Skip to main content

#11: Woodlice

 

 Litinsects #11: Woodlice

Today we are taking a field trip outside of the insect world... You probably know them as pill bugs, roly-polys, or potato bugs but they have a ton of other regional common names. Woodlice are TERRESTRIAL ISOPODS and are actually a type of CRUSTACEAN! So these guys are more closely related to crabs and lobsters than to insects...

  • The ancestors of these creatures were marine isopods that COLONIZED LAND around 300 million years ago

  • Woodlice have flattened bodies and seven pairs of legs. They breathe through PLEOPODAL LUNGS, which are specialized appendages found on the back end of their bodies

  • These animals love dark and moist places because they lose water rapidly through their cuticle. You will often find them in small cracks or congregated against each other so that much of their bodies are in contact with another surface. This is known as positive THIGMOKINESIS, which is the term for when organisms reduce their locomotor activity while in contact with a surface (as opposed to negative thigmokinesis). This serves to reduce water loss in woodlice

  • They shed their exoskeleton in two stages, first the back half and a few days later the front half (and then often feed on their old skin). Most other arthropods molt in one continuous process  

  • Woodlice are generally not considered pests; they are detritivores that feed on dead plant matter

  • Female woodlice carry their fertilized eggs in a MARSUPIUM underneath their bodies and can appear to give birth to their young that look like tiny whitish versions of the adults (see second picture). Some species even display maternal care

 
< https://commons.wikimedia.org/wiki/File:A_female_woodlouse_with_offspring.jpg > ©Patrick Niemeyer

Labels:

Comments

Post a Comment

Popular posts from this blog

#13: Insect Legs

Litinsects #13: Insect Legs Insect legs can be as diverse as the animals themselves. Some are long and slender like a crane fly’s, some are short and hefty like a mole cricket’s. But what all insects share is the number and layout of those legs. Hexapods have 6 LEGS, a pair each of fore, mid, and hind legs that are made up of the same basic units. Starting closest to the body, they are:  (1) the coxa, which attaches the leg to the thorax  (2) the trochanter (3) the femur, which is oft en the thickest segment  (4) the tibia, often covered in tiny hairs (5) the tarsus, which contains 5 “pseudo-segments”  (6) the pretarsal claws, of which most insects have 2 on each leg The basic units of the leg always occur in this order but may be reduced or highly modified in some species to fit certain tasks such as running, digging, swimming, grasping, or jumping. This photo sums it up perfectly: from < https://wiki.bugwood.org/File:Insect...
Post a Comment
Read more

#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 le gs 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 fr...
Post a Comment
Read more

#4: Simple Eyes

Litinsects #4: Simple Eyes Yesterday I talked about compound eyes, the multi-faceted structures that most insects use to see the world 👀 But insects actually have another visual system as well, composed of simple eyes or OCELLI. Unlike compound eyes, ocelli are composed of only one structure which makes them comparatively “simple” although they are still very important. These are light-detecting organs consisting of a single lens with sensory cells. They can detect movement but don’t form complex images. “Ocellus” comes from the Latin word oculus, meaning eye. So these structures are literally “little eyes” Ocelli are located on the insect’s head, usually between or adjacent to the compound eyes. They are usually dome-shaped, somewhat shiny structures In most flying insects (such as flies, dragonflies, bees, etc.) there tend to be three ocelli in a triangle arrangement (see photo). Some terrestrial insects (like cockroaches) have only two ocelli ...
Post a Comment
Read more