ENT 201: Exam #1

Accessory Gland

Paired glands are found in the reproductive tracts of both male and female insects, although their functions differ in the two sexes. In males, they produce substances to support the sperm and nuptial gifts; females use the glues and other substances to secure their eggs. In stinging insects, the accessory glands make venom.

Aedeagus

bug dick

Air Sacs

Unreinforced areas in trachea that allow the insect to force air in and out of the respiratory system

Ametabolous

Meaning no metamorphosis. Found in most primitive, wingless insects. Young basically look like miniature adults; adults distinguished by having functional sex organs

Ammonia

A toxic waste product produced when animals metabolize protein. Aquatic insects can get rid of it easily by producing large amounts of dilute, ammonia-laden urine. Terrestrial insects convert it to uric acid to save water.

Antenna

The primary chemical reception (“smell”) sensors of an insect. Insects have one pair; the main part of the antenna, and the part furthest from the body, is the “flagellum.” All the muscels that move the antenna are located at its base

Apterygota

Primitively wingless insects. No metamorphosis

Arachnida

Have two major body regions, eight legs, and no antennae. Most are predators or parasites of other animals

Arthropods

bilateral symmetry, chitonous exoskeletons, segmented bodies, jointed appendages

Basement membrane

Non-living layer that protects the epidermis from the hemolymph.

Cerci

Paired appendages near the end of insect’s abdomens that usually have a sensory function (much like antennae on the butt!) but are often modified for other functions.

Chilopoda

The class contains the centipedes, arthropods with many-segmented bodies, one pair of legs per segment, one pair of antennae, flattened bodies, and venomous fangs. All are predators.

Chitin

The polysaccharide (“many-sugared”) compound forms the structural framework for the arthropod exoskeleton. Composed of repeating, linked molecules of glucosamine

Chorion

Shell of an insect egg made of protein

Class

The divisions of life within phyla. Insecta is a class within Arthropoda

Compound eye

A visual sensory organ composed of many smaller sub-units called ommatidia or “facets.” Forms a mosaic image with resolution dependent on the number of ommatidia

Crustacean

An arthropod with a calcium-reinforced chitonous exoskeleton, two major body regions, two pairs of antennae, and, usually, five pairs of legs. Most are marine (living in the ocean) or aquatic; the class includes many other diverse forms. Now thought to be ancestral to insects

Cursorial

adapted for running

Cuticle

The non-living parts of the insect exokeleton. Composed of three layers: endocuticle, exocuticle, and epicuticle

Diapause

A resting state that insects enter to avoid inhospitable environmental conditions

Diploid

The normal number of chromosomes in most cells. Diploid cells have a pair of each chromosome; one member of each pair came from the animal’s mother, the other from its father

Diplopoda

The class containing the millipedes, arthropods with many-segmented, cylindrical bodies, two pairs of legs per segment, one pair of antennae, and calcium in their exoskeletons. Most are plant feeders or scavengers, and many have potent chemical defenses

Dorsal vessel

The pump in the insect’s circulatory system. Consists of the “heart,” a perforated, muscular tube in the abdomen, and the “aorta” basically a hose that conducts hemolymph forward to the head.

Ejaculatory duct

The tube which conducts sperm from the male reproductive tract into the female- passes through the aedeagus

Elytra

The hard, shell-like for wings of beetles

Endocuticle

The inner-most layer of the cuticle. Composed of chitin and protein; flexible but not stretchy; found throughout exosketeton

Endopterygota

Insects whose wings develop out of sight- those insects that undergo complete metamorphosis

Epicuticle

The outermost and thinnest layer of the cuticle. Composed of waxes, cements, protein; responsible for water-proofing the exoskeleton. Found on all external portions of exoskeleton

Exocuticle

The middle layer of the cuticle; is composed of chitin, protein, and phenolic compounds which give it hardness and rigidity. Found in the exoskeleton wherever strength, hardness, and rigidity are required

Exopterygota

Insects that develop wings on the outside- those that undergo incomplete metamorphosis

Exoskeleton

The external support structure of arthropods. In insects, mostly chitin and other stuff. Composed of the living, single-cell thick epidermis, and the three-layered cuticle. Also lines the foregut, hindgut, and major trachea of the respiratory system.

Fat body

A storage organ in the insect’s body. Well nourished insects are full of fat body. Also converts nitrogenous weaste to uric acid and plays a roll in hormonal control.

Fore-gut

The front part of the insect digestive system. Begins with the mouth and ends at the cardiac valve. Lined with cuticle. Contains crop, which stores excess food for later digestion

Fossorial

Adapted to digging in soil.

Gills

In insects, outgrowths of the tracheal repiratory system that increase the area for gas exchange in some aquatic insects.

Halteres

Highly modified wings used for balance rather than flight. Usually are clubshaped structures; found on the metathorax of true flies

Haplo-diploidy

The sex determination system in Hymenoptera and some other animals, in which a fertilized egg produces a female offspring, while an unfertilized egg produces a male offspring.

Haploid

half the normal number of chromosomes for a given species. Generally only eggs and sperm are haploid; they only contain one of each chromosome.

Hemelytra

The half-leathery, half-membranous wings of true bugs like stink bugs.

Hemimetabolous

synonymous with incomplete or partial metamorphosis. Nymphs look like minature adults, but with developing wing pads rather than functional wings. Nymphs and adults typically have same kinds of mouthparts, feed on the same things, and live in the same places, so they compete with each other

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Hemocytes

Blood cells, primarily responsible for defense against disease and parasites.

Hemolymph

The blood of insects. Contains water, defensive cells, nutrients, hormones, etc., but does not transport oxygen in most insects.

Hemocoel

The body cavity of the insect, generally full of hemolymph bathing all the internal organs and muscles.

Hindgut

The back end of insect digestive tract. Lined with cuticle; packages waste for elimination and reabsorbs water and salts from waste before disposal. Starts at the pyloric valve and ends at the anus

Holometabolous

synonymous with complete metamorphosis. Four life stages- egg, larva, pupa, adult. Larvae and adults often bear no resemblance whatsoever to each other. Larvae and adults may have radically different mouthparts and live and feed in very different places

Homeothermic

Able to maintain a constant body temperature under variable environmental temperatures

Hypopaharynx

A structure in the insect’s mouth that functions much like a tongue. Like other mouthparts, evolved from ancestral legs

Insecta

Arthropods with three major body regions, six legs, one pair of antennae, and, in most species, winged adults. The only flying invertebrates and the dominant life form on the planet in terms of diversity

Instar

A stage in the life cycle of an insect. When an insect molts, it goes from one instar to the next; the adult is the final “perfect” instar, since it has functional sex organs and wings

Juvenile hormone

A chemical produced indirectly by the insect’s brain that tells the epidermis what kind of cuticle to make when it next molts.

Labium

The “bottom lip” of an insect. Often have sensory, leg-like palps that work much like the palps on the maxillae

Labrum

The “upper lip” of the insect’s mouth

Larva

The immature stage of insects that go through complete metamorphosis. Never have anything that looks like wings, no compound eyes, and often very different from adults

Linneaus

The father of the modern classification of life. He formalized the hierarchal system of classification (“King Phillip Cried Oh For Goodness Sakes!”) and the binomial system of nomenclature

Malphigian tubules

The “kidneys” of the insect, responsible for collecting and concentrating metabolic waste in the insect. Join the digestive tract at the beginning of the hindgut

Mandibles

The “jaws” of the insect. Found behind the labrum usually the hardest structure in the body of an insect with chewing mouthparts

Maxilla

leg-like appendages in the mouth of insects that help them manipulate their food and often have taste receptors. Generally behind the mandibles.

Median filament

An extension of the top plate on one of the last abdominal segments that looks like a long tail. Generally found only on some primitive insects and probably sensory

Meiosis

The reduction division of cells in the reproductive organs that produces haploid sperm or eggs

Micropyle

The tiny hole in the chorion of an insect egg allowing sperm to enter and fertilize the ova

Molting fluid

The substance secreted by the epidermis that recycles the old endocuticle when the insect is preparing to molt

Molting hormone

A chemical produced indirectly by the insect brain that signals the insect epidermis to begin making a new exoskeleton and recycle parts of the old

Membranous

Filmy and transparent. Membranous insect wings often look like they are made of cellophane wrapping

Midgut

The middle part of digestive system. Where digestion and absorption of nutrients occur. Only part of gut not lined with cuticle. Ends at the Pyloric valve.

Natatorial

Adapted to swimming

Nymph

The immature stage of an insect that goes through incomplete metamorphosis. Often quite similar to adults, with similar mouthparts; often have compound eyes and visible wing pads that get larger with each successive molt

Nuptial gift

Product or object provided to female (usually) by a male (usually) to persuade her (usually) to mate

Ocellus

“Simple eyes” that don’t form complex images but can detect color, light, and dark. Most insects probably use them to help keep track of time and season.

Oncychphora

A phylum of creatures that may be ancestral to insects. They have many un-jointed legs. Peripatatus is a living example of an Onychphoran

Ootheca

A protective structure many female insects construct around their eggs. A product of the female’s accessory glands. A mantid’s has the texture of Styrofoam; a roach’s looks like a tiny purse

Ovary

The primary sex organ of females, is responsible for making haploid eggs. In insects, the ovaries are composed of a number of ovarioles, each of which functions like a small egg assembly line

Oviducts

The tubes which conduct eggs away from the ovaries.

Oviparous

Lays eggs which hatch some time later

Ovipositor

An appendage found o nthe abdomens of female insects which they use to lay eggs. In some Hymenoptera (bees, ants, and wasps), the ovipositor is modified into a defensive stinger

Ovoviviparous

Produces eggs but holds them internally until they are ready to hatch

Paedeogenesis

Parthenogenic reproduction by an immature form; happens in some insect larvae

Parthenogenesis

Reproduction without mating. Usually results in clones of the mother.

Plastron

In insects, an air bubble trapped by hydrophobic (water-repelling) setae in some aquatic insects which enhances gas exchange

Poikilothermic

Having a body temperature roughly that of the surrounding environment. See homeothermic.

Polyembryony

The condition where a single egg splits into many embryos, producing that many clones of the original egg

Probocis

A feeding structure evolved from the chewing mouthparts of ancestral insects found in some modern insects that feed on liquid diets like nectar

Pronotum

The top plate on the prothoracic segment. Often highly modified for defense, mating contests, or camouflage purposes

Pterygota

Winged insects

Pupa

The stage in complete metamorphosis between the larva and the adult. Generally not mobile, doesn’t eat, doesn’t excrete. In this stage, everything that was the larvae transforms into the adult

Raptorial

Adapted for catching prey animals

Resilin

A rubbery protein that stores energy and provides some stretch in parts of the insect exoskeleton. Also stores energy in some insect muscles

Salivary glands

Glands located near mouth that provide lubrication for swallowed food; sometimes modified to produce venom, anticoagulants, and, in caterpillars, silk

Saltitorial

Adapted to jumping

Seta

he “hairs” found on insects. Chitinous outgrowths of the exoskeleton.

Sperm

male germ cells. Haploid, and produced by the testes.

Spermatheca

A structure in the reproductive tract of female insects which stores sperm until they are needed to fertilize eggs

Spiracles

The holes along the sides of the abdomen and some thoracic segments that open to the tracheal respiratory system

Styli

Peg-like appendages found along the sides of the abdomen in some very primitive insects like silverfish

Testes

Primary male sex organs, make sperm

Thorax

The middle portion of an insect body and the center of locomotion. Always has three segments with, usually, one pair of legs per segment. The segment closest to the head is the prothorax; the middle, the mesothorax, and the hind-most, the metathorax. Wings may be found on the meso- and meta- but never on the prothoracic segment

Trachea

The large respiratory pipes of the insect respiratory system, opening to the outside through the spiracles. Lined with cuticle

Tracheole

The tiny pipes that conduct gases to every living cell in the insect’s body from the larger tracheal elements

Trilobite

Ancient, extinct arthropods which dominated the ocean between 600 and 400 million years ago; distant ancestors of insects

Uric acid

the nitrogenous compound insects form to get rid of nitrogen produced as a waste product of protein metabolism. Relatively non-toxic and solid, it conserves water in the process of getting rid of this metabolic waste

Vas deferens

The tube that conducts sperm away from the testes