Johnson, C., Agosti, D., Delabie, J.H.C., Dumbert, K., Williams, D.J., Von Tschirnhaus, M., & Maschwitz, U. 2001 Acropyga and Azteca ants (Hymenoptera: Formicidae) with scale insect (Sternorrhyncha: Coccoidea): 20 million years of intimate symbiosis.. American Museum Novitates (New York) No. 3335: 18 pp.

Notes: Species of the genus Acropyga are rarely encountered subterranean ants that rely on mealybugs or aphids to provide their nutritional needs. Female Acropyga (Formicinae) alates of pantropical and Mediterranean species carry mealybugs with their mandibles while swarming and probably inoculate their new nests with these mealybugs. The natural history of Acropyga and other mealybug-tending ant species, a summary of the various reports of Acropyga and other mealybugs, and a new record from French Guiana are presented here. Also provided are a first report and description of Acropyga alates with mealybugs in Dominican amber dated to the Miocene, a discovery indicating that this intimate association and relatively uncommon behavior has existed for at least 15-20 million years. The mealybugs found with the Acropyga females in amber are related to the hypogaeic genera Eumyrmococcus Silvestri and Neochavesia Williams & Granara de Willink (Pseudococcidae, Rhizoecinae) and represent three new species of a new genus. The genus Electromyrmococcus and the species Electromyrmococcus abductus Williams, Electromyrmococcus inclusus Williams and Agosti, and Electromyrmococcus reginae Williams are described. A piece of Dominican amber containing workers of Azteca alpha Wilson (Dolichoderinae) and 23 scale insects is also presented and the significance of these specimens in Dominican amber is discussed.