Geoscience Reference
In-Depth Information
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Forest Guards
Several species of ants have developed symbi-
otic relations with Neotropical plants. Aztec
ants have developed a mutualistic relationship
with the cecropia tree, protecting the tree from
other herbivores, and in return consume the
glandular nodules rich in carbohydrates pro-
duced at the base of new growth. Acacia ants
will tenaciously clean the areas around an aca-
cia tree, their home, quickly eliminating any
plants that sprout in the immediate area. Other
ants will defend their host tree from herbivores.
Still others will live within acacia trees but pro-
vide no benefit to the tree and simply exploit
the tree's resources.
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the dry season. Insects can be the most significant
herbivores of dry forest vegetation. The actual di-
versity of insects within the seasonal forests of the
Neotropics is unknown.
Ants play a crucial role in destroying and recy-
cling organic material. Leaf-cutter ants are a sub-
group of the fungus-growing ants present in the
Neotropics (see Chapter 3). Army ants are swarm-
ing ants that are important predators of the rain-
forest. Army ants are social ants with a queen,
soldiers, and worker classes. They form large col-
onies reaching as many as 1 million individuals
and practice group predation in which the pack
swarms the prey, killing and dismembering it to
bring it back to their temporary nest. They are
nomadic and hunt on the ground and in trees.
They are constantly on the move only stopping at
underground nests or in hollow logs during their
reproductive cycles. Large bullet ants are com-
mon in the seasonal forests of the Neotropics. They can be as large as 1 in (25 mm)
long. They live at the base of trees or in tree cavities.
Termites are important factors in decomposing and recycling in seasonal forests
and are an indispensable food resource during the dry season for several mammals,
birds, and reptiles. Termites are social animals living in large groups, in tree cav-
ities, stumps, or on the soil surface (see Figure 5.11). Chapter 3 provides a detailed
look at termites.
Neotropical butterflies and moths are highly diverse. A few families, most genera,
and practically all species living in the Neotropics are endemic to the region. Families
of Neotropical butterflies include the brightly colored swallowtails, the whites, and
the blues. The nymphs are another highly diverse and abundant group of butterflies.
Less is known about moths. Larvae of tropical moths are often plant eaters, but some
are leaf miners, stem borers, flower feeders, or fruit and seed consumers.
The Neotropics host a vast array of other insects. Numerous beetle species are
present. Some are brightly colored, others nondescript. Some common forest bee-
tles include long-horned beetles, dung and carrion beetles, harlequin beetles, fun-
gus beetle, and wood-boring metallic beetles. Cockroaches are another common
decomposer found in the forest. Mosquitoes are common in many of the seasonal
forests during the wet season, but thankfully most disappear in the drier months.
Some may carry diseases such as malaria, yellow fever, and dengue fever among
others. Once the forest is cleared, disease-carrying mosquitoes can be a problem for
the human populations that settle in the area.
Spiders, whip scorpions, scorpions, and centipedes are common in the Neo-
tropical dry forests. Orb spiders build webs of strong silk, ant spiders impersonate
