|
''Polyergus'', also called Amazon ants,〔 is a small genus of 14 described species of "slave-raiding" ants. Its workers are incapable of caring for brood, in part due to their dagger-like, piercing mandibles, but more importantly, because in the evolution of their parasitism on certain species of the host genus "Formica", they have lost the "behavioral wiring" to carry out even rudimentary brood care, or even to feed themselves. ''Polyergus'' workers exist in essence as a specialized brood-acquiring caste in their mixed ''Polyergus/Formica'' colonies, maintaining the ''Formica'' worker force by robbing brood, especially pupae, of particular species in the closely related genus ''Formica'' in massive colony-to-colony raids. The captured ants are generally referred to as "slaves" in scientific and popular literature, though recent attempts have been made to apply other human cultural models, such as describing the ''Polyergus'' individuals of a colony as "raiders" or "pirates" or "kidnappers" and the ''Formica'' workers as "helper-ants", or "domesticated animals". Biologists describe the system as parasitism by "dulosis" (slavemaking) by ''Polyergus'' on the host ''Formica'' species. ''Polyergus'' obtains its ''Formica'' work force by stealing pupae from nearby ''Formica'' colonies and carrying them back to its own nest. Back in the ''Polyergus'' nest, ''Formica'' workers are eventually helped to emerge from the cocoons and pupal exuvia by ''Formica'' workers already living there. The new workers quickly assimilate the characteristic odor of the mixed-species population of the ''Polyergus'' colony—without violence or coercion. The ''Formica'' workers that emerge in the mixed-species colony go on to nurse the brood, forage, maintain the nest, feed their adult captors and their mother the queen, and perform other colony upkeep duties. As far as is known, all established ''Polyergus'' colonies have only one queen. However, many contain ergatoids, large, worker-like forms with large gasters. These may be substitutes reproductive individuals after the queen's death, but this has not been proven. To found a new colony, a lone ''Polyergus'' queen invades a nest of the host species, or encounters and moves in with a colony-founding queen of the host species and her first few workers. In the latter case, the host queen is allowed to survive until her little colony has reared a sufficient number of host workers to support the parasite queen, something the ''Polyergus'' queen cannot do herself. A young ''Polyergus'' queen kills the existing ''Formica'' queen (immediately if sufficient workers are present, later if these are not yet reared) and becomes accepted by the ''Formica'' workers. These proceed to rear the first and all subsequent ''Polyergus'' brood. Clearly, this complicated and lengthy process often fails, as ''Polyergus'' colonies are relatively rare, even though each mature colony produces dozens or hundreds of new potential queens each year. To counteract the natural mortality of the ''Formica'' worker population, ''Polyergus'' workers must conduct regular raids over a 6-8 week period, every summer over the 10-15-year life span of their colony.〔Trager, James C. ("Global revision of the genus Polyergus" ), ''Zootaxa''. Retrieved 24 October 2013.〕 ==Species== ;''lucidus'' group * ''Polyergus lucidus'' Mayr, 1870 – eastern United States, southern Ontario * ''Polyergus longicornis'' Smith, 1947 – southeastern United States * ''Polyergus montivagus'' Wheeler, 1915 – New England states to northern Florida in eastern United States, southern Ontario, Canada & west to Wisconsin and northern New Mexico, United States * ''Polyergus oligergus'' Trager, 2013 – Florida, United States * ''Polyergus ruber'' Trager, 2013 – southeastern United States * ''Polyergus sanwaldi'' Trager, 2013 – United States, New England west to North Dakota ;''rufescens'' group * ''Polyergus rufescens'' (Latreille, 1798) – all of Europe, to western China and Kazakhstan * ''Polyergus breviceps'' Emery, 1893 – north-central United States, west to Colorado, northern Arizona * ''Polyergus bicolor'' Wasmann, 1901 – Wisconsin and Michigan, United States, west to North Dakota and south-central Canada * ''Polyergus mexicanus'' Forel, 1899 – Dakotas and Arkansas, to western USA and Canada, and south at high altitude in mountains of Durango, Mexico. * ''Polyergus topoffi'' Trager, 2013 – High desert to mid-elevation mountains from Hidalgo, Mexico to southern Arizona, United States * ''Polyergus vinosus'' Trager, 2013 – southern California to northern Baja California, Mexico ;''samurai'' group * ''Polyergus nigerrimus'' Marikovsky, 1963 – Mongolia, Tuvan Republic, southern Russia * ''Polyergus samurai'' Yano, 1911 – Japan, Korea, eastern China, southeastern Russia ;''incertae sedis'' * ''Polyergus texanus'' – excluded from ''Polyergus'' by Trager (2013) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Polyergus」の詳細全文を読む スポンサード リンク
|