Identification and Habits
of Key Ant Pests in the
Pacific Northwest
Ants (Hymenoptera: Formicidae) are an easily
recognized group of social insects. The workers
are wingless, have elbowed antennae, and have a
petiole (narrow constriction) of one or two segments
between the mesosoma (middle section) and the
gaster (last section) (Fig. 1).
Ants are one of the most common and abundant
insects. A 1990 count revealed 8,800 species of ants
had been described and that number has increased
to more than 14,000. There are still a number of
undescribed ant species in the world. The true
number is probably more than 30,000.
Ants are also one of the most widely distributed
of all insect groups. They occur from the Arctic
tree line to the humid tropics, from Alaska to the
extreme tip of South America, to the tip of Africa,
Australia, and even to all the islands in the oceans.
They are the most abundant of all social insects.
Since there are so many species of ants, and in such
diverse habitats, it becomes obvious that ants are
one of humans’ principal insect competitors. Ants
infest buildings as a nuisance, feed on human foods,
and even cause structural damage.
Ants are also annoying because of their biting or
stinging habits. Ant stings are responsible for a
number of human fatalities in the United States
each year. The effects of stings on a human depend
on the ant species and the sensitivity of the person.
Most deaths are caused by a hypersensitive reaction
leading to anaphylactic shock.