Fifteen transgenic birch lines carrying a chitinase IV gene from sugar beet and non-transgenic control plants were grown in a field trial, and traits connected to growth, quality and adaptation were monitored. Significant variation among the transgenic lines was observed in the growth parameters as ...

Wood properties vary within trees as a result of to changing environmental conditions and phase change during growth. Certain wood properties are important depending on the end use of the tree. If a tree is required for timber purposes then the structure should convey high stiffness. Conversely if...

The larvae of the agromyzid flies that belong to the genus Phytobia feed by mining in the differentiating xylem just below the cambium of growing forest trees. The genus, which is apparently one of the most primitive groups in the Agromyzidae, comprises over 50 currently recognized species. Most of ...

The colonization success of herbivorous insects depends partly on the ability of females to choose suitable host plants. P. betulae, a miner of differentiating xylem, infests birch (B. pendula and B. pubescens) trees. In a field experiment, conducted in Finland during 1995, we measured successful...

Structural abnormalities and anatomical changes in the wood of Betula pendula caused by the larvae of Phytobia betulae were examined by light microscopy. In each tree, the number of larval tunnels increased greatly from the crown region towards the base. In the transverse section, larval tunnels...

Larvae of Phytobia betulae (Diptera: Agromyzidae) mine within the differentiating xylem tissue near the vascular cambium of birch trees. These larvae start in the canopy and move toward the base of the stem, leaving permanent brown tunnels in the wood. This study was conducted to test whether young ...

Larvae of Phytobia betulae mine within the differentiating xylem tissue of birch trees from canopy to stem base, resulting in permanent brown tunnels in the wood. In birch products the tunnels are considered to be an aesthetic defect. The aim of the study was to determine whether European white...

The feeding scars of a wood-mining herbivorous insect (the agromyzid Phytobia betulae) of birch trees (Betula pendula and Betula pubescens) provided long time series data (47 and 65 years) of absolute abundance (larvae/tree) in replicated trees within replicated stands in Finland. Measurements of...

Larvae of Phytobia betulae (Diptera: Agromyzidae) mine in birch wood near the cambium layer and cause brown streaks in the wood. The streaks reduce the value of birch wood used in plywood and the furniture industry. In cross sections of birch logs the streaks are seen as pith flecks. Both European...