DOI: 10.5061/dryad.61c4h39
title: Data from: Disentangling the drivers of invasion spread in a vector-borne tree disease

description: 1. Pine wilt disease (PWD) invaded southern Japan in the early 1900’s and
 has gradually expanded its range to northern Honshu (Japanese mainland).
 The disease is caused by a pathogenic North American nematode, which is
 transmitted by native pine sawyer beetles. Recently the disease has
 invaded other portions of East Asia and Europe where extensive mortality
 of host pines is anticipated to resemble historical patterns seen in
 Japan. 2. There is a critical need to identify the main drivers of PWD
 invasion spread so as to predict future spread and evaluate containment
 strategies in newly invaded world regions. But the coupling of pathogen
 and vector population dynamics introduces considerable complexity that is
 important for understanding this and other plant disease invasions. 3. In
 this study, we analysed historical (1980-2011) records of PWD infection
 and vector abundance, which were spatially extensive but recorded at
 coarse categorical levels (none, low and high) across 403 municipalities
 in northern Honshu. We employed a multistate occupancy model that
 accounted both for demographic stochasticity and observation errors in
 categorical data. 4. Analysis revealed that sparse sawyer populations had
 lower probabilities of transition to high abundance than did more abundant
 populations even when regional abundance stayed the same, suggesting the
 existence of positive density dependence, i.e. an Allee effect, in sawyer
 dynamics. Climatic conditions (average accumulated degree days)
 substantially limited invasion spread in northern regions, but this
 climatic influence on sawyer dynamics was generally weaker than the Allee
 effect. 5. Our results suggest that tactics (e.g., sanitation logging of
 infected pines) which strengthen Allee effects in sawyer dynamics may be
 effective strategies for slowing the spread of PWD.
description: Pine wilt disease and
 vector beetle records in northern JapanThis is the Microsoft
 excel file containing the information of the incidences of pine wilt
 disease, of the abundance of sawyers and of the location. All the data of
 PWD incidences and sawyer densities were extracted from FFPRI repository
 (https://www.ffpri.affrc.go.jp/pubs/bulletin/433/documents/433-9.pdf)
 (Forest Conservation Departmental Meeting of Tohoku Forestry Research
 Institute Liaison Council, 2008, 2014). The "pwd" sheet has the
 abundance of newly infected trees, 0 (0 infected trees / municipality), 1
 (1-10 trees / municipality), 2 (11-100 trees / municipality) and 3
 (&gt;100 trees / municipality) in each year (column) at each municipality
 (row). The "beetle" sheet has the abundance of sawyers, 0 (0
 sawyer), 1 (low abundance) and 2 (high abundance) in each year (column) at
 each municipality (row). The "info" sheet has the information of
 the municipalities. Citycode is the municipality codes used in the other
 sheets. The Lon and Lat are the longitude and the latitude of the
 centroids of the municipalities in JGD2011 (The Japanese Geodetic Datum
 2011), respectively. Municipality is the names of municipalities in each
 District of each Prefecture. Villages and towns are classified in
 Districts but cities are directly belonging to
 Prefectures.2018OsadaJAE.Ver2.xlsx