Ants manipulate aphid reproduction, because they want snacks
Hi guys, today I want to share a research I came across recently. It is about ants and their manipulation of aphid reproduction. It is quite short, so will not take long time to read! ;)
Intrigued? Read on!
As you probably know (or maybe even seen) some species of ants form a symbiotic relationship with aphids. Aphids are small insects that feed on plants and produce sweet substance termed honeydew. Ants enjoy consuming honeydew and thus protect aphids from predators such as wasps or ladybugs. They also transport the aphids when needed. You can compare this relationship to farmer and cow. Farmer protects and cares for cow and cow provides him with milk.
Source
In one species of aphids (Macrosiphoniella yomogicola) there are two polymorphisms – red and green. What is polymorphism? Well, it is a variation of certain physical trait – such as colour of the body in this case. However, there is probably more to it than just mere colour change, because ants (specifically Lasius japonicus) prefer honeydew from green-coloured variant. It probably tastes better!
Two polymorphisms - green and red.
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Under normal circumstances red-variant aphids have superior reproductive capabilities and thus dominate the population. However, introduction of ants into this system results in equalization of reproduction rates of both species.
Now now, you should form a question in your minds. If there is a preference towards green-coloured variant of aphids, why keeping around the red-variant? Because even though the reproduction more or less equalizes, the red variant still reproduces and is kept around. Why??? The answer: We do not know!
However, one of the authors has a theory:
"We theorize that the red morphs are able to provide a benefit that the green morphs can't, such as suppressing the development of lower buds on host plants. This might help both the red and green aphids survive and reproduce throughout more of the year, which could maximize long-term harvest of honey-dew from the green aphids. In this case, the ants invest in a future benefit by sacrificing the present benefit"
So, guys, thank you for reading my article and have a nice day!
Reference
Ants: Master manipulators for biodiversity, or sweet treats – Article on ScienceDaily
Ants improve the reproduction of inferior morphs to maintain a polymorphism in symbiont aphids – Original article
Other sources are directly in the text