Effects of salt-treated wood on feeding and survivorship in subterranean termites (Rhinotermitidae: Reticulitermes) from coastal and inland forests

Subterranean termites in coastal tidal forests are repeatedly subjected to inundation by brackish water. We examined the effects of salt-treated wood on termites from a coastal tidal pine forest and from an inland pine forest. In laboratory no-choice tests, salt concentrations of 1% and 3% (w/w) applied to pine blocks had deleterious effects on survivorship and food consumption in termites from both habitats. Inland termites had greater survivorship and wood consumption than coastal termites in no-choice tests. In choice tests, termites did not discriminate between water-treated wood or salt-treated wood. In no-choice tests using lower salt concentrations, coastal termites were harmed by 0.5% salt but not 0.1% concentrations. They did not discriminate between wood that was water-treated or treated with 0.5% salt in choice tests, however. Wood chloride levels were significantly higher in the coastal site than in the inland site. Within sites, wood with or without termites did not differ significantly in chloride content. These results indicate that neither coastal nor inland Reticulitermes discriminate against deleterious levels of salt in their foods, even though termites from coastal habitats are naturally exposed to saltier wood than inland termites.