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#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

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