Dyar's law

Dyar's Law is the observed standard that during development of the immature stages of an insect, increases in highly sclerotized body parts are predictable and regular by a relatively constant factor.[1] The law is named for Harrison G. Dyar who in 1890 published a paper about his observation that the head capsule widths of lepidopteran larvae follow a geometric progression in growth.[2]

Though the progression can be influenced by abiotic and biotic factors such as temperature and food,[3] Dyar's Law can be accurately used to differentiate instars of immature insects and to predict the size of instars missing from samples, crucial data for accurately delineating insect developmental histories.

Although initially based on observations of lepidopterous larvae, Dyar's Law has been applied to immature insects in general.[1] Some 80% of entomological studies published from 1980 to 2007 that examined the validity of Dyar's observations supported the law.[1]

References

  1. ↑ 1.0 1.1 1.2 Vincent H. Resh and Ring T. Cardé (eds.). 2009. Encyclopedia of insects, Second Edition, Academic Press, Burlington, Mass., pp. 432–433; http://books.google.com/books?id=Jk0Hym1yF0cC&pg=PA432&lpg=PA432&dq=%22Dyar%27s+Law%22&source=bl&ots=Tw_Si1z3rO&sig=EdXhEGNK9GxBtatAyBANcFDyvN4&hl=en&sa=X&ei=YeEuT5y5MIetgwfE38HfDw&ved=0CFoQ6AEwCQ#v=onepage&q=%22Dyar%27s%20Law%22&f=false, accessed 5 Feb 2012.
  2. ↑ Harrison G. Dyar. 1890. The number of molts of lepidopterous larvae. Psyche 5:420–422.
  3. ↑ C. P. Klingenberg and M. Zimmermann. 1992. Dyar's rule and multivariate allometric growth in nine species of waterstriders (Heteroptera: Gerridae). Journal of Zoology, London 227, 453–464.