Did you know endangered Karner blue butterflies are protected not just by people, but by ants, too?
Ants affect us all in one way or another, but some species of plants and animals communicate with and depend on ants directly. The Karner blue is one of these. Although Karners are capable of completing their life cycles without help from ants, scientists have shown that ants are able to protect the caterpillars from attacks by predators (Savignano, 1994). Fewer attacks on larvae means more Karners reaching adulthood to lay eggs.
Now, if you’re imagining that ants protect Karner caterpillars out of the goodness of their little ant hearts, think again. The caterpillars pay the ants for their service with a tasty (at least to an ant) secretion produced by a gland on the caterpillars’ backs. Of course, this system does not always work perfectly, and the caterpillars are occasionally attacked by the very ants that are normally their protectors.
There is much still to be learned about the relationships between ants and Karner caterpillars, but data collection is tricky because Karner larvae are elusive. They are well camouflaged and tiny, making them difficult to spot. Another part of the challenge is that there are literally hundreds of variables that could come into play and affect the way ants and Karners interact. A major variable is the species of ant. With over 50 species of ants in the Albany Pine Bush Preserve, researchers who wish to understand how different types of ants affect these caterpillars have their work cut out for them. For now, we will keep our eyes open and our notebooks close at hand, because, with the Albany Pine Bush Karner populations on the rise, opportunities to observe this fascinating interaction between two very cool creatures are increasingly common.
To see a video recorded at the Albany Pine Bush this week of Tapinoma sessile (the Odorous House Ant) tending a Karner blue butterfly larvae, follow this link.
Savignano, D.A. (1994) Benefits to Karner blue butterfly larvae from association with ants. Karner Blue Butterfly: a Symbol of a Vanishing Landscape (ed. by D. A. Andow, R. J. Baker and C. P. Lane), pp. 37–46. University of Minnesota Agricultural Experiment Station, St Paul, Minnesota.