Floral nectar contains mainly sugars but also amino acids, organic acids, inorganic ions and secondary compounds to attract pollinators. The genus Nicotiana exhibits great diversity among species in floral morphology, flowering time, nectar compositions, and predominant pollinators. We studied nectar samples of 20 Nicotiana species, composed equally of day- and night-flowering plants and attrac...

Honeybees collect nectar from flowering plants in the environment to accommodate their energetic demands. In a honeybee colony a temporal caste, “foragers”, is collecting nectar. These foragers bring their harvest into the colony, where they unload their nectar loads to one or more specialised “storer bees”, another temporal caste in the colony, responsible for the next step of nectar processin...

Many herbivorous insects feed on plant tissues as larvae but use other resources as adults. Adult nectar feeding is an important component of the diet of many adult herbivores, but few studies have compared adult and larval feeding for broad groups of insects. We compiled a data set of larval host use and adult nectar sources for 995 butterfly and moth species (Lepidoptera) in central Europe. U...

Many zoophilous plants attract their pollinators by offering nectar as a reward. In gynodioecious plants (i.e. populations are composed of female and hermaphrodite individuals) nectar production has been repeatedly reported to be larger in hermaphrodite compared to female flowers even though nectar production across the different floral phases in dichogamous plants (i.e. plants with time separa...

Inga species present brush-type flower morphology allowing them to be visited by distinct groups of pollinators. Nectar features in relation to the main pollinators have seldom been studied in this genus. To test the hypothesis of floral adaptation to both diurnal and nocturnal pollinators, we studied the pollination ecology of Inga sessilis, with emphasis on the nectar secretion patterns, effe...

In southern England, Linaria vulgaris (common yellow toadflax) suffers from high rates of nectar robbery by bumblebees. In a wild population of L. vulgaris we found that 96 % of open flowers were robbed. Five species of bumblebee were observed foraging on these flowers, although short-tongued species (Bombus lapidarius, B. lucorum and B. terrestris) robbed nectar whilst longer-tongued ones beha...

Floral nectar of animal-pollinated plants is commonly infested with microorganisms, yet little is known about the microorganisms inhabiting the floral nectar of orchids. In this study, we investigated microbial communities occurring in the floral nectar of seven Epipactis (Orchidaceae) species. Culturable bacteria and yeasts were isolated and identified by partially sequencing the small subunit...

Nachev et al (Reports, 6 January 2017, p. 75) present dilute nectar in bat-pollinated plants as "paradoxical" because bats prefer concentrated nectar, but paradox disappears with realistic assumptions about nectar evolution. We argue that they make unrealistic assumptions about the cognitive abilities of bat pollinators, invoke Weber's law inappropriately, and cannot predict observed nectar con...

Many previous studies report nectar residues being consistently lower than pollen residues in the same plant species. This is also evident in our samples from the oilseed rape (OSR) crop, where 100% of pollen samples contained thiamethoxam, whereas only 53.9% of the nectar samples had detectable levels of this compound. However, as clearly explained in our manuscript, our wildflower nectar and ...

Nectar is a primary nutrient reward for a variety of pollinators. Recent studies have demonstrated that nectar also has defensive functions against microbial invasion. In this study, the Liriodendron tulipifera nectary was first examined by scanning electron microscopy, and then the nectar was analyzed by two-dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometry, wh...