Figure 4.17. Leaf-cutter ant (Acromyrmex sp.) cutting lily petal. Photograph by Dan Perlman.left out. Their nests are far smaller than Atta nests,
often in or under a piece of dead wood and often with
a superstructure of loose dead leaf fragments. They
do not excavate soil as extensively as Atta. They may
be subarboreal, nesting in a low branch junction of
an epiphyte-laden tree. Unlike At. cephalotes, Ac.
coronatus is more tolerant of cloud forest conditions.
Colonies occur in clearings and small gaps up to the
ridge crest above Monteverde.
Pest ants. Monomorium pharaonis is a tiny yellow
species that is a pest ant in some Monteverde houses.
This is a classic "tramp" species (Williams 1994),
occurring in buildings throughout the world and eas-
ily transported by humans. It is not native to the New
World and is rarely found outside of buildings. Other
Monteverde pest ants are native species that move
into houses from surrounding habitats. Pheidole
punctatissima is a small brown species, the soldiers
of which have yellow on the back of the head. This
species is common in open disturbed areas and can
achieve remarkably high densities in Monteverde
houses. Camponotus albicoxis is a large brown car-
penter ant with contrasting white on the bases of the
middle and hind legs and is referred to as "cranny ant"
by Monteverde residents (J. Campbell, pers. comm.).
They have ephemeral nest sites that they readily aban-
don. In houses, they may be found in old boxes, be-
hind books on shelves, and beneath unused clothing
in drawers. On discovery by humans or army ants,
workers burst into action, grasping brood and running
in all directions to establish a new nest site in another
dark cavity. They forage nocturnally and are general-
ized scavengers with a preference for sweets. Nests
are also found beneath epiphytes in canopy trees.
Solenopsis geminata is the common tropical fire
ant found in frequently disturbed open areas, such as
where annual crops are planted and around dwell-
ings. They nest in the soil, forming distinct mounds
of excavated soil above their nests. Workers have an
inordinately strong sting for their size. They have the
habit of stealthily climbing up people's legs in large
numbers and then all stinging simultaneously. Fire
ants are generalized scavengers with powerful recruit-
ment abilities. They are usually deemed pests because
of their general nuisance and their ability to damage
small seedlings, but they may also be beneficial as
voracious predators on other pest insects. Solenopsis
geminata is widespread throughout Central America
and southern North America. It is native to Costa Rica,
where it is the only known fire ant species (Trager
1991).Large predators. Some of the more conspicuous ants
in Monteverde are large black ants in the subfamily
Ponerinae. These ants forage solitarily and are preda-
tors on live prey. The three most common large
ponerines in Monteverde are Leptogenys imperatrix,134 Insects and Spiders