THE DISTRIBUTION OF THE THREE FORMS† OF THE MEAT ANT IRIDOMYRMEX PURPUREUS (HYMENOPTERA: FORMICIDAE) IN AUSTRALIA

Abstract

Distributions of the three nominal forms of the meat ant Iridomyrmex purpureus (Smith), I. viridiaeneus Viehmeyer and J. sanguineus Forel have been studied. Each ranges widely, and seems characteristically to be developed in areas within prescribed limits of rainfall and vegetation. The most common form, purpureus, is found over one third of the Australian mainland; it is sometimes found in association with the other two forms and in places it appears to occupy a buffer zone between areas where viridiaeneus or sanguineus are common. Examples of apparent character displacement are given, with discussion of how the variation in nest structure could enable colonies to survive extreme conditions. Evidence suggesting effects of soil, altitude, rainfall and vegetation in limiting the distribution of each form is discussed. Copyright © 1971, Wiley Blackwell. All rights reserved