''Acropyga epedana'' is an

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

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 permanently underground in the

Chiricahua Mountains The Chiricahua Mountains massif is a large mountain range in southeastern Arizona which is part of the Basin and Range province of the west and southwestern United States and northwest Mexico; the range is part of the Coronado National Forest. T ...

in Arizona and forms a mutualistic association with the

mealybug Mealybugs are insects in the family Pseudococcidae, unarmored scale insects found in moist, warm habitats. Of the more than 2,000 described species, many are considered pests as they feed on plant juices of greenhouse plants, house plants and ...

'' Rhizoecus colombiensis''.

Description

''Acropyga epedana'' is a tiny pale golden-brown ant with a few erect hairs but many dense appressed hairs. The reproductives have normal compound eyes but the workers have tiny eyes and avoid exposure to light. These ants are very similar in appearance to '' Acropyga goeldii'' and '' Acropyga palaga'' and may be a northern population of ''A. goeldi''. However, there are differences in the extensions to the penis valves that make it likely that the three are in fact separate species. The head of ''Acropyga epedana'' is smaller than that of the other two species. The total length of a worker is .

Distribution

''Acropyga epedana'' is found in the

in Arizona at elevations of between and its range probably extends southwards into the Sierra Madre Occidental Mountains in Mexico. Because there is no sign of the nest above ground, this ant may be under recorded. It is generally found in woodland of

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' ( ) of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere as far south ...

and

oak An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...

Biology

Colonies of ''Acropyga epedana'' are completely subterranean. Nests have been found under boulders and consist of galleries and chambers that may extend to or more underground, and perhaps deeper in the dry season. This species has an obligate trophobiotic relationship with the mealybug, ''Rhizoecus colombiensis''. This underground sap-sucking insect feeds on the roots of plants and the ants herd them and feed on the honeydew they produce. The ants are believed to obtain all their nourishment from this source, and in a laboratory experiment, when they were deprived of their mealybugs, they refused all other forms of food that they were offered. The mealybugs are found clustered on roots in deeper parts of the nest in the passages excavated by the ants. Many of the ants are infested with parasitic

mite Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as eac ...

s. Flights of winged reproductive ants (

alate Alate (Latin ''ālātus'', from ''āla'' (“wing”)) is an adjective and noun used in entomology and botany to refer to something that has wings or winglike structures. In entomology In entomology, "alate" usually refers to the winged form of ...

s) have been seen in mid-summer, shortly after the beginning of seasonal rains. There are often ten times as many male as female alates. Each female emerges from her natal nest carrying a mealybug between her

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

s, presumably to act as a parent of the mealybug herd in the nest she will found. The flying ants hover in a swarm and copulate in mid-air. The females return to the ground after their

nuptial flight Nuptial flight is an important phase in the reproduction of most ant, termite, and some bee species. It is also observed in some fly species, such as '' Rhamphomyia longicauda''. During the flight, virgin queens mate with males and then land ...

s, each still carrying a mealybug, shed their wings, and search for a suitable site to make a new nest. Some may join colonies in existing nests, as evidenced by the fact that there are often several queens in a nest.

References

External links

* {{Taxonbar, from=Q3652217 Formicinae Insects described in 1862 Taxa named by Julius Roger