from The American Heritage® Dictionary of the English Language, 4th Edition
- transitive v. To stud with or as if with stars.
- n. A stage of an insect or other arthropod between molts.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any one of the several stages of postembryonic development which an arthropod undergoes, between molts, before it reaches sexual maturity.
- n. An arthropod at a specified one of these stages of development.
- n. A stage in development.
- v. To stud with stars.
from the GNU version of the Collaborative International Dictionary of English
- n. a postembryonic stage of life of an arthropod, especially an insect, between two successive molts; also, the arthropod when in that stage of life.
- transitive v. To stud as with stars.
from The Century Dictionary and Cyclopedia
- To set or adorn with stars or with brilliants; star.
- To make a star of; set as a star.
- n. Any one of the periods of an insect's life between two molts. The period immediately after hatching is said to be the first instar, and that after the first molt the second instar. If a caterpillar molts four times the pupa is the sixth instar and the adult the seventh. The term originated with Fischer in 1853, but has only recently been generally adopted.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. an insect or other arthropod between molts
 The convenient term 'instar' has been proposed by Fischer and advocated by Sharp (1895) for the form assumed by an insect during a stage of its life-story.
Cage experiments with first instar larvae and eggs.
With each instar the nymph becomes progressively more like an adult cockroach.
The period between each molt is known as an instar.
In the final nymphal instar, they construct an exit tunnel to the surface and emerge.
You look at the maggots, and say things like "ah yes, that's a 2nd instar Protophormia terranovae, from which I deduce this man has been dead for between 32 and 43 hours."
As for pooping, the larva only poops once in its childhood, in that, the feces is stored at the end of the digestive tract as a superconcentrated pellet, and is only released after the molt of the second to final instar before pupating.
When these shots were taken, none had matured to the fifth instar stage of green and black bands with yellow spots along the black bands.
Fourth instar caterpillars look very different from the 2nd and 3rd instar.
Size range for 2nd instar is about 4.5 to 8 mm, for 3rd instar – 8mm to 13mm 1.3cm.