ID guide | introduced ants

Pheidole noda

General description: 

The following account is from Sarnat et al. (2015) and figure numbers refer to that publication.

Pheidole noda is a large, long-limbed, dark colored species most easily recognized by its distinctly enlarged dome-like postpetiole. The species belongs to a clade of large-bodied species that has diversified across Indomalaya (Economo et al. 2015). Although both P. noda and P. megacephala are considered to have an enlarged postpetiole, they are very different in shape. That of the former is dome-like (Fig. 2) and that of the latter has an anteroventral bulge in addition to the posterodorsal bulge (Fig. 1). The majors of P. noda are easily separated from those of P. megacephala by the strongly sculptured face (Fig. 8 vs. Fig. 9). The minors both have glossy faces, but those of P. noda are larger with relatively longer antennal scapes (Fig. 39 vs. Fig. 40). Pheidole noda is occasionally confused with other Asian tramp Pheidole, including P. fervens and P. indica, but both major and minor workers are easily separated from these by the enlarged postpetiole. Readers are referred to Eguchi (2008) for characters used to separate P. noda from its other Asian congeners.


Despite being a relatively common species across its native range, little is known about the biology of P. noda. The species is apparently easy to keep in laboratory settings, and Yamamoto et al. (2009) reported that they kept a colony with five dealated queens, suggesting dependent colony foundation or polygyny. The authors also noted that in Japan it nests in the ground but also forages in vegetation. Pheidole noda was the most frequent visitor to extrafloral nectaries of Mallotus japonicus in an experiment conducted in Japan (Yamawo et al. 2012). Eguchi (2008) observed that P. noda occurs from open lands to relatively developed forests, and nests in the soil, under shelters on the ground, and in rotting logs. Eguchi (2004a) noted that the species takes seeds of sesame and amaranth put on the ground, and majors serve as repletes. During a recent survey in Yunnan, China, the species was found to occur in rubber tree plantations and rainforest between 550­ and 1219 m (Liu et al. 2015). 

Risk statement: 

Pheidole noda is not considered an agricultural, ecological or structural pest species, although it is often associated with disturbed habitats. The species is also not known to have established outdoors beyond its native range. However, perhaps because it can be easily maintained in artificial nests, colonies with laying queens listed as Pheidole noda and Pheidole cf. noda are available for sale from businesses advertising on the internet. The shipment of this species outside its native range to hobbyists increases its chances of accidental release into non-native habitats. 

Diagnostic description: 

Diagnosis among introduced Pheidole. Medium to dark reddish brown. Major | HW 1.58–1.82, HL 1.69–1.91, SL 1.00–1.12, CI 93–98, SI 56–65 (n=5, Eguchi 2008). Head subquadrate (Fig. 7). Head rugoreticulate on posterolateral lobes and laterad of frontal carinae (Fig. 13a), but frons dominated by long, well-organized and parallel longitudinal rugae (Fig. 13b). Antennal scrobes indistinct to moderately impressed, but frontal carinae always forming a border capable of accepting the antennal scape (Fig. 13c). Promesonotum in profile with two convexities (Fig. 5), the large anterior dome in addition to a distinct mound or prominence on the posterior slope. Postpetiole forming a high dorsally bulging dome that is tallest at midpoint (Fig. 2a); ventral margin flat to very weakly convex (Fig. 2b). Minor | HW 0.57–0.66, HL 0.71–0.82, SL 0.91–1.07, CI 80–82, SI 157–162 (n=5, Eguchi 2008). Head predominantly glossy (Fig. 36), lacking punctation and or rugae above eye level. Posterior head margin strongly convex (Fig. 44). Antennal scapes long (e.g. Fig. 39), but not surpassing the posterior head margin by more than 2x eye length. Promesonotum in profile with two convexities, the large anterior dome (Fig. 43a) in addition to a distinct prominence on the posterior slope (Fig. 43b). Petiole and postpetiole glossy to very weakly sculptured laterally (Fig. 48). Postpetiole forming a high dorsally bulging dome that is tallest at midpoint; ventral margin flat to very weakly convex (Fig. 2).


Pheidole noda is considered native across mainland Asia, occurring from western India east to Japan. Forel (1903) reported the species from the Andaman Islands but it was not recovered during a more recent survey of the islands (Mohanraj et al. 2010). There is geographic disjunction between the mainland Asia population and the populations from the southern islands of Indonesia. The majors of the Indonesian taxon, originally described as Pheidole treubi Forel, were considered a distinct population by (Eguchi 2001b), but conspecific with P. noda. Although not included on the map, if verified, the records from the Russian Far East (Kupianskaia 1990) would be the most northern extent of the native range. The dispersive capacity of P. noda is demonstrated by its colonization of Volcano Island (Nishino-shima Island), which is 22 ha in size and located 1,000 km south of mainland Japan. The island erupted in 1973, virtually eradicating all life. Pheidole noda was the only ant species discovered during the 1983 survey, and was one of only two discovered during the 2004 survey (the other being Tetramorium bicarinatum).

The only confirmed record of P. noda occurring outside of its putative native range is from a glasshouse in Italy (Limonta and Colombo 2003), where it was found together with P. megacephala and Tetramorium bicarinatum on nursery plants imported from Asia. The species was also found on plant material imported from Asia and intercepted at quarantine facilities in Washington and Hawaii. 

Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith