it contains. For example phylum Arthropoda, a taxonomically equivalent category consists of around 1 million described species and possibly millions more not yet described!). -These animals are all microscopic, ranging in ...
Post a Comment
Read more

#60: Cockroaches

Litinsects #60: Cockroaches Cockroaches belong to the order BLATTODEA, which is derived from the Greek word “blatta” meaning cockroach. Did you know that the Blattodea contains cockroaches AND termites? That’s right; termites are actually considered a specialized group of cockroaches! They used to be classified in an entirely different order of insects but recent genetic studies found a closer relation to cockroaches than previously thought. -Roaches are characterized by their broad, flat bodies. They have long antennae and generalized chewing mouthparts. In contrast to many other insects, which have 3, cockroaches have only 2 ocelli (or simple eyes) -Most people consider roaches to be disgusting, disease-spreading pests. But of 4,500 species, only 30 live in human habitats and are considered pests -The common name is derived from the Spanish word for the insect, “cucaracha” -Cockroaches can be found in a wide variety of habitats around the world. Many live in the tropics but...
Post a Comment
Read more