Wasps make up an enormously diverse array of insects, with some
30,000 identified species. We are most familiar with those that
are wrapped in bright warning colorsones that buzz angrily
about in groups and threaten us with painful stings.
But most wasps are actually solitary, non-stinging varieties.
And all do far more good for humans by controlling pest insect populations
Differences From Bees
Wasps are distinguishable from bees by their pointed
lower abdomens and the narrow "waist," called a petiole,
that separates the abdomen from the thorax.
They come in every color imaginable, from the familiar yellow
to brown, metallic blue, and bright red. Generally, the brighter
colored species are in the Vespidae, or stinging wasp, family.
All wasps build nests. Whereas bees secrete a waxy substance
to construct their nests, wasps create their familiar papery abodes
from wood fibers scraped with their hard mandibles and chewed into
Social vs. Solitary Wasps
common paper wasp (Polistes exclamans) photographed at Dallas
Zoo in Texas
Wasps are divided into two primary subgroups: social and solitary.
Social wasps account for only about a thousand species and include
formidable colony-builders, like yellow jackets and hornets.
Social wasp colonies are started from scratch each spring by
a queen who was fertilized the previous year and survived the winter
by hibernating in a warm place. When she emerges, she builds a small
nest and rears a starter brood of worker females. These workers
then take over expanding the nest, building multiple six-sided cells
into which the queen continually lays eggs. By late summer, a colony
can have more than 5,000 individuals, all of whom, including the
founding queen, die off at winter. Only newly fertilized queens
survive the cold to restart the process in spring.
Solitary wasps, by far the largest subgroup, do not form colonies.
This group includes some of the wasp family's largest members, like
cicada killers and the striking blue-and-orange tarantula hawks,
which can both reach 1.5 inches in length. Whereas social wasps
use their stingers only for defense, stinging solitary wasps rely
on their venom to hunt.
Most animals have developed a well-earned fear of
stinging wasps and give them a wide berth. Creatures who haplessly
stumble upon a wasp colony or have the audacity to disturb a nest
will find themselves quickly swarmed. A social wasp in distress
emits a pheromone that sends nearby colony members into a defensive,
stinging frenzy. Unlike bees, wasps can sting repeatedly. Only females
have stingers, which are actually modified egg-laying organs.
Impact on the Ecosystem
Despite the fear they sometimes evoke, wasps are extremely
beneficial to humans. Nearly every pest insect on Earth is preyed
upon by a wasp species, either for food or as a host for its parasitic
larvae. Wasps are so adept at controlling pest populations that
the agriculture industry now regularly deploys them to protect crops.