More on collaboration

Awhile ago I asked Art Weis, the Director here, if he knew of examples of collaboration in the plant world, between plants, say, or perhaps between a plant and some other creature. His immediate response was no … but then he paused and thought and said something about mutualism …  a term I have to explore. 

But in the meantime I’ve been reading Forests of Ash by Tom Griffiths, an environmental history of the mountain ash (Eucalyptus regnans) forests in the Australian state of Victoria. The book is excellent, readable and intelligent; it explores the shifting understandings of the forest as well as the forest itself. 

E. regnans is the tallest hardwood in the world, a magnificent tree. This image from Wikipedia will give you an idea of its size:

But to get back to collaboration, in Griffiths's book I came across a description (by entomologist Ross Field) of the complex relationships among a butterfly, two kinds of trees, and a species of ant. The butterfly is the Silky Hairstreak (Pseudalmenus chlorinda zephyrus) that breeds and feeds on various wattles (acacias). It looks like this (another Wikipedia image):

            “This small, beautiful butterfly with delicate tails, lays its eggs on wattle stems, but only on those that have [colonies of small black ants, Anonychomyrma biconvexa] nearby. Usually these ants are attending sap-sucking bugs, milking them of honey dew. The ants soon focus their attention on the young butterfly caterpillars that hatch from the eggs. The ants swarm over the larvae, tending posterior glands that exude protein-rich sugars.

[The ant looks like this: http://eol.org/pages/474085/overview]

            “The ants tend the caterpillars throughout their growth, usually from November to January [remember, this is Australia and summer time]. When mature, the caterpillars seek shelter to pupate. This begins with an extraordinary journey. Down the wattle tree the mature caterpillars travel, following the trail of ants, and up and under the bark of an adjoining eucalytus tree, more often than not a mountain ash. Here the caterpillars pupate, often clustered together, spending the next eight to ten months securely adhering to the trunk of the tree, and receiving occasional visits from the ants.

            “Such an amazing symbiotic relationship between ants and butterfly is thought to provide the caterpillars with some protection from marauding predators such as spiders and bugs and parasitic flies and wasps. … [The ants] do not need the butterfly to survive [but]… the Hairstreak cannot exist without attendant colonies of this one species of ant.”      (Forests of Ash, p. [112])

Because I’m interested in the metaphorical uses and reach of words I find myself thinking of this relationship among butterfly, ants, and trees as a kind of collaboration. I suspect—but don’t know—that most scientists would not accept the word as accurate, applied here.