Reactions of Heracleum Lanatum to Floral Herbivory by Depressaria Pastinacella

Ecology ◽  
1984 ◽  
Vol 65 (1) ◽  
pp. 191-197 ◽  
Author(s):  
Stephen D. Hendrix
Keyword(s):  
Depressaria Pastinacella ◽  
Floral Herbivory ◽  
Heracleum Lanatum

Interactions among nectar robbing, floral herbivory, and ant protection inLinaria vulgaris

Oikos ◽  
2005 ◽  
Vol 110 (3) ◽  
pp. 497-506 ◽  
Author(s):  
Daniel A. Newman ◽  
James D. Thomson
Keyword(s):  
Nectar Robbing ◽  
Floral Herbivory

The diet of grizzly bears in the Flathead River drainage of southeastern British Columbia

1995 ◽  
Vol 73 (4) ◽  
pp. 704-712 ◽  
Author(s):  
Bruce N. McLellan ◽  
Fred W. Hovey
Keyword(s):  
National Park ◽  
Ursus Arctos ◽  
Handling Time ◽  
Early Spring ◽  
Early Summer ◽  
Grizzly Bears ◽  
Green Vegetation ◽  
Heracleum Lanatum ◽  
Shepherdia Canadensis ◽  
Food Consumed

Based on the analysis of 1100 feces or scats, the seasonal diet of grizzly bears (Ursus arctos) in the Flathead drainage between 1979 and 1991 was estimated. In the early spring, major foods included ungulates and hedysarum roots (Hedysarum sulphurescens). Later in the spring and early summer, green vegetation that mainly included horsetails (Equisetum arvense), graminoids, and cow parsnip (Heracleum lanatum) dominated the diet. Later in the summer, berries, particularly huckleberries (Vaccinium spp.) and soopolallie (Shepherdia canadensis), were most common. In the autumn, berries, ungulates, and hedysarum roots were major foods. Seasonal changes in nutrients were measured for major foods. The volume of a food consumed within a season was inversely related to food quality, suggesting that food availability and handling time may have been more important factors influencing diet selection. The proportions of food items in the scats, and species of fruit in particular, varied among years. The Flathead and contiguous Waterton Lakes National Park are so far the only study areas in North America that contain all major bear foods found across the interior of the continent, and in particular, both major berry species, huckleberries and soopolallie. This observation supports the hypothesis that a favourable food base in the Flathead is partially responsible for the high density of bears found there. It is important for managers to realize the possible uniqueness of the Flathead area and not extrapolate information without due caution.

The biosynthesis of isopimpinellin

1977 ◽  
Vol 55 (7) ◽  
pp. 686-692 ◽  
Author(s):  
Stewart A. Brown ◽  
Saroja Sampathkumar
Keyword(s):  
Cell Cultures ◽  
Double Labelling ◽  
Ruta Graveolens ◽  
Methyl Group ◽  
Carbon 14 ◽  
Heracleum Lanatum ◽  
High Degree

Bergapten and xanthotoxin, labelled in the methyl group with carbon-14 or tritiated at three skeletal carbons, were administered to leaves of Heracleum lanatum and to cell cultures of Ruta graveolens. In all experiments xanthotoxin was the more efficient precursor of isopimpinellin, although bergapten was always incorporated to a measurable extent. Double-labelling experiments showed that both precursors, especially bergapten, underwent considerable demethylation (and presumably remethylation) before conversion to isopimpinellin. 5-Hydroxyxanthotoxin and 8-hydroxybergapten were both O-methylated by cell-free extracts of Ruta cells to isopimpinellin, in reactions mediated by discrete O-methyltransferases. 8-Hydroxy[Me-14C]bergapten was converted with a high degree of incorporation to isopimpinellin by Ruta cells in vivo, and it is suggested that the preference for the pathway via xanthotoxin may be due to more rapid hydroxylation of this substrate.

scholarly journals Floral herbivory of an invasive slug on a native weed

2014 ◽  
Vol 50 (No. 3) ◽  
pp. 151-156 ◽  
Author(s):  
A. Honěk ◽  
Z. Martinková
Keyword(s):  
Czech Republic ◽  
Seed Dispersal ◽  
Taraxacum Officinale ◽  
Herbaceous Plants ◽  
Floral Herbivory ◽  
Arion Lusitanicus ◽  
Seedling Predation

Effects of floral herbivory (grazing flowers) by slugs on production and quality of seeds of herbaceous plants have been rarely quantified. We studied consequences of grazing by an invasive slug Arion lusitanicus (Mabille) for inflorescences of dandelion (Taraxacum officinale Weber ex Wiggers). In May 2008, a grassy site in Prague-Ruzyně (Czech Republic) was densely populated by dandelion inflorescences. Of the 40% of the flowers grazed by the slug, 70% died before seed dispersal and seed was eaten from 10% of the closed mature inflorescences. Viability of seeds from inflorescences that survived slug grazing was not affected. In addition to seedling predation, grazing of flowers may be an important source of dandelion mortality at sites where this slug is abundant.

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