Stigmatomma silvestrii

Identification
Total length of workers 3.5 - 4.5 mm. Body color yellowish brown to reddish brown.

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

Biology
S. silvestrii feeds mainly on centipedes. Masuko (1993) discovered and reported the habit whereby queens wound larvae non-lethally and imbibe their haemolymph as food.

Masuko (1986) provides the following account:

Description of larval hemolymph feeding (LHF)

As established by my laboratory observations, LHF of S. silvestrii is a behavior in which adult ants pierce the dorsal integument of the upper abdomen of older larvae by pinching with their sharpened mandibular tips, and then feed upon hemolymph leaking from the puncture (Fig. 1). The larvae are most often pinched at the two intersegmental grooves between the 2nd and the 4th abdominal segments (Fig. 2). In general, queens (inseminated females) perform LHF; except when the colony is starved, it is seldom seen in workers and dealate, uninseminated females. The latter castes instead feed directly on prey, the cuticle of which has been opened either by larvae or adults. Uninseminated females, which are often encountered in field-collected mature nests, are ordinarily observed to labor in a workerlike manner. Queens start each bout of LHF by active antennal stroking and handling of a larva, and then pinch it from either side. Invariably, after several pinchings, the mandibular tip applied to the larval dorsum punctures its integument, and a droplet of hemolymph flows from the wound. The queen at once attaches her lower mouthparts to the puncture to lick the droplet. She then "freezes" motionless for several minutes, during which time the lapping movement of her lower mouthparts, still attached to the puncture, usually ceases, indicating that she is imbibing hemolymph from the larval body cavity using her pharyngeal pump. Each bout of LHF usually involves a single larva. Following LHF the queen ordinarily discharges one or two pure white infrabuccal pellets onto the nest floor, probably the filtered dregs of hemolymph. Queens at this time are often groomed at the mouthparts by workers, which remove the pellet and usually discard it outside the brood chamber.

LHF by queens of developed colonies

LHF is not only performed solely by queens, but it is a queen's only way of obtaining nutrients. Table 1 A shows the feeding time budget of three queens observed in laboratory colonies that were monogynous and mature, i.e., including more than 20 workers (the field data suggest that S. silvestrii colonies become mature, that is, start production of sexuals, when their worker population exceeds about 10). All three queens indulged in LHF to the exclusion of other modes of feeding, even though captured prey items (centipedes or mealworms) were available in the brood chamber throughout the observation period. To confirm this again and to ascertain the time intervals between bouts of LHF, two further queens of monogynous mature colonies were observed with a VTR. One, who was observed continuously for 5 days at 27±1°C under constant light (LL), repeated LHF at intervals of 5.3±0.7 h (mean±SE). The other queen was observed under both LL and DD (constant dark), each for 3 days, at 22±1°C; these periods were preceded by 3-day light and dark adaptation periods, respectively (an infrared light was used for observation in darkness). The difference between mean intervals of LHF by this queen under LL and DD was not statistically significant (ANOVA, F(1,11)=0.508), so the data were combined to yield an interval of 9.1±1.8 h (mean±SE). Also in this VTR study, it was noted that the queens obtained their nutrients exclusively by LHF despite continuous accessibility to prey. It is thus confirmed that nearby prey remains are ignored by S. silvestrii queens, while they repeat LHF at intervals of several hours.

Scarred larvae

Larvae subjected to LHF were always mature or near-mature individuals of the 5th instar, which is the final instar for both female and male larvae in this ant (the larval instars of S. silvestrii are easily determined based on the body size and the chaetotaxy). Usually several members of the 5th instar population are pinched repeatedly, which causes their scars to become increasingly evident (Fig. 2). These observations are confirmed by field collected material (Fig. 3): 149 5th-instar larvae belonging to eight winter nests were collected at Manazuru during December 1982 and April 1983. Their body size, which was measured when alive as the width of the 4th abdominal segment with an ocular micrometer accurate to 0.025mm, ranged from 0.475-0.800 mm, with a mean of 0.647 mm. Those with scars thought to have been made during the preceding active season, and characteristic of LHF, were all in the size class above 0.625 mm. Figure 3 shows that among 106 larvae of this class, only 44 (41.5%) had scars: seven (15.9%) had only "faint" scars, 19 (43.2%) had "faint" to "intermediate" scars, and 18 (40.9%) had at least one "bold" scar (for classification of scar degrees see Fig. 2).

The punctures close shortly after LHF by hemolymph coagulation and scarred larvae do not die from their wounds nor are they cannibalized, as would generally be the case with damaged larvae of higher ants. In well-fed laboratory colonies most scarred larvae were observed to continue feeding and to succeed in pupation. However, if these colonies are starved, larvae most exploited for LHF and hence the most debilitated were devoured and consumed before the same-sized but unscarred or weakly scarred larvae.

Among 169 larvae contained in cocoons collected in the field during 1981 and 1984, 125 (74.0%) had scars characteristic of LHF. These facts suggest that, even under natural conditions, the potentially destructive effect of LHF on the larval population is not profound. It is still probable, however, that LHF has some unfavorable effects on its recipients, e.g., causes delay in their development or lowers their rates of survival, especially in colonies with few larvae.

LHF by foundresses

The possibility of LHF by foundresses (colony founding queens) is of interest. Since the appearance of the first workers is crucial to subsequent colony survival, it is expected that foundresses will show a low rate of LHF compared to queens in developed colonies, in order to rear the first workers as quickly as possible. Unlike the foundresses of higher ants, which maintain their first brood on nutrients regurgitated while claustral, Amblyopone foundresses forage alone outside the nest (Wheeler 1933; Haskins and Haskins 1951; Haskins 1970).

Table 1 B shows the feeding time budget of three haplometrotic (singly colony-founding) queens, each of which was collected with her immatures and later observed in the laboratory. Foundress 82-299 showed both LHF and prey feeding, but she spent much more time at the latter. Only prey feeding was observed in the case of foundress 84-40. Prey availability was experimentally lowered during observation of foundress 81-96. In her case only prey feeding and cannibalism of the pupae were recorded during the studied 10-h period. Outside this period, however, she was observed to perform LHF on some particular larvae, which were later cannibalized. Thus, as predicted, their feeding characteristics differed greatly from those of queens in mature colonies, when prey was available.

Nomenclature

 *  silvestrii. Stigmatomma silvestrii Wheeler, W.M. 1928d: 97 (w.) JAPAN. Ogata, 1987: 103 (m.); Terayama, 1989b: 345 (q.); Masuko, 1990b: 221 (l.). Combination in Amblyopone: Brown, 1960a: 169 (see also p. 197); in Stigmatomma: Yoshimura & Fisher, 2012: 19. See also: Masuko, 1993: 35.

References based on Global Ant Biodiversity Informatics

 * Abe A. 2006. Effect of thinning the artificial forests on the species composition of ants living in forest floor. Yahagigawa-kenkyu. 10:105108
 * Azuma, S. and M. Kinjo. 1987. Family Formicidae, In Checklist of the insects of Okinawa. The Biological Society of Okinawa, Nishihara. Pages 310-312.
 * CSIRO Collection
 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Choi B.-M. 1987. Taxonomic study on ants (Formicidae) in Korea (1). On the genus Monomorium. Journal of the Institute of Science Education (Cheongju National Teachers' College) 11:17-30.
 * 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. 1997. Distribution of Ants (Formicidae) in Korea (18). Ants Fauna in island Paekryongdo and Taechongdo. Journal of Chongju National University of Education 34: 119-138.
 * Choi B.M., K. Ogata, and M. Terayama. 1993. Comparative studies of ant faunas of Korea and Japan. 1. Faunal comparison  among islands of Southern Korean and northern Kyushu, Japan. Bull. Biogeogr. Soc. Japan 48(1): 37-49.
 * Choi B.M., Kim, C.H., Bang, J.R. 1993. Studies on the distribution of ants (Formicidae) in Korea (13). A checklist of ants from each province (Do), with taxonomic notes. Cheongju Sabom Taehakkyo Nonmunjip (Journal of Cheongju National University of Education) 30: 331-380.
 * 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.
 * Fukumoto S., Jaitrong W. and Yamane S.K. 2013. Ant Fauna of Kuro-shima, Iwo-jima and Take-shima islands, Kagoshima Prefecture, southwestern Japan. Nature of Kagoshima 39: 119-125
 * Fukumoto S., W. Jaitrong, and S. Yamane. 2013. Ant fauna of Take-shima, Iwo-jima and Kuro-shima islands, Kagoshima Prefecture, southwestern Japan. Nature of Kagoshima 39: 99-105.
 * Guénard B., and R. R. Dunn. 2012. A checklist of the ants of China. Zootaxa 3558: 1-77.
 * Harada Y. 2000. Ant fauna of the forest floor of the Koshikijima Islands, Kagoshima-ken, southern Japan. Ari 24: 4-11.
 * Harada Y. S. Koto, N. Kawaguchi, K. Sato, T. Setoguchi, R. Muranaga, H. Yamashita, A. Yo, and S. Yamane. 2012. Ants of Jusso, Isa City, Kagoshima Prefecture, southwestern Japan. Bull. biogeogr. Soc. Japan 67: 143-152.
 * Harada Y., H. Yadori, M. Yoneda, R. Takinami, K. Nagahama, Y. Matsumoto, A. Oyama, S. Maeda, and S. Yamane. 2009. Ant fauna of Tanegashima (Hymenoptera, Formicidae). Nankiseibutu, the Nanki Biological Society 51(1): 15-21.
 * Harada Y., K. Nishikubo, K. Matsumoto, M. Matsuda, Y. Inazawa, Y. Ozono, S. Koto, N. Kawaguchi, and S. Yamane. 2011. Ant fauna of Japanese beech (Fagus crenata) forests in southwestern Japan. Bull. Biogeogr. Soc. Japan 66: 115-127.
 * Harada Y., K. Tashiro, K. Ebihara, H. Yadori, M. Yoneda, R. Takinami, K. Nagahama, and K. Hayashi. 2008. Ant fauna of the lavas of Sakurajima Volcano, Southern Japan. Bull. Biogeogr. Soc. Japan 63: 205-215.
 * Harada Y., M. Enomoto, N. Nishimata, and K. Nishimuta. 2014. Ants of the Tokara Islands, northern Ryukyus, Japan. Nature of Kagoshima 40: 111121.
 * Harada Y., T. Sameshima, K. Tashiro, and K. Ebihara. 2006. Ant fauna of the Imuta Lake area, Kagoshima Prefecture, southern Japan. Nanki organisms 48(1): 43-49.
 * Harada Y., Y. Matsumoto, S. Maeda, A. Oyama, and S. Yamane. 2009. Comparison of ant fauna among different habitats of Yaku-shima Island, southern Japan. Bull. Biogeogr. Soc. Japan 64: 125-134.
 * Hisamatsu M. 2004. List of Hymenoptera Recorded in Ibaraki Prefecture. Bulletin of Ibaraki Nature Museum 7: 125-164.
 * Hosoichi S., M. Yoshimura, Y. Kuboki, and K. Ogata. 2007. Ants from Yakushima Island, Kagoshima Prefecture. Ari 30: 47-54.
 * Hosoichi S., W. Tasen, S. H. Park. A. Le Ngoc, Y. Kuboki, and K. Ogata. 2015. Annual fire resilience of ground-dwelling ant communities in Hiraodai Karst Plateau grassland in Japan. Entomological Science 18: 254–261.
 * Hosoishi S. 2006. Ant fauna of Noko Island. pp99-107. In: The floristic and faunistic surveys of the Noko Island.
 * Hosoishi S., M. Yoshimura, Y. Kuboki, and K. Ogata. 2007. Ants from Yakushima Island, Kagoshima Prefecture. Ari 30: 47-54.
 * Hu C.-H. 2006. Indigenized conservation and biodiversity maintenance on Orchid Island. PhD Thesis, graduate school of the University of Minnesota. 150 pages.
 * Ichikawa A. 1999. Records of ants observed from several localities of Osaka Prefecture, Japan, -1. Ari 23: 1-3.
 * Kawahara Y., S. Hosoyamada, and S. Yamane. 1999. Ant fauna of the Terayama Station for Education and Research on Nature, Kagoshima University. Bulletin of the Faculty of Education, Kagoshima University. Natural Science 50: 147-156.
 * Kim B., Ryu D., Park S., and J. Kim. 1994. Systematic study on ants from coasts of Korean Peninsula (Hym: Formicidae). Korean journal of entomology 24: 293-309.
 * Kim B.J. 1996. Synonymic list and distribution of Formicidae (Hymenoptera) in Korea. Entomological Research Bulletin Supplement 169-196.
 * Kim B.J.; Kim, J.H.; Kim K 1998. Systematic study of Ponerinae (Hymenoptera: Formicidae) from Korea. Korean Journal of Entomology 28:145-154.
 * Kim G., and D. Lyu. 2012. Distribution of ants (Insecta, Hymenoptera) in Chiaksan Mountain, Prov Gangweon, Korea. Journal of Korean Nature 5(2): 127-129.
 * Kim K.I., C.H. Kim, and B. Choi. 1989. The ant fauna of the southern shore in Gyeongsangnamdo, Korea. Journal of Gyeongsang Nat. Univ. 28(2): 213-226.
 * Kim et al. 1993. Systematic study of ants from Chejudo Province. Koran Journal of Entomology 23(3): 117-141.
 * Kondoh M. 1961. Ants from Hakone region. Hakone Hakubutsu 1:16-27.
 * Li Z.h. 2006. List of Chinese Insects. Volume 4. Sun Yat-sen University Press
 * Lyu D. 2008. Taxonomic study on the Poneromorph subfamilies group (Hymenoptera: Formicidae) in Korea. Korean J. Appl. Entomol. 47(4): 315-331.
 * Masuko, K. 2010. Nest density and distribution of subterranean ants in an evergreen broadleaf forest in Japan with special reference to Amblyopone silvestrii. Entomological Science 13:193
 * Matsumura S. and Yamane Sk. 2012. Species composition and dominant species of ants in Jigenji Park, Kagoshima City, Japan. Nature of Kagoshima 38: 99107
 * Matsumura S., and S. Yamane. 2012. Species composition and dominant species of ants in Jigenji Park, Kagoshima City, Japan. Nature of Kagoshima 38: 99-107.
 * Menozzi C. 1940. Contribution à la faune myrmécologique du Japon. Mushi. 13: 11-12.
 * Minato M., T. Kameyama, F. Ito, and T. Itino. 1996. A preliminary report of ant fauna in Gagawa Prefecture. Ari 20: 9-13.
 * Ogata. K., Touyama, Y. and Choi, B. M. 1994. Ant fauna of Hiroshima Prefecture, Japan. ARI Reports of the Myrmecologists Society (Japan) 18: 18-25
 * Ohkawara K., and Y. Fukushima. 1998. A Preliminary report of ant fauna in Ishikawa Prefecture, Central Japan. Ari 22: 6-9.
 * Onoyama K. 1976. A premilinary study on the ant fauna of Okinawa-ken, with taxonomic notes (Japan; Hymenoptera: Formicidae). Ecol. Stud. Nat. Cons. Ryukyu Isl. II: 121-141.
 * Onoyama K. 1989. Three ants (Hymenoptera: Formicidae) new to Hokkaido, Japan. Japanese Journal of Entomology 57:604.
 * Our results Winkler 2009
 * Park S. H., S. Hosoishi, K. Ogata, and E. Kasuya. 2014. Changes of Species Diversity of Ants Over Time: a Case Study in Two Urban Parks. J. Fac. Agr., Kyushu Univ., 59 (1), 7176.
 * Park S. H., S. Hosoishi, K. Ogata, and Y. Kuboki. 2014. Clustering of ant communities and indicator species analysis using self-organizing maps. Comptes Rendus Biologies http://dx.doi.org/10.1016/j.crvi.2014.07.003
 * Park S.J., and B.J. Kim. 2002. Faunal comparison of ants among Cheongsando and other islands of South Sea in Korea. Korean Journal of Entomology 32(1): 7-12.
 * 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.
 * Sakai H. 2002. Reproductive flight season of Japanese ants. Ari 26: 33-39.
 * Sato T., N. Tsurusaki, K. Hamaguchi, and K. Kinomura. 2010. Ant fauna of Tottori prefecture, Honshu, Japan. Bulletin of the Tottori Prefectural Museum 47: 27-44.
 * Shimono A., and S. Yamane. 2003. Ant species diversity on Okinoerabu-jima, the Ryukyus, southern Japan. For the Establishment of Remote Islands Study (Kagoshima Univ.) 3: 11-29.
 * Skarbek C. J., M. Noack, H. Bruelheide, W. Hardtle, G. von Oheimb, T. Scholten, S. Seitz, M. Staab. 2019. A tale of scale: plot but not neighbourhood tree diversity increases leaf litter ant diversity. Journal of Animal Ecology DOI: 10.1111/1365-2656.13115
 * Sonobe R. 1977. Ant fauna of Miyagi prefecture, Japan. Japanese Journal of Ecology 27: 111-116.
 * Sugihara Y. 1933. Hymenoptera-Fauna in Province Tosa. Formicidae. [In Japanese and English.]. Kansai Konchu Zasshi 1:79-86.
 * Tang J., Li S., Huang E., Zhang B. and Chen Y. 1995. Hymenoptera: Formicidae (1). Economic Insect Fauna of China 47: 1-133.
 * Terayama M. 1989. The ant tribe Amblyoponini (Hymenoptera, Formicidae) of Taiwan with description of a new species. Japanese Journal of Entomology 57:343-346.
 * Terayama M. 1992. Structure of ant communities in East Asia. A. Regional differences and species richness. Bulletin of the Bio-geographical Society of Japan 47: 1-31.
 * 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., K. Ogata, and B.M. Choi. 1994. Distribution records of ants in 47 prefectures of Japan. Ari (report of the Myrmecologists Society of Japan) 18: 5-17.
 * Terayama M., S. Kubota, and K. Eguchi. 2014. Encyclopedia of Japanese ants. Asakura Shoten: Tokyo, 278 pp.
 * Terayama M., and K. Murata. 1987. Relation between ant communities and vegetations of Toshima island, the Izu Islands. Bull. Biogeogr. Soc. Japan 42(9): 57-63.
 * Terayama M., and K. Murata. 1990. Effects of area and fragmentation of forests for nature conservation: Analysis by ant communities. Bull. Biogeogr. Soc. Japan 45(2): 11-17.
 * Terayama M., and S. Kubota. 2002. Ants of Tokyo, Japan. ARI 26: 1-32.
 * Terayama M., and S. Yamane. 1984. Ants of Yaku-shima Island, the northern Ryukyus, with reference to their altitudinal distribution (Insecta: Hymenoptera). Cons. Rep. Yaku-shima Wildness Area, Kyushu, Japan, pp. 643-667. Nat. Cons. Bureau, Env. Agency, Japan.
 * Terayama, M. 2009. A synopsis of the family Formicidae of Taiwan (Insecta; Hymenoptera). The Research Bulletin of Kanto Gakuen University 17: 81-266.
 * Terayama. M. and Inoue. N. 1988. Ants collected by the members of the Soil Zoological Expedition to Taiwan. ARI Reports of the Myrmecologists Society (Japan) 18: 25-28
 * Teruyama. M. 1988. Ant fauna of Saitama Prefecture, Japan. ARI Reports of the Myrmecologists Society (Japan) 16: 4-13
 * Touyama Y. 2000. Estimating species richness: an application of the time unit sampling method to a myrmecofaunal survey. Jpn. J. Enviro. Entomol. Zool. 11: 51-60.
 * Wheeler W. M. 1928. Ants collected by Professor F. Silvestri in Japan and Korea. Bollettino del Laboratorio di Zoologia Generale e Agraria della Reale Scuola Superiore d'Agricoltura. Portici 22: 96-125.
 * Xu Z.-H., and J. J. Chu. 2012. Four New Species of the Amblyoponine Ant Genus Amblyopone (Hymenoptera: Formicidae) from Southwestern China with a Key to the Known Asian Species. Sociobiology 59(4): 1175-1196.
 * Yamane S. 2016. How many species of Ants in Amami Islands? (in Japanese). Part 2, chapter 1 in How many species of Ants in Amami Islands? Pp. 92-132.
 * Yamane S., S. Ikudome, and M. Terayama. 1999. Identification guide to the Aculeata of the Nansei Islands, Japan. Sapporo: Hokkaido University Press, xii + 831 pp. pp, 138-317.
 * Yamane S., Y. Harada, and K. Eguchi. 2013. Classification and ecology of ants. Natural history of ants in Southern Kyushu. 200 pages
 * Yamane S.; Ikudome, S.; Terayama, M. 1999. Identification guide to the Aculeata of the Nansei Islands, Japan. Sapporo: Hokkaido University Press, xii + 831 pp. pp138-317.
 * Yamane, S.; Iwai, T.; Watanabe, H.; Yamanouchi, Y. 1994. Ant fauna of the Tokara Islands, northern Ryukyus, Japan (Hymenoptera, Formicidae). WWF (Worldwide Fund for Nature) Japan Science Report 2(2):311-327.