''Acropyga exsanguis'' is a species of

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,0 ...

in the subfamily

Formicinae The Formicinae are a subfamily within the Formicidae containing ants of moderate evolutionary development. Formicines retain some primitive features, such as the presence of cocoons around pupae, the presence of ocelli in workers, and littl ...

. It lives in underground nests in Mexico, Central and South America.LaPolla, J.S. 2004a. ''Acropyga'' of the world. Contributions of the American Entomological Institute. 33(3) p.47

Description

Over 450 ant species have been collected at

La Selva Biological Station La Selva Biological Station is a protected area encompassing 1,536 ha of low-land tropical rain forest in northeastern Costa Rica. It is owned and operated by the Organization for Tropical Studies,Matlock, R., & Hartshorn, G. (1999). La selva bio ...

in Costa Rica, including several species of ''

Acropyga ''Acropyga'' is a genus of small formicine ants. Some species can be indirect pests. '' A. acutiventris'', which is found from India to Australia, tends subterranean, root-feeding mealybugs of the species '' Xenococcus annandalei''. Living, grav ...

''. These are small, stocky ants less than long, and ''A. exsanguis'' is not easy to distinguish from related species. The dorsal surface is rather more densely covered in short hairs than is the case with ''

Acropyga keira ''Acropyga'' is a genus of small formicine ants. Some species can be indirect pests. '' A. acutiventris'', which is found from India to Australia, tends subterranean, root-feeding mealybugs of the species '' Xenococcus annandalei''. Living, gra ...

'', another species found at La Selva.

Distribution and habitat

This neotropical ant is known from Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, Venezuela and Argentina. It occurs at altitudes up to about , typical habitats including wet or moist lowland rainforest, mesophyll forest and montane wet forest. It lives in colonies underground and this subterranean existence means it is poorly represented in ant surveys; it has been found most often by sifting through leaf litter, but has occasionally been observed under stones or visiting bait. The fact that it is much more common than might be expected from survey results is shown by the vast swarms of males that were seen twice in 1991 at La Selva Biological Station during the wet season.

Ecology

This ant lives underground in a large, diffuse nest. The ants move the nest upwards and downwards according to the conditions of the soil, descending deeper when the ground becomes dry. The nests have multiple queens, either because they were founded by several newly-mated reproductives, or because they have recruited further queens since their foundation. This ant lives in symbiosis with several species of

mealybug Mealybugs are insects in the family Pseudococcidae, unarmored scale insects found in moist, warm habitats. Many species are considered pests as they feed on plant juices of greenhouse plants, house plants and subtropical trees and also act as a ...

which live in its nest; the mealybugs suck sap from roots, and the ants feed on the honeydew that the mealybugs secrete. Species of mealybug found in the nest include ''

Geococcus coffeae ''Geococcus coffeae'' is a species in the mealybug family, Pseudococcidae, commonly known as the coffee root mealybug, or brown scale. It lives underground where it inserts its mouthparts into roots and sucks the sap. Description The adult femal ...

'', ''

Rhizoecus coffeae ''Rhizoecus'' is a genus of true bugs belonging to the family Pseudococcidae. The genus has almost cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of ...

'', '' Pseudorhizoecus proximus'', ''

Rhizoecus caladii ''Rhizoecus'' is a genus of true bugs belonging to the family Pseudococcidae. The genus has almost cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of ...

'', and ''

Rhizoecus falcifer ''Rhizoecus'' is a genus of true bugs belonging to the family Pseudococcidae. The genus has almost cosmopolitan distribution. Species: * ''Rhizoecus advenoides'' Takagi & Kawai, 1971 * ''Rhizoecus albidus ''Rhizoecus'' is a genus of true b ...

'', and on several occasions, queen ants have been observed setting off on their nuptial flight carrying a fertilised female mealybug.

References

{{Taxonbar, from=Q3645957 Formicinae Insects described in 1909 Hymenoptera of North America Hymenoptera of South America Taxa named by William Morton Wheeler