Review of the species of Aclees described by Kȏno (Coleoptera: Curculionidae: Molytinae).

Lectotypes and paralectotypes of Aclees taiwanensis Kȏno, 1933 and A. hirayamai Kȏno, 1933 are designated and illustrated. The holotype of A. saipanensis Kȏno, 1942 is illustrated.

A new species of Aclees from Taiwan with notes on other species of the genus (Coleoptera: Curculionidae: Molytinae).

A molecular and morphological analysis of the species of Aclees native to Taiwan allowed for recognition of a new species, that is described here as Aclees aenigmaticus Meregalli Boriani, sp. n. The study also revealed that the species of Aclees that has been introduced into Italy and France has identical morphology and mitochondrial cox-1 gene sequence with specimens of A. taiwanensis from Taiwan. Taiwan is thus assumed to be the country of origin of the specimens introduced into Europe. A key to the species of Aclees present in Taiwan is provided. A lectotype is designated for Aclees foveatus Voss, 1932, and some remarks on A. hirayamai Kôno, 1932 are given. Pagiophloeus visayus Heller, 1929 from the Philippines is transferred to the genus Aclees, comb. n.

Secondary contact and admixture between independently invading populations of the western corn rootworm, Diabrotica virgifera virgifera in Europe.

The western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), is one of the most destructive pests of corn in North America and is currently invading Europe. The two major invasive outbreaks of rootworm in Europe have occurred, in North-West Italy and in Central and South-Eastern Europe. These two outbreaks originated from independent introductions from North America. Secondary contact probably occurred in North Italy between these two outbreaks, in 2008. We used 13 microsatellite markers to conduct a population genetics study, to demonstrate that this geographic contact resulted in a zone of admixture in the Italian region of Veneto. We show that i) genetic variation is greater in the contact zone than in the parental outbreaks; ii) several signs of admixture were detected in some Venetian samples, in a bayesian analysis of the population structure and in an approximate bayesian computation analysis of historical scenarios and, finally, iii) allelic frequency clines were observed at microsatellite loci. The contact between the invasive outbreaks in North-West Italy and Central and South-Eastern Europe resulted in a zone of admixture, with particular characteristics. The evolutionary implications of the existence of a zone of admixture in Northern Italy and their possible impact on the invasion success of the western corn rootworm are discussed.