Nectar is a sweet 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. Nectaries can be located on any plant, but they are most common in the flowers of a plant. Nectar is mainly a watery solution of the sugars fructose, glucose, and sucrose but also contains traces of proteins, salts, acids, and essential oils. Nectars range in sweetness from as little as 8% to as high as 50% .
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 parasitoid wasps rely on nectar as a primary food source. In turn, these wasps then hunt agricultural pest insects as food for their young.
There are two types of nectar: floral nectar and extra-floral nectar. Floral nectar is presented inside the flower close to the reproductive organs and rewards animals that perform pollination while visiting the flower. Extra-floral nectar is involved in so-called indirect defense by attracting animals (generally ants) that prey on herbivores, or by discouraging herbivores from feeding on the plant.
Fun fact: Bees use nectar to make honey – it is the basic material used to make it.
