Lasius nipponensis

This species is a temporary social parasite of Lasius species belonging to the subgenus Chthonolasius. In the Kanto district, Japan, it frequently tends aphids on trees (Kubota, 1988). Nuptial flights occur during June and July.

L. nipponensis was first recorded from Japan by Matsumura (1898). Thereafter, Japanese myrmecologists have consistently used the name Lasius fuliginosus for this relatively common ant. However, recent morphological and biochemical comparisons between European and East Asian populations imply that they represent separate species (Espadaler et al., 2001; Japanese Ant Image Database).

Identification
An eastern Asian species most readily distinguished by the aberrant pilosity and pubescence of the queen caste.

Radchenko (2005) - Workers: petiolar scale (seen in profile) thin, distinctly narrowing to the top and with flattened dorsal crest, symmetrical; seen in front or from behind, it is the widest at the level of the spiracles, clearly tapering to the top, its dorsal crest narrowly rounded, without notch; head in full face view distinctly narrowing anteriorly and with shallowly emarginate occipital margin; scape, mid and hind tibiae not flattened, elliptical in cross-section; ratio of min/max diameters of the scape > 0.7; scape and legs with numerous subdecumbent hairs; promesonotal dorsum and occipital margin with rather long standing hairs; body with sparse, short decumbent pubescence.

Queens: petiolar scale (seen in profile) thin, narrowing to the top; head in full face view distinctly narrowing anteriorly, with almost straight lateral margins in front of the eyes, and with hardly emarginate occipital margin; scape, mid and hind tibiae not flattened, elliptical in cross-section; ratio of min/max diameters of the scape > 0.7; legs and scape with dense decumbent pubescence and numerous subdecumbent hairs; head, alitrunk and gaster with very abundant, long, often curved standing hairs.

Distribution
Radchenko (2005) - Southern part of Russian Far East (Primorsky Region), Korean Peninsula, Japan (Hokkaido, Honshu, Shikoku), Taiwan.

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

Nomenclature

 *  nipponensis. Lasius fuliginosus var. nipponensis Forel, 1912l: 339 (w.q.) JAPAN. Junior synonym of fuliginosus: Wilson, 1955a: 138; Yamauchi, 1979: 171. Revived from synonymy and raised to species: Espadaler, Akino & Terayama, 2002: 340. Senior synonym of crispus Wilson: Radchenko, 2005a: 84.
 * crispus. Lasius (Dendrolasius) crispus Wilson, 1955a: 144 (w.q.m.) JAPAN. [Unresolved junior primary homonym of crispus Théobald, above.] Junior synonym of capitatus: Kupyanskaya, 1989: 785; of nipponensis: Radchenko, 2005a: 84. See also: Yamauchi, 1979: 174.

Worker
Radchenko (2005) - HL1 = 1.09-1.25, HL2 = 1.15-1.30, HW1 = 1.09-1.26, HW2= 0.67-0.76, SL = 1.01-1.18, OL = 0.23-0.25, AL = 1.26-1.51; CI = 1.00-1.01, CLI = 1.04-1.05, CWI = 1.63-1.67, SI1 = 0.92-0.94, SI2 = 0.92-0.94, OI = 0.20-0.21.

Wilson (1955) – description of synonym Lasius crispus: Two workers from Ueda, Honshu, and a small series from central Korea are tentatively and with great reservation placed in this species and used for the following diagnosis.

(1) The standing hairs of the second and third gastric tergites, anterior to the extreme posterior strips, as long as those of the pronotum or longer. In the Ueda series but not in the Korean series, femora with numerous outstanding decumbent to suberect hairs. Cephalic and gastric pilosity denser than in fuliginosus.

(2) Petiolar crest viewed from the side thinner and sharper than in fuliginosus, the anterior and posterior faces less convex (Pl. 2, Fig. 8).

PW of Ueda workers 0.64 and 0.72 mm., of Korean series 0.77-0.87 mm.

Queen
Wilson (1955) – description of synonym Lasius crispus: 1) Body and appendage hairs much finer than in fuliginosus, many curved at the tip or even sinuate. On the appendages, where the pilosity is predominantly decumbent to subdecumbent, the hairs are frequently wicket-shaped in addition, recurving to touch the cuticular surface with their tips.

(2) Body pubescence very sparse or absent, so that the entire cuticular surface is moderately to strongly shining. The appendages are densely covered with appressed hair, the legs somewhat more so than the scapes.

(3) Viewed from the side the crest of the petiole thin and acute; the entire posterior margin of the petiole feebly concave in each of the three specimens examined.

(4) Viewed in full face the genal margins nearly straight, curving inward only near the mandibular insertions. As a result the occipital region appears proportionately wider, and the entire head more sagittate, than in fuliginosus.

(5) The median clypeal keel, which is feebly developed in fuliginosus, is completely lacking in crispus.

HW of paratopotype 1.58 mm., of Ueda queen 1.55 mm., of Kochi City queen 1.52 mm.

Male
Wilson (1955) – description of synonym Lasius crispus: (1) In side view the anterior and posterior faces of the petiole taper equally to form a narrow, sharp crest. Otherwise very similar to fuliginosus.

(2) Terminal segments of maxillary palp highly variable in length as in other Dendrolasius, but showing no sign of ankylosis.

(3) Pygostyle and subgenital plate as in fuliginosus.

HW of paratopotype male 1.08 mm., of Ueda series 1.04-1.26 mm. Genitalia identical to that of fuliginosus.

References based on Global Ant Biodiversity Informatics

 * Choi B.M. 1985. Study on distribution of ants (Formicidae) from Korea (1). Formic fauna in Mt. Songni. Cheongju Sabom Taehak Nonmunjip (Journal of Cheongju National Teachers' College) 22:401-437.
 * Choi B.M. 1986. Studies on the distribution of ants (Formicidae) in Korea. Journal of Chongju National Teacher College 23: 317-386.
 * Choi B.M. 1996. Studies on the distribution of ants (Formicidae) in Korea (15) -Ant fauna islands Ullungdo and Dokdo. Journal of Chongju National University of Education 33: 201-219.
 * Choi B.M., Bang, J.R. 1992. Studies on the distribution of ants (Formicidae) in Korea (9). Ant fauna in Mt. Togyusan. Korean Journal of Applied Entomology 31:101-112.
 * Choi B.M., and J. R. Bang. Studies on the distribution of ants (Formicidae) in Korea (12): the analysis of ant communities in 23 islands. Journal of Cheongju National University of Education 30:317-330.
 * Collingwood C. A. 1976. Ants (Hymenoptera: Formicidae) from North Korea. Annales Historico-Naturales Musei Nationalis Hungarici 68:
 * Espadaler X., T. Akino, and M. Terayama. 2002. Taxonomic status of the ant Lasius nipponensis Forel, 1912 (Hymenoptera, Formicidae). Nouv. Rev. Entomol. 18: 335-341.
 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Ichinose K. 1990. The Ant Fauna of the Tomakomai Experiment Forest, Hokkaido University (Hymenoptera: Formicidae) with Notes on the Nuptial Season. Research Bulletins of College Experiment Forests 47(1) 137-144.
 * Kim B.J. 1996. Synonymic list and distribution of Formicidae (Hymenoptera) in Korea. Entomological Research Bulletin Supplement 169-196.
 * Li Z.h. 2006. List of Chinese Insects. Volume 4. Sun Yat-sen University Press
 * Maruyama M. 2005. The latest scientific names of the Japanese species of the subgenus Dendrolasius (genus Lasius), corresponding to their Japanese names. Ari 27: 25-27.
 * Maruyama M., F. M. Steiner, C. Stauffer, T. Akino, R. H. Crozier, and B. C. Schlick-Steiner. 2008. A DNA and morphology based phylogenetic framework of the ant genus Lasius with hypotheses for the evolution of social parasitism and fungiculture. BMC Evolutionary Biology 8:Article 237 (doi:10.1186/1471-2148-8-237).
 * Mizota K. 2002. A check list of insects in Kinkazan Island, Miyagi Pref., Northeastern Japan: A bibliographical Survey. Bulletin of Miyagi University of Education Environmental Education 5: 69-78.
 * Mizutani A. 1979. A myrmecofaunal survey at Hiyama Experiment Forest, Hokkaido University. Research Bulletin of the College Experiment Forests, Hokkaido University 36:509-516.
 * Paik W.H. 1984. A checklist of Formicidae (Hymenoptera) of Korea. Korean J. Plant Prot. 23(3): 193-195.
 * Park, Seong, Joon and Byung, and Kim, Jin. 2002. Faunal Comparison of Ants among Cheongsando and Other Islands of South Sea in Korea. Korean Jornal of Entomology. 32(1):7-12.
 * Radchenko A. 2005. A review of the ants of the genus Lasius Fabricius, 1804, subgenus Dendrolasius Ruzsky, 1912 (Hymenoptera: Formicidae) from east Palaearctic. Annales Zoologici (Warsaw) 55: 83-94.
 * Radchenko, A. 2005. Monographic revision of the ants (Hymenoptera, Formicidae) of North Korea. Annales Zoologici 55(2): 127-221.
 * Ran H., and S. Y. Zhou. 2012. Checklist of chinese ants: formicomorph subfamilies (Hymenoptera: Formicidae) II. Journal of Guangxi Normal University: Natural Science Edition 30(4): 81-91.
 * Tamura H., Y. Nakamura, K. Yamauchi, and T. Fujikawa. 1969. An ecological survey of soil fauna in Hidaka-Mombetsu, Southern Hokkaido. Journal of the Faculty of Science Hokkaido University, Zoology 17(1): 17-57.
 * Terayama M. 1977. Checklist of the known ants of Saitama Prefecture. Insects and nature 12(4): 26-27
 * Terayama M. 2009. A synopsis of the family Formicidae of Taiwan (Insecta: Hymenoptera). Research Bulletin of Kanto Gakuen University. Liberal Arts 17:81-266.
 * Terayama M., Choi, B.M., Kim, C.H. 1992. A check list of ants from Korea, with taxonomic notes. Bulletin of the Toho Gakuen 7:19-54.
 * Terayama M., S. Kubota, and K. Eguchi. 2014. Encyclopedia of Japanese ants. Asakura Shoten: Tokyo, 278 pp.
 * Terayama Mamoru. 2009. A synopsis of the family Formicidae of Taiwan (Insecta, Hymenoptera). The Research Bulletin of Kanto Gakuen University 17: 81-266.
 * Terayama, M. 2009. A synopsis of the family Formicidae of Taiwan (Insecta; Hymenoptera). The Research Bulletin of Kanto Gakuen University 17: 81-266.
 * Teruyama. M. 1988. Ant fauna of Saitama Prefecture, Japan. ARI Reports of the Myrmecologists Society (Japan) 16: 4-13
 * Wilson E. O. 1955. A monographic revision of the ant genus Lasius. Bulletin of the Museum of Comparative Zoology 113: 1-201
 * Yamauchi K. 1968. Additional Notes on the Ecological Distribution of Ants in Sapporo and the Vicinity . Journal of the Faculty of Science Hokaido University, series VI, Zoology 16(3): 382-395.
 * Yamauchi K. 1979. Taxonomical and ecological studies on the ant genus Lasius in Japan (Hymenoptera: Formicidae). I. Taxonomy. Sci. Rep. Fac. Educ. Gifu Univ. (Nat. Sci.) 6: 147-181.