Symbioses of grasses and fungal endophytes constitute an interesting model for evolution of mutualism and parasitism. Grasses of all subfamilies can harbor systemic infections by fungi of the family Clavicipitaceae. Subfamily Poöideae is specifically associated with epichloë endophytes (species of Epichloë and their asexual derivatives, the Neotyphodium species) in intimate symbioses often char...

Warming climate has increased access of native bark beetles to high-elevation pines that historically received only intermittent exposure to these tree-killing herbivores. Here we show that a dominant, relatively naïve, high-elevation species, whitebark pine, has inferior defenses against mountain pine beetle compared with its historical lower-elevation host, lodgepole pine. Lodgepole pines res...

Bark beetle species within the scolytid genera Dendroctonus, Ips, Pityogenes and Tomicus are known to cause extensive ecological and economical damage in spruce and pine forests during epidemic outbreaks all around the world. Dendroctonus ponderosae poses the most recent example having destroyed almost 100,000 km² of conifer forests in North America. The success and effectiveness of scolytid sp...

Nymphs of the western black-legged tick, Ixodes pacificus, were found on the trunks of trees during spring and summer in northwestern California. In a woodland-grass habitat, large- and medium-sized (> 130 cm and 80-130 cm in circumference, respectively), moss-covered oak (Quercus spp.) trees supported ticks significantly more often than trees without these characteristics. Additionally, trees ...

A new forest disease called Sudden Oak Death, caused by the pathogen Phytophthora ramorum, occurs in coastal hardwood forests in California and Oregon. In this paper, we analyzed the spatial–temporal patterns of overstory oak tree mortality in China Camp State Park, CA over 4 years using the point patterns mapped from high spatial resolution remotely sensed imagery. Both univariate and multivar...

The composition of the arthropod fauna foraging within the canopy of Argyrodendron actinophyllum Edlin (Sterculiaceae) in a subtropical rainforest near Brisbane, Australia, was investigated during a 2-year field study. Collecting methods included flight interception traps, restricted canopy fogging, and hand-collecting. Over 50 000 canopy arthropods were collected and about 760 species sorted, ...

This paper provides an updating of information a selected number major phytoplasma diseases forest trees, with focus on the associated taxa. Phytoplasma trees have been less extensively studied than those affecting fruit trees. Research role phytoplasmas as cause has only in last few years intensified, after sensitive and specific detection methods greatly based PCR technology became available....

Question: What are the qualitative and quantitative long-term changes in the vascular epiphyte assemblage on a particular host tree species? Location: Lowland rain forest of the San Lorenzo Crane Plot, Republic of Panama. Methods: We followed the fate of the vascular epiphyte assemblage on 99 individuals of the palm Socratea exorrhiza by three censuses over the course of five years. Results: Th...

Studies were conducted in 1997 and 1998 to evaluate the effects of three particle film formulations consisting of kaolin and adjuvants on neonate larvae, ovipositing adult females, and eggs of the codling moth, Cydia pomonella (L.). Neonate larval walking speed, fruit discovery rate, and fruit penetration rate on apple host plants coated with particle films were significantly lower than on host...

A recent outbreak of mountain pine beetle (MPB) has spread over more than 25 million hectares of pine forests in western North America, affecting pine species of sensitive boreal and mountain ecosystems. During initial host colonization, female MPB produce and release the aggregation pheromone trans-verbenol to coordinate a mass attack of individual trees. trans-Verbenol is formed by hydroxylat...