Ant men who really love their mother

This half-century-old song by Tom Lehrer seems—save for its failure to mention ants—to anticipate a study published this month about ants:

ChrissiVirgin ant queens mate with their own sons to avoid failure at colony foundation,” Christine Vanessa Schmidt [pictured here], Sabine Frohschammer, Alexandra Schrempf, Jürgen Heinze, Naturwissenschaften, vol. 101, no. 1, January 2014, pp 69-72. (Thanks to investigator Tom Gill for bringing this to our attention.) The authors, at Universität Regensburg, Germany, explain:

“Mother–son mating (oedipal mating) is practically non-existent in social Hymenoptera, as queens typically avoid inbreeding, mate only early in life and do not mate again after having begun to lay eggs. In the ant genus Cardiocondyla mating occurs among sib in the natal nests. Sex ratios are extremely female-biased and young queens face the risk of remaining without mating partners. Here, we show that virgin queens of Cardiocondyla argyrotricha produce sons from their own unfertilized eggs and later mate with them to produce female offspring from fertilized eggs. Oedipal mating may allow C. argyrotricha queens to found new colonies when no mating partners are available and thus maintains their unusual life history combining monogyny, mating in the nest, and low male production.”