The yellow-necked drywood termite, Kalotermes flavicollis (F.), so called due to the yellow pronotum of its alates, is the only species in the genus Kalotermes known for Europe. In some Italian localities, K. flavicollis swarms can contain a small proportion of alates with a dark pronotum, but otherwise not different from the normally colored K. flavicollis. This color variation was described by G. Becker in 1955 as Kalotermes flavicollis var. fuscicollis. During collecting trips in central Italy, we found in Grosseto Marina (Tuscany) a Kalotermes population whose alates all have a very dark pronotum. Compared with K. flavicollis alates, Grosseto alates also have paler wings and smaller arolia. Grosseto soldiers have eyes smaller than those of K. flavicollis soldiers. Kalotermes sp. form Grosseto also differs morphologically from the other Kalotermes species known for the circum-Mediterranean lands. The population from Grosseto has mitochondrial DNA sequences (a partial sequence of the control region and a fragment including a portion of COI, tRNA-Leu and a portion of COII) quite different from K flavicollis (p-distance: 5.6–7.3%). Some Kalotermes populations from Tuscany and Marche, morphologically classifiable as K flavicollis, have sequences similar to those of Grosseto Kalotermes (p-distance: 0.1–1.0%). These populations are possibly hybrids between K. flavicollis and Kalotermes sp. from Grosseto. Because of its morphologic and genetic distinctive features, we describe Kalotermes sp. from Grosseto as Kalotermes italicus sp. nov.