Treesearch

Mature colonies of Reticulitermes spp. reproduce and spread mainly by secondary (rather than alate) reproductives throughout their geographical distribution, but especially near the northern boundaries of their range. Historically in Wisconsin, winged reproductives of the one established species, Reticulitermes flavipes (Kollar), have been noted only a few times in ground-dwelling colonies and are thus not thought to spread in this manner. Previous research suggests that populations in Wisconsin were introduced by anthropogenic movement of infested materials, a hypothesis supported by...

Nanofibrillated cellulose (NFC) is a renewable and biodegradable fibril that possesses high strength and stiffness resulting from high level hydrogen bonding. Films made from NFC shrink and distort as they transition from a wet state (20 wt% solids) to a state of moisture equilibrium (90 wt% solids at 50 % RH, 23 °C). Material distortions are driven by development of moisture gradients within the fibril network and effectively reduce mechanical performance. For this study, NFC was extracted from softwood holocellulose by first employing a chemical pretreatment [(2,2,6,6tetramethylpiperidin-...

The catastrophic fires and tragic losses during the 2013 fire season have resulted in many discussions about fire management policies aimed at protecting communities and restoring fire-resilient forests from the growing incidence of severe wildfires. Forest Service scientist Alan Ager has been exploring how concepts in spatial ecology and operations research can be used to better prioritize fuel management and restoration projects and design landscape fuel treatment strategies. This work has yielded a new model and software program called the Landscape Treatment Designer (LTD) and a case...

Smoke from wildfires has adverse biological and social consequences, and various lines of evidence suggest that smoke from wildfires in the future may be more intense and widespread, demanding that methods be developed to address its effects on people, ecosystems, and the atmosphere. In this paper, we present the essential ingredients of a modeling system for projecting smoke consequences in a rapidly warming climate that is expected to change wildfire regimes significantly. We describe each component of the system, offer suggestions for the elements of a modeling agenda, and provide some...

The woodwasp Sirex noctilio F. (Hymenoptera: Siricidae) has become established in North America. A primary tactic for the management of S. noctilio in the southern hemisphere has been the development of a biological control agent, Deladenus siricidicola Bedding. This nematode has a bicyclic life cycle including a mycetophagous free-living and parasitic cycle. During oviposition, female Sirex woodwasps inject a symbiotic fungus. Because D. siricidicola only develops well on Amylostereum areolatum (Chaillet ex Fries) Boidin (Russulales: Amylostereaceae) and North American woodwasps were...

Savanna and woodland were once common in the Midwest, but land use changes have led to increasing scarcity of these communities. These transitional habitats are being restored across the Midwest, but few studies have evaluated the response of wildlife to restoration or the vegetative gradient created by management. We conducted point counts for 25 songbirds at sites undergoing savanna or woodland restoration and nearby non-managed forest sites across the Ozark Highlands of Missouri during the 2009-2011 breeding seasons; these sites represented a gradient of canopy cover and tree density...

Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV) has been formulated and applied to control outbreaks of the gypsy moth, L. dispar. To classify and determine the degree of genetic variation among isolates of L. dispar NPVs from different parts of the range of the gypsy moth, partial sequences of the lef-8, lef-9, and polh genes were determined for Lymantria spp. virus samples from host populations throughout the world. Sequence analysis confirmed that all L. dispar virus samples tested contained isolates of the species Lymantria dispar multiple nucleopolyhedrovirus (Baculoviridae:...

The concept of ecosystem services from landscapes is rapidly gaining momentum as a language to communicate values and benefits to scientists and lay alike. Landscape ecology has an enormous contribution to make to this field, and one could argue, uniquely so. Tools developed or adapted for landscape ecology are being increasingly used to assist with the quantification, modelling, mapping, and valuing of ecosystem services. Several of these tools and methods encased therein are described among the eleven papers presented in this special issue, and their application has the potential to...

The role that mites play in many ecosystems is often overlooked or ignored. Within bark beetle habitats, more than 100 mite species exist and they have important impacts on community dynamics, ecosystem processes, and biodiversity of bark beetle systems. Mites use bark beetles to access and disperse among beetle-infested trees and the associations may range from mutualistic to antagonistic, and from facultative to obligate. Many of these mites are mycetophagous, feeding on ophiostomatoid fungi found in beetle-infested trees and carried by bark beetles.

Although insects, pathogens, mites, nematodes, weeds, vertebrates, and arthropods are different in many ways, they are regarded as pests. They are a major constraint to crop productivity and profitability around the world caused by direct and indirect damage to valuable crops. Insect pests, pathogens, and weeds account for an estimated 45% of pre- and post-harvest losses worldwide (Pimentel, 1991), in addition to losses caused by vertebrate pests (Strand, 2000). Each year, farmers are confronted with several questions and uncertainties on how best to manage potential threats posed by pests...