The New Zealand spread and distribution of the South American weevils Floresianus sordidus Hustache and Atrichonotus taeniatulus (Berg)

The South American Flores weevil (Floresianus sordidus Hustache, 1939) and little fringed weevil Atrichonotus taeniatulus (Berg, 1881) (Coleoptera, Curculionidae) are now common in northern areas of the North Island of New Zealand. Historic records were investigated to determine the distribution and prevalence of these flightless weevils during five decades following their initial establishment in the Hawke’s Bay region in the late 1960s and early 1970s. Both were slow dispersers: the first detection outside Hawke’s Bay was in the 1990s and they were only confirmed present in Taranaki from 2017 onwards. Dispersal between regions likely occurred via human transport, with both detected for the first time in the South Island in 2000 at Christchurch airport. Based on the number of sites where the weevils have been collected, both species have been found more often in the warmer regions but will eventually colonise most of New Zealand. Parasitism by Microctonus aethiopoides Loan (Hymenoptera: Braconidae) was detected in A. taeniatulus adults but not in F. sordidus.