Rangewide variation of the maritime pine bast scale Matsucoccus feytaudi Duc. (Homoptera : Matsucoccidae) in relation to the genetic structure of itshost

The bast scale Matsucoccus feytaudi is a specific pest of maritime pine, bu t the damage inflicted by the insect on the host trees is variable, ranging from no apparent effect to severe decline of the maritime pine stands. Ran gewide variation of mitochondrial DNA among M. feytaudi populations was ana lysed by polymerase chain reaction-restriction fragment length-single-stran d conformation polymorphism (PCR-RFLP-SSCP) analysis and the results compar ed with the genetic information already available for its host. Three main nonoverlapping lineages can be distinguished in M. feytaudi. The phylogeogr aphy of the pest population is clearly related to the history of its host. Most local associations could result from common evolution while others mus t be interpreted as intraspecific host shifts. Because the distribution of cultivated tree species is greatly influenced by humans, much may be learne d concerning their genetic structure from the indirect study of their speci fic pests.