**Group 1: Nectar Basics**
– Etymology: Nectar originates from Greek ‘νεκταρ,’ associated with the drink of eternal life or immortality.
– Common use: The term nectar was first recorded in AD 1600 to refer to the sweet liquid in flowers.
**Group 2: Floral Nectaries**
– Types: Nectaries are found in various parts of flowers like receptacles, stamens, pistils, etc.
– Function: Nectaries secrete nectar to attract pollinators such as insects, bees, moths, and vertebrates.
– Importance: Nectar serves as a reward for pollinators that protect plants from predators.
**Group 3: Nectar Secretion**
– Factors: Nectar secretion increases with pollinator visits and varies based on flower age and habitat.
– Process: Nectar is reabsorbed by the plant after pollination.
**Group 4: Extrafloral Nectaries**
– Definition: Extrafloral nectaries are not involved in pollination and are found on leaves or petioles.
– Diversity: They vary in form, location, size, and mechanism and are present in various plant parts like stipules, cotyledons, and fruits.
**Group 5: Nectar Composition and Importance**
– Components: Nectar contains sugars like sucrose, glucose, and fructose, along with phytochemicals to attract pollinators and deter predators.
– Importance: Nectar is economically important for honey production, used in agriculture, and plays a significant role in the evolution of nectar-eating species.
Nectar is a sugar-rich liquid produced by plants in glands called nectaries or nectarines, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide herbivore protection. Common nectar-consuming pollinators include mosquitoes, hoverflies, wasps, bees, butterflies and moths, hummingbirds, honeyeaters and bats. Nectar plays a crucial role in the foraging economics and evolution of nectar-eating species; for example, nectar foraging behavior is largely responsible for the divergent evolution of the African honey bee, A. m. scutellata and the western honey bee.[citation needed]
Nectar is an economically important substance as it is the sugar source for honey. It is also useful in agriculture and horticulture because the adult stages of some predatory insects feed on nectar. For example, a number of predacious or parasitoid wasps (e.g., the social wasp species Apoica flavissima) rely on nectar as a primary food source. In turn, these wasps then hunt agricultural pest insects as food for their young.
Nectar is most often associated with flowering plants angiosperms, but it is also produced by other groups, including ferns.