Common Orders of Insects
Bees, ants, wasps, and sawflies (Order
Hymenoptera) have two pairs of membranous wings and chewing mouthparts;
some have tongue-like mouthparts for drinking nectar. All except
sawflies have a distinct “waist” between their second
and third tagmata. Females have a well-developed ovipositor, which
is sometimes developed into a venom-bearing stinger. All ants and
some bees and wasps are social insects, living in long-lived colonies
with a reproductive queen (or queens) and a large number of non-reproductive
workers. Other bees and wasps are solitary. Many wasps are parasitoids,
meaning they lay their eggs on or inside another insect, and their
larvae feed inside and devour the host. Bees feed on nectar and
pollen as adults.
and moths (Lepidoptera) have four wings covered with colored
scales that rub off easily, and mouthparts that form a tube (proboscis)
for drinking nectar or sap. Butterflies hold their wings vertically
at rest, while moths either hold their wings roof-like, curled around
the body, or flat. Also, butterflies have threadlike antennae with
a knob at the end, while moths have various other shapes of antennae
(whiplike, featherlike, or comblike). While the adults sip nectar
to provide energy for flying and mating, the real work of feeding
and growth is done by the larvae (called caterpillars), which are
powerful eating machines. Each species of moth or butterfly is usually
specialized to feed in the larval stage on one or more plant species.
The pupa is called a chrysalis in butterflies, and it is attached
by a silken belt to a plant. Moth pupae are often hidden in a silken
Flies, midges, mosquitoes, and gnats (Diptera)
have one pair of membranous wings, while the second pair is reduced
into knobs called halteres. The mouthparts are designed for lapping,
sucking, or piercing. The larvae (called maggots) are soft, wingless,
and legless, and most live in soil or decaying material. Some flies,
like some wasps, are parasitoids whose larvae feed and develop inside
the bodies of other living insects.
Beetles (Coleoptera) are identified by
their modified forewings (elytra) which form a protective and often
colorful shell. Most beetles have chewing mouthparts with well-developed
mandibles. Beetles may be aquatic or terrestrial, and may be predators,
scavengers, or rarely parasites. Beetle larvae, called grubs, may
be predators or herbivores. Some feed on wood inside live or dead
Bugs, hoppers, cicadas, aphids, and scales
(Hemiptera) have a pair of forewings that fold over the back, covering
their short membranous hindwings. The forewings cross each other
or are held roof-like over the back, distinguishing bugs from beetles,
whose forewings meet in a straight line down the back. Hemipterans
have beaklike mouthparts. Many species suck plant juices, while
others feed on small insects and even small vertebrates. Most are
terrestrial but a few are aquatic with oar-like legs. Many have
glands that extrude strong odors to repel predators and enemies.
The nymphs are wingless and usually resemble miniature adults.
Grasshoppers, crickets, and katydids (Orthoptera)
are heavy-bodied insects with hind legs that often are enlarged
for jumping. Their leathery forewings protect membranous hind wings.
They may be herbivores or predators. They use characteristic sounds,
made by rubbing wings or legs against the body, to attract mates
and establish territories.
Mantids (Mantodea) are long thin hard-bodied
insects with a flexible neck and a triangular head with strong jaws.
They sit perched with their forelegs raised while waiting to catch
prey, hence the name “praying mantis.”
Dragonflies and damselflies (Odonata)
are large slender insects with long membranous wings, large compound
eyes, long legs, and sharp biting mouthparts. Both the adults and
the aquatic nymphs (naiads) hunt and capture insect prey. They typically
are found near water, but adults can range many miles. Dragonflies
perch with wings held horizontal and perpendicular to the body,
while damselflies hold their wings more parallel to the body.
Mayflies (Ephemeroptera) have large triangular wings and long
slender tails. Adults live only a few days, emerging in swarms to
perform aerial mating dances above lakes, rivers, or streams. They
live for one to several years as aquatic nymphs (naiads), with gills
and two tail-like filaments, feeding on small aquatic plants and
sticks (Phasmatodea) are long slender plant-feeding insects.
They have chewing mouthparts and feed on a variety of plants, including
toyons and oaks in California. A primitive walking stick, Timema,
occurs in the inner coastal range of California. Timema
adults and nymphs are wingless and green to brown. Adults only reach
about one inch in length.
Other terrestrial insect orders known or likely
to occur at Quail Ridge include cockroaches (Blattaria), earwigs
(Dermaptera), termites (Isoptera), thrips (Thysanoptera), snakeflies
(Rhaphidioptera), silverfish and bristletails (Thysanura), fleas
(Siphonaptera), booklice and barklice (Psocoptera), net-veined insects
(Neuroptera), scorpionflies (Mecoptera), and webspinners (Embioptera).
Aquatic insects that may occur in the Berryessa Reservoir, and perhaps
in the Reserve’s stock ponds, are alderflies and dobsonflies
(Megaloptera), stoneflies (Plecoptera), and caddis flies (Trichoptera).
Photo Credits: Title, Giant Water
Bug and Butterfly (Mike Benard), Stink Beetle (Joyce Gross), Damselfly
(Nick Kurzenko), Walking Stick (Robert Potts). For more pictures