Is there a role for termite alates in colony expansion in Wisconsin?
Termite colonies in Wisconsin tend to be large and widely spread out geographically, and separated by distances up to 1342km. We recently completed a study to determine the genetic diversity and population substructure of thirteen existing colonies of Reticulitermes flavipes using amplified fragment length polymorphism to determine patterns of termite dispersal in Wisconsin. Measures of inbreeding, heterozygosity, genetic variation, polymorphism and geographic distances showed that colonies had mixed characteristics of what was expected for colony expansion through budding versus multiple introductions at physically separate sites by means of alates or human movement of infested materials. Overall, these results did not provide evidence of colonies formed by alate breeding pairs. Instead, we hypothesize that R. flavipes is likely spread by anthropogenic means, including discarded rail ties, in Wisconsin. Nearly all known areas of termite activity in the state lie on or near major rail lines. A new generation of dual-treatment of crossties with water soluble borates overcoated with a second treatment of water insoluble (oil borne) copper napthanate or creosote may begin to limit transfer of insect colonies via Interstate commerce.