No abstract

Firewood can serve as a vector in the transport of non-native species, including wood-boring insects that feed within the wood and thus can be transported accidentally. Governments have enacted limitations on the movement of firewood in an effort to limit the anthropogenic movement of non-native species through, for example, recreational camping. Although the movement of invasive species through firewood is a documented invasion pathway, it is not trivial for governments to determine a "safe" allowable distance for moving firewood. We were motivated by this challenge and developed a theoretical simulation to determine the campgrounds that could be potentially exposed to infested firewood based upon the hypothetical distribution of an invasive species and the allowable distance for moving firewood. We extend this concept to the known distributions of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) and Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) Coleoptera: Cerambycidae). We illustrate, based upon theoretical and empirical observations, that as the distribution of an invasive species increases, more rigid constraints on the movement of firewood would be required relative to those species that are distributed over a smaller scale. Also, on the level of management within a state, smaller states have far less margin for error than larger ones, as even extremely rigid restrictions on the movement of firewood could have little management effect unless the infested area is spatially limited. These results collectively suggest the potential for a dynamic management strategy that adjusts allowable distances for firewood movement based upon the distribution of the non-native species.

This paper describes a program of policy management and research from 2006 through 2015. It focuses on regulator efforts to understand and address challenges presented by dispersal of forest diseases and invasive pests in firewood by the camping public. Five surveys conducted at two-year intervals informed these efforts. The first survey in 2006 benchmarked campers' awareness of forest threats by invasive species, their evaluations of firewood supplied at and near Wisconsin state parks, and their compliance with firewood movement rules which had been implemented that year. The 2008 survey tested for improvements in awareness and compliance and investigated campers' motivations. The motivation research showed that calculated, normative, and social motivations are all important to rule compliance in the camping context. Surveys in 2010, 2012, and 2014 confirmed these results and guided education and outreach efforts, adjustments to firewood movement rules for Wisconsin state parks and forests, and improvements to firewood supplies at state campgrounds. The survey sequence as a whole revealed that: (1) compliance improves dramatically in early program years and then levels off, suggesting that it may be unrealistic and cost ineffective to strive for 100% compliance in similar regulatory contexts; (2) persistence in messaging is important in building awareness and motivation; and (3) regulation and persuasion based on motivational principles can extend beyond specific situations where informing and regulating take place, suggesting that public properties can be useful venues for encouraging other types of environmentally responsible behavior.

While emphasis with entomopathogens has often been on inundative releases, we describe here historic widespread inoculative releases of a fungal entomopathogen. Several U.S. states and municipalities conducted inoculative releases of the gypsy moth, Lymantria dispar (L.) (Lepidoptera: Erebidae), pathogen Entomophaga maimaiga Humber, Shimazu et Soper (Entomophthorales: Entomophthoraceae) after 1993, as gypsy moth populations spread into the Midwest and North Carolina. This Japanese pathogen first caused epizootics in northeastern North America in 1989 and methods for its inoculative release were tested and proven to be effective from 1991 to 1993. After 1993, spores in soil or in late instar cadavers were collected during or after epizootics and were released inoculatively into newly established populations of this spreading invasive; the goal was that spores would overwinter and germinate the next spring to infect larvae, thus speeding pathogen spread and hastening the development of epizootics in newly established populations. The fungus was released in gypsy moth populations that were separated from areas where the fungus was already established. In particular, extensive releases by natural resource managers in Wisconsin and Michigan aided the spread of E. maimaiga throughout these states. Where it has become established, this acute pathogen has become the dominant natural enemy and has exerted considerable influence in reducing gypsy moth damage. While this pathogen most likely would have invaded these new regions eventually, releases accelerated the spread of E. maimaiga and helped to reduce impacts of initial outbreaks, while further outbreaks were reduced by the pathogen’s subsequent persistence and activity in those areas.

No abstract