Portal de Periódicos da CAPES

Environmental Factors Affecting the Geographical Distribution of Two Ecologically Equivalent Termite Species in Arizona

1976; University of Notre Dame; Volume: 95; Issue: 1 Linguagem: Inglês

10.2307/2424230

1938-4238

Michael I. Haverty, William L. Nutting,

Ecology and Vegetation Dynamics Studies

Records of Heterotermes aureus (Snyder) and Reticuli- termes tibialis Banks in the insect collecion of the University of Arizona were used to plot precisely their distributions in Arizona. Seasonal and annual mean air temperature and precipitation for each locality were plotted to illustrate environmental limits of the two, species. Hetero- termes occurs in desert and desert grasslands below 1220 m while Reticu- litermes generally occurs in grassland, oak-pifion-juniper associations and coniferous forests above 1140 m. The distribution of H. aureus is lim- ited by the lower temperatures and higher elevations in the northern part of the state, whereas R. tibialis is limited by the low moisture and high temperatures of the lower deserts. Reticulitermes may invade areas occu- pied by Heterotermes under suitable moisture and temperature conditions provided by urban and riparian situations. Borrowing an approach from some innovative plant geographers, we have tried to explain the geographical distributions of Heterotermes aureus (Snyder) and Reticulitermes tibialis Banks in Arizona as re- sultants of interacting environmental parameters. The distributions of most termites are very imperfectly known from widely scattered collections, often from undocumented, parochial lists. Revisions, such as Ruelle's (1970) on Macrotermes, which include accurately desig- nated localities and accompanying information on rainfall and vegeta- tion are exceptional. The preliminary review of the termite genera in South West Africa by Coaton and Sheasby (1972) provides a basis for specific distributional analyses in the form of maps of the collecting districts, average annual rainfall, elevation and vegetation types, to- gether with descriptions and photographs of the latter. Dealing with the termites of the western United States, Kofoid (1934) contributed one of the few discussions of the effects of climatic factors on their local occurrence and geographical distribution. In this highly specula- tive area, Williams (1934) stands, out for having presented experimen- tal evidence toward a partial explanation for the distribution of two species of Reticulitermes. Termite colonies-indeed, perhaps the colonies of most typical social insects-have many characteristics in common with perennial plants. Colonies are generally stationary although they may grow and occupy variable territories. Dispersal is seasonal, local and usually accomplished by winged reproductive members of the colony. Large numbers of these alates may be produced, but relatively few survive to