Nectar drinkers must feed quickly and efficiently due to the threat of predation. While the sweetest nectar offers the greatest energetic rewards, the sharp increase of viscosity with sugar concentration makes it the most difficult to transport. We here demonstrate that the sugar concentration that optimizes energy transport depends exclusively on the drinking technique employed. We identify th...

Many plant species grow extrafloral nectaries and produce nectar to attract carnivore arthropods as defenders against herbivores. Two nectary types that evolved with Populus trichocarpa (Ptr) and Populus tremula × Populus tremuloides (Ptt) were studied from their ecology down to the genes and molecules. Both nectary types strongly differ in morphology, nectar composition and mode of secretion, ...

PREMISE OF THE STUDY Understanding floral resources is vital for restoring pollinators in habitats affected by anthropogenic development and climate change. As the primary adult food, nectar can limit butterfly longevity and reproduction. For pollinator restoration, it would therefore be useful to examine nectar resources. However, because many flowers preferred by butterflies are too small for...

Through their effects on physicochemical features of floral nectar, nectar-dwelling yeasts can alter pollinator behavior, but the effect of such changes on pollination success and plant reproduction is unknown. We present results of experiments testing the effects of nectar yeasts on foraging patterns of captive and free-ranging bumble bees, and also on pollination success and fecundity of the ...

The genetic and evolutionary relationships among floral nectar-dwelling Pseudomonas 'sensu stricto' isolates associated to South African and Mediterranean plants were investigated by multilocus sequence analysis (MLSA) of four core housekeeping genes (rrs, gyrB, rpoB and rpoD). A total of 35 different sequence types were found for the 38 nectar bacterial isolates characterised. Phylogenetic ana...

BACKGROUND AND AIMS Several members of Bromeliaceae show adaptations for hummingbird pollination in the Neotropics; however, the relationships between floral structure, nectar production, pollination and pollinators are poorly understood. The main goal of this study was to analyse the functional aspects of nectar secretion related to interaction with pollinators by evaluating floral biology, ce...

For decades, linden trees (basswoods or lime trees), and particularly silver linden (Tilia tomentosa), have been linked to mass bee deaths. This phenomenon is often attributed to the purported occurrence of the carbohydrate mannose, which is toxic to bees, in Tilia nectar. In this review, however, we conclude that from existing literature there is no experimental evidence for toxicity to bees i...

Traits that are attractive to mutualists may also attract antagonists, resulting in conflicting selection pressures. Here we develop the idea that increased floral nectar production can, in some cases, increase herbivory. In these situations, selection for increased nectar production to attract pollinators may be constrained by a linked cost of herbivore attraction. In support of this hypothesi...

Nectar contains water, sugars and amino acids to attract pollinators and defenders and is protected from nectar robbers and microorganisms by secondary compounds and antimicrobial proteins. Floral and extrafloral nectar secretion can be induced by jasmonic acid, it is often adjusted to consumer identity and consumption rate and depends on invertase activity. Invertases are likely to play at lea...

Oilseed rape (OSR; Brassica napus L.) is a major crop in temperate regions and provides an important source of nutrition to many of the yield-enhancing insect flower visitors that consume floral nectar. The manipulation of mechanisms that control various crop plant traits for the benefit of pollinators has been suggested in the bid to increase food security, but little is known about inherent f...