honeydew

An aphid produces honeydew for an ant in an example of mutualistic symbiosis. Honeydew drops on leaves Bald-faced hornet sips honeydew from a Disholcaspis quercusmamma gall covered by sooty mold Magicicada cassini "cicada rain" slow motion Milkweed aphids on narrow-leaf milkweed eliminating honeydew. Unlike some aphids, these kick the drop away with their leg.

Honeydew is a sugar-rich sticky liquid that is secreted by aphids, some scale insects, many other true bugs, and some other insects as they feed on plant sap. 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. Honeydew is particularly common as a secretion in hemipteran insects and is often the basis for trophobiosis. Some caterpillars of Lycaenidae butterflies and some moths also produce honeydew. In addition to various sugars, honeydew contains small amounts of amino acids, other organic compounds, and inorganic salts, with its precise makeup affected by factors such as insect species, host plant species, and whether a symbiotic organism is present.