Changes in the distribution of pine wilt disease and the vector beetle Monochamus alternatus in the Tohoku region of northern Japan between 2012 and 2022

Abstract

To clarify the spread of pine wilt disease to unaffected area of the Tohoku region of northern Japan, researchers of six Tohoku prefectures (Fukushima, Miyagi, Yamagata, Akita, Iwate and Aomori) surveyed the distributions of dead Pinus thunbergii and P. densiflora trees killed by the pinewood nematode, Bursaphelenchus xylophilus and the vector beetle, Monochamus alternatus. Following on from the previous report from 2007 to 2011, the distributions of pine wilt disease and the vector beetle was surveyed from 2012 to 2022 by the researchers from each prefecture. These data were combined to yield the annual figures for the Tohoku region. During these 11 years, the distribution area newly infected with pine wilt disease has expanded to 11 districts and the insect’s distribution was also found in nine new districts.