Entomology

Aedeagus

the copulatory organ of an insect, analogous to the penis in mammals

Air sacs

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

Ametabolous

Synonymous with 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 muscles that move the antenna are located at its base.

Apterygota

Primitively wingless insects. No metamorphosis

Arachnida

The class containing the spiders, ticks, and mites, among many other diverse forms. Arachnids have two major body regions, eight legs, and no antennae. Most are predators or parasites of other animals

Arthropods

Animals, in the phylum Arthropoda, with bilateral symmetry, chitinous exoskeletons, segmented bodies, jointed appendages.

Asexual reproduction

Reproduction that doesn't necessarily require mating.

Basement membrane

Non-living layer that protects the epidermis from the hemolymph

Binomial system of nomenclature

Our two name system for naming species of living things - The Genus and the species within it. The monarch butterfly's binomial scientific name is Danaus plexippus. Always italicized, with first name capitalized and second name not.

Bisexual reproduction

Reproduction requiring mating between a male and female parent.

Cerci

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

Chilopoda

The class containing 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 poly-saccharid ("many- sugared") compound that forms the structural framework for the arthropod exoskeleton. Composed of repeating, linked molecules of glucosamine.

Chorion

The 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 chitinous 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; 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.

Family

The divisions within orders of living things. The monarch butterfly is in the family Danaidae within the order Lepidoptera.

Fat body

A storage organ in the insect's body. Well nourished insects are full of fat body. Also converts nitrogenous waste 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.

Genus (plural genera)

The divisions of life within families. The monarch butterfly is in the genus Danaus within the family Danaidae. The Genus name is always capitalized and always italicized.

Gills

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

Halteres

Highly modified wings used for balance rather than flight. Usually are club shaped structures; found on the metathorax of true flies (Diptera).

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 miniature 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

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 muscle.

Hindgut

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. See Poikilothermic.

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 (JH)

A chemical produced indirectly by the insect's brain that tells the epidermis what kind of cuticle to make when it next molts. High JH and high MH result in another immature cuticle; MH without JH results in an adult cuticle. In insects that go through complete metamorphosis, high MH with a little JH results in a pupal cuticle.

Kingdom

The largest division of life on earth. Insects are in the Kingdom Animalia.

Labium

The "bottom lip" of an insect. Often have sensory, leg-like palps which 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 and usually the hardest structures 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 filiment

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 (egg)

Molting fluid

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

Molting hormone (MH)

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

Middle part of digestive system. Where digestion and absorption of nutrients occurs. Only part of gut not lined with cuticle. Ends at 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 (plural ocelli)

"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.

Order

Divisions of life within classes. Lepidoptera is the order within the class Insecta containing the moths and butterflies.

Ovary

The primary sex organ of females, responsible for making haploid eggs. In insects, the ovaries are composed of a number of ovarioles, each of which functioning 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 on the 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.

Phylum

The great divisions of life within kingdoms. Insects are in the Phylum Arthropoda.

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.

Proboscis

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 in to 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

The "hairs" found on insects. Chitonous outgrowths of the exoskeleton.

Species

A population of organisms capable of producing viable offspring and reproductively isolated from similar populations. The scientific name of a species always consists of two Latinized words; the first is genus to which it belongs and the second is the name of the species within the genus. The genus is always capitalized; the species name is not.

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.