Honeydew (secretion)

When their mouthpart penetrates the phloem, the sugary, high-pressure liquid is forced out of the anus of the insects, allowing them to rapidly process the large volume of sap required to extract essential nutrients present at low concentrations.

[4][5] The sap continues to bleed after the insects have moved on, leaving a white sugar crust called manna.

In Madagascar, some gecko species in the genera Phelsuma and Lygodactylus are known to approach flatid plant-hoppers on tree-trunks from below and induce them to excrete honeydew by head nodding behaviour.

[13] In Norse mythology, dew falls from the ash tree Yggdrasil to the earth, and according to the Prose Edda book Gylfaginning, "this is what people call honeydew and from it bees feed.

[citation needed] Honey-dew is referenced in the last lines of Samuel Coleridge's poem Kubla Khan, perhaps because of its mythological connotations: And all who heard should see them there, And all should cry, Beware!

Weave a circle round him thrice, And close your eyes with holy dread, For he on honey-dew hath fed, And drunk the milk of Paradise.

The honeydew producing insects preferred the Medjhool variety to the Deglet Noor in Israel, where they have been observed in the Arava Valley.

This injury can cause the tree to release a sweet honeydew, thought to attract wasps that can parasitize the weevil within its acorns.