caa a22 4500 463168321 CHVBK 20180406164806.0 cr unu---uuuuu 170326e20070601xx s 000 0 eng 10.1007/s10530-006-9039-z doi (NATIONALLICENCE)springer-10.1007/s10530-006-9039-z A geographically variable model of hemlock woolly adelgid spread [Elektronische Daten] [Alexander Evans, Timothy Gregoire] The hemlock woolly adelgid (HWA) (Adelges tsugae) has spread through the range of eastern hemlock (Tsuga canadensis) leaving dead hemlock trees in its wake. We combined county and previously unavailable township level infestation records with geographic variables including plant hardiness zone, elevation, forest cover type, urbanization, precipitation, temperature, and hemlock range in a geographic information system to build models linking HWA spread to the structure and characteristics of the environment. We explored the connections between site variables and spread rate using quantile regression, Tobit regression, a parametric model for heterogeneous error variance, and classification and regression tree modeling. The results show that since 1990 HWA has spread at a rate closer to 12.5km/yr rather than the 20-30km/yr previously estimated, however spread rates vary significantly with environmental variables. County-based data show a faster rate of range expansion in the south, 15.6km/yr, and very slow spread in the northern part of the current range of HWA. The rate of spread based on township records for Pennsylvania and north is 8.13km/yr. Our study suggests that HWA spreads more slowly in colder areas, with a mean minimum temperature of −26.1°C (plant hardiness zone 5B) delineating areas of slower range expansion. HWA also spreads more slowly during cold years, those with lower than average mean January temperatures. Our analysis demonstrates the value of quantile regression, Tobit regression, and classification and regression tree models for understanding the spread of invasive, exotic insects. Springer Science+Business Media B.V., 2006 Classification and regression trees nationallicence Invasive insect nationallicence Hemlock woolly adelgid nationallicence Range expansion nationallicence Quantile regression nationallicence Tobit regression nationallicence Evans Alexander School of Forestry and Environmental Studies, Yale University, 360 Prospect St., 06511, New Haven, CT, USA aut Gregoire Timothy School of Forestry and Environmental Studies, Yale University, 360 Prospect St., 06511, New Haven, CT, USA aut Biological Invasions Kluwer Academic Publishers 9/4(2007-06-01), 369-382 1387-3547 9:4<369 2007 9 10530 https://doi.org/10.1007/s10530-006-9039-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10530-006-9039-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Evans Alexander School of Forestry and Environmental Studies, Yale University, 360 Prospect St., 06511, New Haven, CT, USA aut NATIONALLICENCE 700 1- Gregoire Timothy School of Forestry and Environmental Studies, Yale University, 360 Prospect St., 06511, New Haven, CT, USA aut NATIONALLICENCE 773 0- Biological Invasions Kluwer Academic Publishers 9/4(2007-06-01), 369-382 1387-3547 9:4<369 2007 9 10530 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer