The first record of Reticuliterms flavipes (Kollar) (Isoptera: Rhinotermitidae) in Europe was in 1837, in Vienna, Austria, after infested plants imported from the U.S. were discovered in the greenhouse of the Schönbrunn Palace (Kollar 1837). In 1924, R. flavipes was found on the French Atlantic coast and initially described as a new species, R. santonensis (Feytaud 1924). The synonymy of R. santonensis with R. flavipes was eventually confirmed by mitochondrial DNA analyses (Austin et al. 2002). In France, R. flavipes is currently distributed in an area extending from the Gironde region up to Paris and Normandy, and causes structural damage to buildings and trees (Lohou et al. 1997). During the 1930s, R. flavipes was discovered in wooden forepoles of channel construction in the steam heating district of Hamburg, Germany, where populations were supported by the favorable microclimate (Weidner 1937). Today, populations of R. flavipes remain established in Hamburg, and cause damage to buildings and trees (Hertel & Plarre 2006).
In Oct 2008, a subterranean termite infestation was discovered by a homeowner in a detached house and adjacent garden situated in a residential district built in the 1970s in the outskirts of Olgiate Olona (Varese), in northern Italy. Termite workers and soldiers were observed and collected during a structural inspection in Nov 2008. Specimens are maintained in the Marini termite collection at the University of Bologna.
TABLE 1.
GENBANK SEQUENCES MATCHING OLGIATE OLONA COII AND 16S SEQUENCES.
Molecular analysis was used to determine the termite species, which were preserved in 100% ethanol prior to DNA extraction. A 684-bp region of the mitochondrial cytochrome oxidase subunit II gene and a 491-bp region of the mitochondrial 16S ribosomal RNA gene were amplified by PCR. Sequencing was performed by Macrogen Inc. (Seoul, South Korea). Closely related sequences were identified from GenBank using the BLAST network service (Altschul et al. 1990) at NCBI.
For both genes, nucleotide sequences were identical in the 2 workers (GenBank Accession GU070788 and GU070789). Sequences from the Olgiate Olona house corresponded (97–100% coverage, 100% similarity for COII sequence; 92– 100% coverage, 100% similarity for 16S sequence) to GenBank sequences of R. flavipes from North America and France and of A. arenincola Goellner (Table 1). This latter species appears to be identical to R. flavipes based on the DNA sequences obtained so far.
In North America, 47 16S haplotypes of R. flavipes have been described (Austin et al 2005a). Reticulitermes flavipes in France shows only 4 haplotypes (F, M and GG in Austin et al. 2005b, and another haplotype in Marini & Mantovani 2002), all of which can be found in North America, so it can be assumed that the European R. flavipes is allochthonous (non-native) (Austin et al. 2005a). French haplotypes can be found within or near the Mississippi River basin region of the U.S. once belonging to the French colonial empire in North America. In particular, 3 French haplotypes occur in Louisiana and Arkansas, and 2 French haplotypes are in Mississippi, Texas, Kansas, Oklahoma, Iowa, and Indiana (Austin et al. 2005a). Introduction of R. flavipes to France might date from the colonial period.
The Olgiate Olona sample shares the same 16S haplotype with French and USA populations (Table 1). Even though the possibility of an American origin for the Olgiate Olona population cannot be ruled out, it seems much more likely that R. flavipes was introduced to Italy from France because of the geographical proximity and history of trade activity between the 2 countries.
The human-aided introduction of R. flavipes to non-endemic regions of the world, such as Olgiate Olona, should be carefully monitored in order to identify and treat new infestations to prevent future introductions, especially because R. flavipes is a major structural pest wherever it has been introduced.
SUMMARY
An existing infestation of subterranean termites in and around a home in northern Italy was genetically determined to be the Nearctic species, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae). This is the first report of an established R. flavipes population in Italy. The source of the R. flavipes introduction is unknown.