The systematic formulation of population models for insects with dynamically varying instar duration

R.M. Nisbet, William Gurney

Research output: Contribution to journalArticlepeer-review

134 Citations (Scopus)


We develop a formalism for insect population dynamics which covers the situation where maturation from one instar to its successor is triggered by weight gain and not by chronological age. We specify assumptions which result in the instantaneous “subpopulations” of various instars obeying delay-defferential equations with time delays (representing instar duration) which are themselves dynamic variables, changing in response to the availability of food. We demonstrate the stabilizing potential of variable time delays by studying an idealised two-stage model in which maturation to the adult stage occurs after absorption of a given (fixed) quantity of food.
Original languageEnglish
Pages (from-to)114-135
Number of pages22
JournalTheoretical Population Biology
Issue number1
Publication statusPublished - Feb 1983


  • insect population dynamics
  • dynamic variables
  • instar duration

Cite this