According to the coevolution theory of autumn colours, the bright colours of leaves in autumn are a warning signal to insects that lay their eggs on the trees in that season. If the colour is linked to the level of defensive commitment of the tree and the insects learn to avoid bright colours, this may lead to a coevolutionary process in which bright trees reduce their parasite load and choosy ...

Manipulation of host behavior by parasites and pathogens has been widely observed, but the basis for these behaviors has remained elusive. Gypsy moths infected by a baculovirus climb to the top of trees to die, liquefy, and "rain" virus on the foliage below to infect new hosts. The viral gene that manipulates climbing behavior of the host was identified, providing evidence of a genetic basis fo...

Aim It has been proposed that co-invasion with ectomycorrhizal (EM) fungi is a common mechanism by which non-indigenous trees overcome symbiont limitation, yet virtually all prior evidence has come from a single plant family, the Pinaceae. We tested the co-invasion hypothesis by examining the EM fungal communities associated with a specialized host, Alnus glutinosa (black alder), and a generali...

An interactive application responds to aperiodic user input with computation that can be expressed as activation trees. By bounding the execution time of these trees, we can improve the responsiveness of the application. The application runs in a typical computing environment: a group of uncoordinated but measurable hosts interconnected with a measurable local area network. The environment serv...

Chemical analyses were conducted to determine the qualitative and quantitative differences in monoterpenes and sesquiterpenes in plant material from avocado trees, Persea americana Mill. (Lauraceae). The initial study analyzed plant material sampled from the trunk to the leaves through different branch diameters to quantify proximo-distal spatial differences within a tree. All trees were seedli...

Lianas (woody vines) reduce growth and survival of host trees in both temperate and tropical forests; however, the relative strength of liana-tree competition in comparison to tree-tree competition remains unexplored. When controlling for biomass, lianas may have greater competitive effects than trees because the unique morphology of lianas allows them to reach the forest canopy at relatively s...

Predicting future risks of damage by insect pests is an important aspect of forest management. Climate change has the potential to affect forest pests and their impact on trees through higher temperatures, altered precipitation patterns, and more frequent extreme weather events. Warmer temperatures are likely to have complex effects on insects, influencing, among other things, development rate ...

Bark beetles use aggregation pheromones to promote group foraging, thus increasing the chances of an individual to find a host and, when relevant, to overwhelm the defences of healthy trees. When a male beetle finds a suitable host, it releases pheromones that attract potential mates as well as other 'spying' males, which result in aggregations on the new host. To date, most studies have been c...

This paper shows how to embed complete binary trees in products of complete binary trees products of shu e exchange graphs and products of de Bruijn graphs The main emphasis of the embedding methods presented here is how to emulate arbitrarily large complete bi nary trees in these product graphs with low slowdown For the embedding methods presented here the size of the host graph can be xed to ...

The spatial influences of host and nonhost trees and shrubs on the colonization patterns of white pine weevil Pissodes strobi (Peck) were studied within a stand of planted interior hybrid spruce [Picea glauca (Moench) Voss x Picea engelmannii (Parry) ex Engelm.]. Planted spruce accounted for one third of all trees within the stand, whereas the remaining two thirds were comprised of early-succes...