Plants are dependent on exogenous nitrogen (N) supply. Ammonium (NH₄(+)), together with nitrate (NO₃(-)), is one of the main nitrogenous compounds available in the soil. Paradoxically, although NH4 (+) assimilation requires less energy than that of NO₃(-), many plants display toxicity symptoms when grown with NH₄(+) as the sole N source. However, in addition to species-specific ammonium toxicit...

Both rewards and signals are important in mutualisms. In myrmecochory, or seed dispersal by ants, the benefits to plants are relatively well studied, but less is known about why ants pick up and move seeds. We examined seed dispersal by the ant Aphaenogaster rudis of four co-occurring species of plants, and tested whether morphology, chemical signaling, or the nutritional quality of fatty seed ...

Samples of sorghum distillers dried grains with solubles (DDGS) were collected and analyzed to establish a nutrient database and evaluate the quality and consistency between and within 5 ethanol plants in Kansas and Texas. Each sample (n = 21) was analyzed for AA, DM, CP, crude fiber, crude fat, ash, NDF, ADF, trace minerals, and starch. Mean values (DM basis) were 0.88% Lys, 10.49% crude fat, ...

The objective of these studies was to assess the degree to which bean leaf beetle, Cerotoma trifurcata (Forster), will feed on cucurbits. In 2003, we documented an infestation of C. trifurcata in a commercial pumpkin field near Rosemount, MN, USA. To evaluate C. trifurcata feeding on cucurbits, we conducted laboratory no-choice and choice test feeding studies. In the laboratory, C. trifurcata f...

BACKGROUND AND AIMS Cost-benefit models predict that carnivory can increase the rate of photosynthesis (A(N)) by leaves of carnivorous plants as a result of increased nitrogen absorption from prey. However, the cost of carnivory includes decreased A(N) and increased respiration rates (R(D)) of trapping organs. The principal aim of the present study was to assess the costs and benefits of carniv...

ABSTRACT- Elm leaf beetle (ELB), Xanthoga leruca luteola (Muller), is considered as one of the most important and destructive phytophagous pests of Ulmus species in the north of Iran. In the current study, the effects of three host plants including Ulmus carpinifolia, U. carpinifolia var. umbraculifera, and Zelkova carpinifolia, on feeding indices and biochemical processes of ELB were examined ...

The foraging behaviour, diet and habitat use of North Island kokako (Callaeas cinerea wilsoni) were studied in Puketi State Forest from October 1981 to August 1982. Kokako fed mainly from branches and twigs of canopy and upper-understorey plants. Although 68 different foods were eaten, only eight contributed more than 5% to the observed diet in any season. The diet consisted of fruit (44%), unk...

Cotton plants induce high levels of gossypol in response to herbivore damage. However, little is known about the mechanisms by which insect herbivory modulates gossypol biosynthesis in cotton plants. Here, we report the mechanism by which herbivore damage or insect-originated elicitors modulate the biosynthesis of gossypol and jasmonic acid (JA) in plants. Spodoptera exigua larval-damaged (HD) ...

Sequestration of chemical defenses from host plants is a strategy widely used by herbivorous insects to avoid predation. Larvae of the arctiine moth Utetheisa ornatrix feeding on unripe seeds and leaves of many species of Crotalaria (Leguminosae) sequester N-oxides of pyrrolizidine alkaloids (PAs) from these host plants, and transfer them to adults through the pupal stage. PAs confer protection...

Despite the widespread use of urease inhibitors in agriculture, little information is available on their effect on nitrogen (N) uptake and assimilation. Aim of this work was to study, at physiological and transcriptional level, the effects of N-(n-butyl) thiophosphoric triamide (NBPT) on urea nutrition in hydroponically grown maize plants. Presence of NBPT in the nutrient solution limited the c...