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What You Might Find

Arthropods

Arthropods belong to the phylum Arthropoda and represent the largest group in the animal kingdom. Insects, spiders, millipedes, centipedes, and crustaceans are all arthropods; together, the arthropods are the most successful group of organisms on the planet! Arthropods share many common features, including a protective external skeleton made of chitin, a segmented body, and paired and jointed appendages. Insects are often the most noticeable and commonly encountered terrestrial group. They can be divided into more than 30 different orders (subgroups). The members of each have certain basic characteristics and behaviors that can be particularly useful for identification. The following include some of the most charismatic, distinctive, and commonly encountered orders covered in this book.

Coleoptera (Beetles)

This is the largest and most diverse group of animals on the planet. Beetles represent about 40 percent of all known insects with over 350,000 described species. Adults tend to be rather large, robust, and conspicuous organisms with a hard exoskeleton and two pairs of wings. The first pair is modified into protective covers, called elytra, which cover the larger, membranous wings beneath. Beetles occur in both terrestrial and aquatic freshwater environments. They have chewing mouthparts; some feed as predators on a variety of other invertebrates, others are herbivores and consume various plant parts, and still others are scavengers on animal dung, carrion, or decaying plant material. Beetles undergo complete metamorphosis. Many beetles are also attracted to artificial lights at night.

Lepidoptera (Butterflies and Moths)

Butterflies and moths are some of the most well-known and charismatic of all insects. Adults tend to be rather large and showy organisms with two pairs of transparent wings that are covered with numerous tiny scales. They have two large compound eyes, two elongated antennae, and siphoning mouthparts (although in some species they are significantly reduced and nonfunctioning), which enable them to drink flower nectar or other fluids. Butterflies are active by day, whereas most moths are nocturnal, although some species are seen during the day. Butterflies and moths undergo complete metamorphosis. Their larvae, known as caterpillars, are primarily plant feeders and have chewing mouthparts.

Hymenoptera (Bees, Wasps, and Ants)

This is a large and diverse group of insects known for their complex social systems that even include division of labor. Adults typically have two pairs of transparent wings, although some groups or individuals may be wingless. Most have chewing mouthparts with the exception of bees, which have a tongue for feeding on flower nectar or other fluids. The majority of adults also have a noticeable constriction between the abdomen and thorax that resembles a narrow waist. Many adults feed on nectar and are common flower visitors. Ants are typically predators, omnivores, or scavengers. All bees, wasps, and ants undergo complete metamorphosis. Their larvae feed on a variety of resources, including prey or pollen provisioned by the adults and plant material. Some are parasites of other insects.

Diptera (Flies)

Flies are a large and cosmopolitan group of insects that get their name for their most obvious behavior—flying. The rear wings are modified and reduced to small, club-shaped structures called halters, which help stabilize the insect during flight. Adults have well-developed compound eyes, short antennae, and diverse mouthparts designed for piercing, sucking, or sponging up liquid foods. Flies undergo complete metamorphosis. The larvae lack legs and live in terrestrial, freshwater, or moist environments where they feed on decaying plant or animal material or are predators or parasites of other animals.

Hemiptera (True Bugs)

This is a large and highly diverse group of insects, especially in size and appearance. Adults have two pairs of transparent wings or forewings that are partially thickened at the base. They have piercing or sucking mouthparts, with most species feeding on plant juices, although some are predatory. True bugs undergo incomplete metamorphosis with immature specimens (called nymphs) closely resembling adults. They are predominantly terrestrial, although a few groups occur in freshwater habitats.

Orthoptera (Grasshoppers, Crickets, Katydids, and Others)

This is a group of larger, robust insects found entirely on land. Adults have two pairs of wings; the first pair is narrow, hardened and leathery and covers a larger, membranous pair below. Both pairs of wings are held over the back while at rest. The hind legs are enlarged and modified for jumping. These insects undergo incomplete metamorphosis with the immature ones (called nymphs) closely resembling adults. Both have chewing mouthparts and feed primarily on plant material.

Odonata (Dragonflies and Damselflies)

This is a small but diverse group of insects. Adults have two pairs of large, transparent wings with extensive veinlike features on them; large compound eyes; and long, slender abdomens. Many adults are brightly colored and showy. They are active, mobile predators with chewing mouthparts. Dragonflies and damselflies undergo incomplete metamorphosis. The immature ones, known as naiads, occur in freshwater systems where they feed on other aquatic organisms.

Blattodea (Cockroaches and Termites)

This is a small and primarily ancient group of insects. Cockroaches are characterized by oval and somewhat flattened bodies, very long antennae, and two pairs of membranous wings. They have chewing mouthparts and are generally considered omnivores.

Neuroptera (Lacewings and Antlions)

This is a group of delicate-looking insects with two pairs of heavily veined, transparent wings. Adults have chewing mouthparts and feed on other insects. The larvae are active predators and have modified jaws to capture prey and suck out the internal fluids. They undergo complete metamorphosis. The adults are weak fliers and are often attracted to artificial lights.

Mantodea (Mantises)

Mantises are large and very charismatic insects. They have an elongated body with a distinctive triangular head, large compound eyes, chewing mouthparts, two pairs of wings, and enlarged front legs that are modified with spines and enable them to capture prey. Both juveniles and adults are highly camouflaged, sit-and-wait predators. They undergo incomplete metamorphosis. Adults are often attracted to artificial lights.

Phasmida (Walking Sticks)

This is a group of large, primarily tropical insects with few species in North America. They have chewing mouthparts and very elongated bodies, legs, and antennae that help them resemble sticks or other vegetation for protection from predators. Most species in our area lack wings. They undergo incomplete metamorphosis.

Dermaptera (Earwigs)

Earwigs are a distinctive and somewhat primitive-looking group of insects. They have elongated, flattened bodies; chewing mouthparts; somewhat elongated antennae; and a distinctive pair of pincer-like features called cerci on the tip of their abdomen. They have two pairs of wings, with the front pair noticeably short and leathery. They undergo incomplete metamorphosis.

Ephemeroptera (Mayflies)

Mayflies are a small group of distinctive and delicate-looking insects. They have elongated bodies, two pairs of transparent wings with the forewings much longer than the hind wings, short antennae, and three elongated filaments off the abdomen. The adults are extremely short-lived and thus have no functional mouthparts. Immature specimens are aquatic. They undergo incomplete metamorphosis. Adults are regularly attracted to artificial lights.

Megaloptera (Alderflies, Dobsonflies, and Fishflies)

This is a group of medium- to large-size, primitive-looking insects. They have elongated, soft bodies with chewing mouthparts, elongated antennae, and two pairs of elongated wings. Despite their large wings, they are poor and quite clumsy fliers. They undergo incomplete metamorphosis. Immature specimens are aquatic. Adults are often attracted to artificial lights at night.

Trichoptera (Caddisflies)

Resembling small moths, caddisflies are primarily nocturnal, weak-flying insects. They have two pairs of transparent wings that are covered in dense hairs. They have elongated bodies; long, thin antennae; and reduced or vestigial mouthparts. The larvae are aquatic and may be predators, herbivores, or scavengers. They undergo complete development. Adults are often attracted to artificial lights at night.

Plecoptera (Stoneflies)

Stoneflies are a primitive group of drably colored, soft-bodied insects. Adults have elongated and somewhat flattened bodies, long legs and antennae, two pairs of membranous wings, and two prominent cerci off the tip of the abdomen. They tend to be short-lived and weak fliers. The nymphs are fully aquatic, requiring clean freshwater habitats. They undergo incomplete metamorphosis. Adults are often attracted to artificial lights at night.