2 Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA

ZooKeys (2013). Special Issue. 295: 1–277. doi: 10.3897/zookeys.295.4905

РЕФЕРАТ

ОБЗОР БИОЛОГИИ И ЭКОЛОГИИ

Ниже даётся обзорная информация по естествеенной биологии и экологии отдельных видов рода. Here I present a summary of what is known about the natural history of MAC Stenamma species. Биология Неарктических и Палеарктических видов даётся по данным Smith (1957) и DuBois (1998), соответственно.

Неотропические представители рода Stenamma обнаруживаются, главным образом, in mesic лесных условиях на высотах от уровня моря до 3000 м высоты, with the highest record reported at 3700 m at Pico Orizaba in Mexico (Stenamma manni Wheeler). Stenamma specieshave been collected mostly in lowland rainforest, montane wet forest, cloud forest, and dwarf forest. A few species (Stenamma huachucanum, Stenamma lagunum, Stenamma manni) also have been found in seasonal woodland habitats in drier areas of Mexico and the southwestern United States. Stenamma has never been collected in tropical dry forest or scrub environments. One hypothesis for the nearly complete geographic separation of the HOC and MAC is the presence of extensive xeric environments in northern Mexico and the southwestern United States (Branstetter 2012).

Исключительной характеристикой рода Stenamma является то, что многие его виды отличаются хорошей адаптацией к холодному влажному климату. Although present in the lowlands, the diversity and abundance of Stenamma species peak at mid-elevations between 800–1600 m (Branstetter unpublished data). Also, it has been found that Stenamma can be the most common ant genus in leaf-litter samples collected from very wet and cool, cloud forest localities. These ecological traits are in contrast to the pattern seen in ants generally, in which diversity and abundance decrease with elevation. Biogeographic results indicate that Stenamma originated in the Nearctic, potentially preadapting it to thrive in cool montane forest environments (Branstetter 2012).

Большинстов ивдов рода Stenamma species have very cryptic habits. Nests are usually small, and workers are slow moving, often becoming immobile upon disturbance. Consequently, Stenamma is rarely found by the casual observer and most collections are made by sifting leaf-litter from the forest floor. This fact has given Stenamma its stereotype as a "leaf-litter ant genus.” Although nests of many species do occur in the leaf litter, and foragers are common there, recent collecting efforts have revealed that MAC Stenamma species nest in a variety of microhabitats. I have found nests in large logs, in small rotting branches, in and under bark, in steep clay or mud banks, in and under epiphytes, under rocks, in the ground, and under leaves in leaf litter. At least a few Stenamma species nest arboreally. For example, several variants of Stenamma schmidti Menozzi have been found reliably underneath epiphyte clumps in the canopy and by canopy fogging, and Stenamma longinoi sp. n. is known only from one collection under epiphytes in a treefall. Based on circumstantial evidence, I surmise that a few other species have arboreal nests or at least forage arboreally. Stenamma stictosomum sp. n. and Stenamma felixi Mann have been found in epiphytic orchids inspected at quarantine in the U.S., and Stenamma callipygium sp. n. has been collected most often by beating vegetation.

Одним из наиболее интригующих открытий последнего времени стало наблюдение того, что некоторые виды рода Stenamma гнездятся в clay banks. Longino (2005) documented in detail the complex nesting behaviors of Stenamma alas Longino and Stenamma expolitum Smith. Both of these species nest in clay banks in wet forest habitats often along streams, and they exhibit a unique set of behaviors that are thought to be used in evading predation by other ants (possibly army ants specifically). These species construct multiple nests, but only occupy one with brood and a queen; they build each nest with a vertical (Stenamma expolitum) or horizontal (Stenamma alas) turret sunk into a shallow alcove; and they maintain a small clay "door-pebble, ” which is used to block the nest entrance upon encounter with the appropriate disturbance. Reported here for the first time, several other Stenamma species are now known to nest in clay banks. I have found Stenamma diversum Mann, Stenamma megamanni sp. n., Stenamma muralla sp. n., and Stenamma pelophilum sp. n. all nesting in clay banks along streams or on steep clay slopes. Stenamma diversum is particularly interesting, because it has convergently evolved the same nest architecture as Stenamma alas (Branstetter pers. obs.). It nests exclusively in steep clay substrate, and builds a nest entrance with an ear-like turret sunk into the clay. It does not, however, appear to build multiple nests per colony or maintain a door-pebble. Based on where I have collected workers and how the workers are sculptured, I believe other Stenamma species nest in clay banks as well (e.g. Stenamma llama sp. n., Stenamma lobinodus sp. n.). Why does Stenamma nest in clay banks? I hypothesize that like cloud forests, the clay bank habitat is less hospitable to the average ant, and thus provides Stenamma species with a more protected and less competitive environment in which to nest and forage.

Муравейники Stenamma как правило немногочисленный по составу их обитателй и просто устроенные, but there is considerable variation in size and structure. Stenamma diversum, for example, has very small colonies. Nests consist of a single chamber and have at most a dozen workers, a few alates, brood, and a single dealate queen. In contrast, colonies of Stenamma manni and Stenamma megamanni are very large. I have found mature colonies of both species in logs and in the ground (usually underneath a log or rock). They tend to have many chambers containing several hundred to perhaps a thousand workers, along with brood and alates (a thorough census has not been performed). Stenamma alas and Stenamma expolitum have colonies of intermediate size, with up to 200 workers, 50 alates, brood, and a single dealate queen (Longino 2005). Data from nest collections suggest so far that all Stenamma species are monogynous, and that most produce winged queens and males. Остаётся неизвестным, как часто появляются крылатые половые особи и как они расселяются.

СИНОПСИС ВИДОВ 

Список включает 40 видов, из которых 33 новые для науки. 

Stenamma alas Longino 2005. Costa Rica to Ecuador.

Stenamma andersoni Branstetter sp. n. Southern Mexico.

Stenamma atribellum Branstetter sp. n. Honduras.

Stenamma brujita Branstetter sp. n. Mexico to Honduras.

Stenamma callipygium Branstetter sp. n. Guatemala.

Stenamma catracho Branstetter sp. n. Honduras.

Stenamma connectum Branstetter sp. n. Southern Mexico.

Stenamma crypticum Branstetter sp. n. Southern Mexico to Nicaragua.

Stenamma cusuco Branstetter sp. n. Honduras.

Stenamma diversum Mann 1922. Southern Mexico to Nicaragua.

Stenamma excisum Branstetter sp. n. Mexico to Honduras.

Stenamma expolitico Branstetter sp. n. Costa Rica.

Stenamma expolitum Smith 1962. Nicaragua to Costa Rica.

Stenamma felixi Mann 1922. Mexico to Ecuador.

Stenamma hojarasca Branstetter sp. n. Southern Mexico to Honduras.

Stenamma huachucanum Smith 1957. Southwestern U.S.A. to southern Mexico.

Stenamma ignotum Branstetter sp. n. Southern Mexico to Guatemala.

Stenamma lagunum Branstetter sp. n. Northern Mexico.

Stenamma leptospinum Branstetter sp. n. Southern Mexico.

Stenamma llama Branstetter sp. n. Southern Mexico to Guatemala.

Stenamma lobinodus Branstetter sp. n. Mexico.

Stenamma longinoi Branstetter sp. n. Southern Mexico.

Stenamma manni Wheeler 1914. Mexico to Nicaragua.

Stenamma maximon Branstetter sp. n. Southern Mexico to Honduras.

Stenamma megamanni Branstetter sp. n. Southern Mexico to Nicaragua.

Stenamma monstrosum Branstetter sp. n. Honduras to Nicaragua.

Stenamma muralla Branstetter sp. n. Honduras to Nicaragua.

Stenamma nanozoi sp. n. Honduras.

Stenamma nonotch Branstetter sp. n. Southern Mexico to Guatemala.

Stenamma ochrocnemis Branstetter sp. n. Southern Mexico to Honduras.

Stenamma pelophilum Branstetter sp. n. Mexico to Honduras.

Stenamma picopicucha Branstetter sp. n. Honduras to Nicaragua.

Stenamma saenzae Branstetter sp. n. Southern Mexico to Honduras.

Stenamma sandinista sp. n. Nicaragua.

Stenamma schmidti Menozzi 1931a. Nicaragua to Ecuador.

Stenamma stictosomum Branstetter sp. n. Mexico to Honduras.

Stenamma tiburon Branstetter sp. n. Northern Mexico.

Stenamma tico Branstetter sp. n. Nicaragua to Panama.

Stenamma vexator Branstetter sp. n. Mexico.

Stenamma zelum Branstetter sp. n. Honduras to Panama.