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Abstract Full Text

A preliminary assessment of the occurrence and diversity of mitochondrial coi haplotypes in adventive populations of the biocontrol agent, Neodryinus typhlocybae, in Hungary.

Abstract

The parasitoid Neodryinus typhlocybae (Ashmead) (Hymenoptera Dryiinidae) was originally introduced from the USA to Italy in 1987 as a classical biological control agent for Metcalfa pruinosa (Say) (Hemiptera Flatidae). Additional releases and intentional redistribution of N. typhlocybae throughout Italy, as well as several European countries took place over a period of two decades. In 2014, this parasitoid was found in Hungary for the first time, despite the fact that, intentional releases in this country are not known to have occurred. To investigate the haplotype occurrence and diversity of N. typhlocybae in Hungary, the COI barcode region was characterized from established populations collected in Hungary. To determine whether the Hungarian populations of N. typhlocybae share haplotypes with populations released in classical biological control efforts for M. pruinosa in Italy, samples from three additional locations were obtained for comparison. This includes two locations in Italy where N. typhlocybae from Connecticut was released in the 1990's: Lazio, where samples were obtained from collections made in 2003 (i.e., shortly after successful parasitoid establishment), and more recent collections from Piedmont; and one location in Texas, USA where additional N. typhlocybae were collected and released in Italy in the late 1990's. Among the 250 samples collected, a total of 5 COI haplotypes were observed, with haplotype H2 accounting for 51% of the samples. Four haplotypes (H1, H2, H4, H5) were found in Hungary, with 71% belonging to haplotype H2, which was also the dominant haplotype from samples collected in Texas. Two haplotypes (H1 and H5) observed among Hungarian N. typhlocybae samples were also observed from samples collected in Lazio and Texas; H1 was also observed in the Piedmont samples. Haplotype H4 was observed (albeit at very low proportions) from collections in Hungary and Piedmont, but was not present among samples from Texas or Lazio. Although the results are preliminary, haplotypes H1, H2, and H5 in Hungary are consistent with populations associated with biological control releases in Italy that originated from Connecticut and Texas. Additional investigation is needed to determine whether releases in France from other source populations may have contributed to additional diversity, in particular in relation to the occurrence of H4. A more extensive collection and analysis of samples from across the geographic range of N. typhlocybae in both the area of origin (North America) and the area of introduction (across Europe) would be necessary to determine the origin(s) of the populations in Hungary, and to capture the full diversity of COI haplotypes in both the area of introduction and the area of origin.