Cryptopone sauteri

One of the most common ant species in temperate Japan.

Identification
Worker. Total length of workers around 3.5 - 4 mm. Color yellow to yellowish brown. Body covered thickly with golden hairs. Mandibles with 9 or 10 teeth. Dorsal outline of clypeus gently sloping in lateral view. Subpetiolar process developed, subtriangular and with an angled ventral tip.

Distribution based on Regional Taxon Lists
Palaearctic Region: China, Democratic Peoples Republic of Korea, Japan, Republic of Korea.

Biology
This species nests in rotting wood and leaf litter in forests. Colony size is relatively large compared to other Korean ponerine ants.

Yamaguchi et al. (2017) studied life history details of this species in Niigata Prefecture, Japan. The area (37 05´N, 138 37´E) was a mixed deciduous and coniferous forest. Winters snowfall and cold temperatures restrict ant activity to the warmer months of the year. Dead branches, where C. sauteri nest were collected every two weeks between May and November in 2008 and 2009, and their demographic attributes recorded.

Sixty percent of the 331 nests found were queenless, with the number of mated queens, when present, increasing into the fall. This suggests seasonal polydomy. Unmated queens were also present, and relatively abundant, but did not change in number with time of year.

Alates were present in August and September, which suggests fall mating flights. All queens were winged. Worker numbers increased in the fall, suggesting workers and sexuals were produced together. Larvae were collected throughout the year but decreased toward the fall. Pupae were found between July and September. This suggests workers and alates emerge just once a year. Eggs were found only during three nest collection periods. Egg laying by queens was not determined but mated queens with a developed ovary were collected between May and November (Yamaguchi et al., 2016), suggesting that they lay eggs over the months.

Nomenclature

 *  sauteri. Pachycondyla (Pseudoponera) sauteri Wheeler, W.M. 1906c: 304, pl. 41, fig. 6 (w.q.) JAPAN. Ogata, 1987: 118 (m.); Imai & Kubota, 1972: 194 (k.). Combination in Euponera (Pseudoponera): Emery, 1909c: 365; in Euponera (Trachymesopus): Teranishi, 1940: 8; in Cryptopone: Brown, 1963: 6; in Pachycondyla: Mackay & Mackay, 2010: 3 (by implication as Cryptopone synonymised with Pachycondyla); in Cryptopone: Schmidt & Shattuck, 2014: 185.