Philidris nagasau

Philidris nagasau is polydomous. It cultivates and manages large Squamellaria colonies by collecting and planting the plants’ seeds under tree bark and fertilising its crop from the seedling stage onward. The ants feed on sugar- and amino-acid-rich floral food rewards produced by mature Squamellaria plants (Chomicki and Renner 2016; Chomicki et al. 2016, Chomicki and Renner 2019). The ants obligately use the domatia of this plant for their nests.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Fiji.

Biology
Chomicki and Renner (2019) studied nutrient uptake in ephipytic plants in the genus Squamellaria. Seeds of this plant are placed under bark by P. nagasau, and the ants obligately use the ephiphyte, which forms a domatia, for their nests. This study showed that nutrient uptake was greatly enhanced by the ants, putatively through the ants defecating on absorptive warts found on the inside walls of the domatia. The warts are thought to be analogous to root hairs in their capacity and function.

Nomenclature

 *  nagasau. Iridomyrmex nagasau Mann, 1921: 470, fig. 27 (w.) FIJI IS. Combination in Philidris: Shattuck, 1992a: 18. Senior synonym of agnatus, alticola: Sarnat & Economo, 2012: 36.
 * agnatus. Iridomyrmex nagasau subsp. agnatus Mann, 1921: 472 (w.) FIJI IS. Combination in Philidris: Shattuck, 1992a: 18. Junior synonym of nagasau: Sarnat & Economo, 2012: 36.
 * alticola. Iridomyrmex nagasau subsp. alticola Mann, 1921: 472 (w.) FIJI IS. Combination in Philidris: Shattuck, 1992a: 18. Junior synonym of nagasau: Sarnat & Economo, 2012: 36.