Altruistic Aphids, an Evolutionary Anomaly by Brian Thomas, M.S.
* Certain aphids manipulate plant tissues to form a hollow gall
in which they then reside. But aphids will also help heal plant
tissue that they’ve damaged. This behavior serves as a vital
self-defense mechanism, because when the gall’s walls are eaten
by caterpillars, the tender aphids inside become easy prey for
other insect predators. Evolutionary biologist Takema Fukatsu of
the National Institute of Advanced Industrial Science and
Technology in Tsukuba, Japan, found that specialized aphid
guards extrude their body contents to fill holes in the plant
wall, “kneading their own gooey blood into a big scab.”1 Many of
these types of aphids, named Nipponaphis monzeni, die in the
process. In a recently-published study, the research team
examined gall walls in various stages of repair and found that
the aphid-made scab played the same role as animal-skin scabs,
serving as templates for body tissue to grow over the area and
repair the wound.2 Moreove