Editing Aphid (section)

===Ant mutualism===
[[File:Ant guards its Aphids.jpg|thumb|An ant guards its aphids]]<!--a far sharper image-->
[[File:Myrmica puceron.jpg|thumb|upright=1.2|left|Ants tending aphids]]<!--Substituting less good image because of licensing issues mentioned at DYK-->
[[File:ant feeding on honeydew.JPG|thumb|Ant extracting honeydew from an aphid]]
[[File:Aphids and ants.webm|thumb|thumbtime=35|[[Ant]]s tending aphids and collecting [[Honeydew (secretion)|honeydew]] secreted. A [[Podabrus rugosulus|wrinkled solder beetle]] flies in and eats an aphid before being chased away by the ants.]]

Some species of [[ant]]s farm aphids, protecting them on the plants where they are feeding, and consuming the honeydew the aphids release from the [[Rectum|terminations]] of their [[Gastrointestinal tract|alimentary canals]]. This is a [[Mutualism (biology)|mutualistic relationship]], with these dairying ants milking the aphids by stroking them with their [[antenna (biology)|antennae]].{{efn|Dairying ants also milk [[mealybug]]s and other insects.}}<ref name="Hooper">{{cite encyclopedia |title=Ant |author=Hooper-Bui, Linda M. |encyclopedia=[[World Book Encyclopedia]] |year=2008 |isbn=978-0-7166-0108-1}}</ref> Although mutualistic, the feeding behaviour of aphids is altered by ant attendance. Aphids attended by ants tend to increase the production of honeydew in smaller drops with a greater concentration of amino acids.<ref>{{cite journal |last1=Stadler |first1=Bernhard |last2=Dixon |first2=Anthony F. G. |date=2005 |title=Ecology and Evolution of Aphid-Ant Interactions |journal=Annual Review of Ecology, Evolution, and Systematics |volume=36 |issue=1 |pages=345–372 |doi=10.1146/annurev.ecolsys.36.091704.175531}}</ref>

Some farming ant species gather and store the aphid eggs in their nests over the winter. In the spring, the ants carry the newly hatched aphids back to the plants. Some species of dairying ants (such as the European [[yellow meadow ant]], ''Lasius flavus'')<ref name="wootton">{{cite book |title=Insects of the World |author=Wootton, Anthony |publisher=[[Blandford]] |year=1998 |isbn=978-0-7137-2366-3 |url=https://archive.org/details/insectsofworld00woot_0 }}</ref> manage large herds of aphids that feed on roots of plants in the ant colony. Queens leaving to start a new colony take an aphid egg to found a new herd of underground aphids in the new colony. These farming ants protect the aphids by fighting off aphid predators.<ref name=Hooper/> Some [[bee]]s in [[coniferous forest]]s collect aphid honeydew to make [[Honey#Honeydew honey|forest honey]].<ref name=Stroyan/>

An interesting variation in ant–aphid relationships involves [[Lycaenidae|lycaenid butterflies]] and ''[[Myrmica]]'' ants. For example, ''[[Niphanda fusca]]'' butterflies lay eggs on plants where ants tend herds of aphids. The eggs hatch as [[caterpillar]]s which feed on the aphids. The ants do not defend the aphids from the caterpillars, since the caterpillars produce a [[pheromone]] which deceives the ants into treating them like ants, and carrying the caterpillars into their nest. Once there, the ants feed the caterpillars, which in return produce honeydew for the ants. When the caterpillars reach full size, they crawl to the colony entrance and form [[Cocoon (silk)|cocoon]]s. After two weeks, the adult butterflies emerge and take flight. At this point, the ants attack the butterflies, but the butterflies have a sticky wool-like substance on their wings that disables the ants' jaws, allowing the butterflies to fly away without being harmed.<ref name="I&S">{{cite book |title=Insects and Spiders |last=Neary |first=John |year=1977 |publisher=Time-Life Books |isbn=978-0-8094-9687-7 |pages=[https://archive.org/details/insectsspiders00time/page/78 78–79] |url=https://archive.org/details/insectsspiders00time/page/78 }}</ref>

Another [[ant mimicry|ant-mimicking]] gall aphid, ''[[Paracletus cimiciformis]]'' (Eriosomatinae), has evolved a complex double strategy involving two morphs of the same clone and ''[[Tetramorium]]'' ants. Aphids of the round morph cause the ants to farm them, as with many other aphids. The flat morph aphids are [[aggressive mimicry|aggressive mimics]] with a "[[wolf in sheep's clothing]]" strategy: they have hydrocarbons in their cuticle that mimic those of the ants, and the ants carry them into the brood chamber of the ants' nest and raise them like ant larvae. Once there, the flat morph aphids behave like predators, drinking the body fluids of ant larvae.<ref name="SalazarFürstenau2015">{{cite journal |last1=Salazar |first1=Adrián |last2=Fürstenau |first2=Benjamin |last3=Quero |first3=Carmen |last4=Pérez-Hidalgo |first4=Nicolás |last5=Carazo |first5=Pau |last6=Font |first6=Enrique |last7=Martínez-Torres |first7=David |title=Aggressive mimicry coexists with mutualism in an aphid |journal=Proceedings of the National Academy of Sciences |volume=112 |issue=4 |year=2015 |pages=1101–1106 |doi=10.1073/pnas.1414061112|pmid=25583474 |pmc=4313836 |bibcode=2015PNAS..112.1101S |doi-access=free }}</ref>