Tuesday, May 7, 2013

Lepidoptera Vocabulary Lesson III: Getting Technical

Our husbandry lab is a pretty informal place, and so are the people who work there. We usually don't worry too much about using the formal scientific terms, but there are a few we toss around on a regular basis that might be confusing to those outside the field of lepidoptery. Here are some of the terms we do use, along with their less formal counterparts.

Oviposit = Lay Eggs
When female butterflies or moths deposit eggs on leaves of host plants, the process is called ovipositing, literally "depositing eggs". While this term could apply to any organism that lays eggs, it tends to be used mainly for insects, as they have an actual body part called an ovipositor. Learn more about ovipositing here.
  • "If you look closely at this Great Southern White butterfly, you can see her bend her abdomen up to the plant and oviposit her eggs one by one."
Great Southern White ovipositing on peppergrass
Larva = Caterpillar 
Many species of insects have a larval form, which is basically a juvenile form that is distinct and different from the adult form. Butterfly and moth larvae are both called caterpillars. (Plural: larvae)
  • "In the BioWorks lab, we keep our larvae in tanks separated by species, where we supply them with the host plants they eat."

Molt = Shed Skin
Insects have exoskeletons instead of bones. Exoskeletons cannot grow, so when insects get larger, they must leave their old exoskeletons behind and form new ones, in a process called molting. In a caterpillar, the exoskeleton is called the "skin", and it must be shed as the caterpillar grows.

  • "This caterpillar is molting, leaving the old skin behind. The new skin underneath has some extra room to expand as the caterpillar eats, but it will eventually be shed as well."

The small white line below this sulphur caterpillar is the skin it has just molted.

Instar = Stage 
Instar is the word used to describe a stage between molts in insect larvae. Most butterfly and moth caterpillars have five instars. Often the instars differ only in size, but in some species, the various instars look completely different. Learn more about instars here.
  • "In their first instar, Giant Swallowtail larvae and Eastern Black Swallowtail larvae look similar, but by the third instar, they are very different and easy to tell apart."
Second instar (top) and fifth instar Black Swallowtail caterpillar
Frass = Poo
Without mincing words, let's just say that caterpillars produce a lot of poo, waste, excrement, etc. The technical term for this is frass, which rhymes with "brass". Learn more about frass here.

  • "We clean the frass out of the caterpillar tanks daily, to avoid the mold and disease that can affect caterpillar health."

Yup, that's a lot of frass.


No comments:

Post a Comment

We welcome your participation! Please note that while lively discussion and strong opinions are encouraged, the MOSI BioWorks Butterfly Garden reserves the right to delete comments that it deems inappropriate for any reason. Comments are moderated and publication times may vary.