Download Entomology CheatSheet1 Modified with Diagrams

Insect Morphology, seg. body divided into head, thorax, abdomen. Mouth including mandibles. Three pairs of legs attached to the thorax, One pair of antennae. Exoskeleton. Usually, one or two pairs of wings attached
to the thorax. (Insect Wings): Apterygota – adults like immature without wings; Pterygota – adults have wings (Exopterygota -the wings develop externally on the nymph body; Endopterygote – wings develop inside of
body in immature insects and not visible until adult immerges from pupae) Mouthparts-- Chewing insects- Some have chew. mthpts. as larvae, not adults. Mandible-2 mandibles, one on each side of the head.
Positioned between labrum & maxillae. Typically the largest mouthparts of chewing insects. Used to masticate food items. Open outwards and come together medially. In carnivorous chewing insects, they can be modified
to be more knife-like. In herbivorous chewing insects, they are more typically broad and flat on their opposing faces. In male stag beetles, the mandibles are modified to such an extent that they do not serve any feeding
function, but are instead used to defend mating sites from other males. In ants, the mandibles also serve a defensive function. In bull ants, the mandibles are elongate and toothed, used as hunting appendages. In bees,
the primary use of the mandibles is to manipulate and shape wax. Many wasps have mandibles adapted to scraping and ingesting wood fibers. Maxilla-Situated beneath the mandibles. Paired maxillae manipulate food
during mastication. Can have hairs and "teeth" along their inner margins. At the outer margin, the galea is a cupped or scoop-like structure, which sits over the outer edge of the labium. Have palps, which are used to
sense the characterstics of potential foods. Labium-a quadrupedal structure, although it is formed from two fused secondary maxillae. Can be described as the floor of the mouth. With the maxillae, it assists manipulation
of food during mastication or chewing or, in the unusual case of the dragonfly nymph, extends out to snatch prey back to the head where mandibles can eat it. In the honey bee, the labium is elongated to form a tube and
tongue, and these insects are classified as having chewing and lapping mouthparts Hypopharynx-The hypopharynx is a somewhat globular structure, arising from the base of the labium. It assists swallowing. Siphoning
insects-The typical example is the moths and butterflies, although there are variations. All but a few adult Lepidoptera lack mandibles (the mandibulate moths have fully developed mandibles as adults), with the
remaining mouthparts forming an elongated sucking tube, the proboscis. Proboscis-Held coiled under the head when not in use. During feeding, it is extended to reach the nectar of flowers. The proboscis is a long tube
that is formed by heavily modified maxillae, specifically the galea. Piercing and sucking insects- Proboscis-The defining feature of the order Hemiptera is the possession of mouthparts where the mandibles and
maxillae are modified into a proboscis, sheathed within a modified labium, which is capable of piercing tissues and sucking out the liquids. Stylet-Paired mandibles and maxillae are present, together forming the stylet,
which is used to pierce an animal's skin. During piercing, the labium remains outside the food item's skin, folding away from the stylet. Sponging insects- Labellum-The housefly is the typical sponging insect. The
labium gives the description, being articulate and possessing at its end a sponge-like labellum. Paired mandibles and maxillae are present, but much reduced and non-functional. The labium forms a proboscis which is used
to channel liquid food to the oesophagus. The housefly is able to eat solid food by secreting saliva and dabbing it over the food item. As the saliva dissolves the food, the solution is then drawn up into the mouth as a
liquid.The labellum's surface is covered by minute food channels, formed by the interlocking elongate hypopharynx and epipharynx, which form a tube leading to the oesophagus. The food channel draws liquid and
liquefied food to the esophagus by capillary action Ametabolous – Without Metamorphosis(Young resembles the adult, except smaller)Hemimetabolous Incomplete Metamorphosis(Egg, nymph, adult)
Holometabolous –Complete Metamorphosis(Egg, larva, pupa, adult) Beneficial Insect Traits-Pollination of many flowering plants, Decomposition of organic materials, Recycling of carbon, nitrogen, and other essential
nutrients, Control of populations of harmful invertebrates including other insects, Direct production of foods as honey, Manufacture of products as silk Insect Pests – (10,000 species)Damage Crops, Household Pests,
Parasites, Biting and Stinging Insects, Prey on domestic animals, Eat human food, clothing & possessions, Destroy trees, wood, paper Disease Vectors-Mosquitoes – malaria, arboviral encephalitides, dengue fever, Rift
Valley fever, West Nile encephalitis viral infection; Fleas – plague; Lice – lice infestation. The Integument- the part of an insect that makes up the hard exoskeleton that allows insects their freedom of movement without
loss of defense and protection. It is made up of three parts, the most visible of which is the outer cuticle and its attendant bristles and hairs, below this are the epidermis and the basement membrane. The Cuticle- A
relatively thin layer of non-cellular material which lines the external surface of the body as well as lining the tracheae the anterior and posterior sections of the alimentary canal and parts of the reproductive system.
Flexible, elastic and white when first formed and stays this way in many larval forms. In most adults it undergoes chemical processes which result in hardening and darkening and which are referred to as sclerotization.
The cuticle can be divided into two layers, a very thin outer layer called the epicuticle which contains no chitin and is highly resistant to water and other solvents. Beneath this is the much thicker procuticle which can again
be divided into two distinct layers, an outer exocuticle which lies immediately below the epicuticle and an inner endocuticle which consists of a large number of layers of protein and chitin fibers laid down in a laminated
pattern such that the individual strands in each layer cross each other thus creating an extremely tough and flexible substance. Below the cuticle lie the other two components of the integument, the epidermis which is a
single layer of secretary cells and the basement membrane which is an amorphous layer about 0.5 micrometers thick. The Nervous System- Consists of a brain. A pair of slender connectives cords run, side-by-side from
the brain to the end of the insect's abdomen are known as the 'ventral nerve cord'. These connective cords meet at intervals along the insect's body at the 'ganglia'. In the most primitive design there is one pair of ganglia
per body segment, thus, as the head is made up out of 6 fused body segments, it contains 6 pairs of ganglia, these are collected into 2 groups. Each of 3 ganglia, the foremost of which is called the brain and the hindmost
the subesophageal ganglion. The ganglia function to coordinate the activities of the body segment they represent. In the most basic design there are usually 3 thoracic ganglia and 8 abdominal ganglia but in most of the
higher insects some of abdominal ganglia have been lost, or become fused with those nearer the head. In the cockroach there are 3 thoracic and only 6 abdominal ganglia and in the hornet there are only 2 thoracic
ganglia and 3 abdominal ganglia, the hindmost of which is very much larger than the other two because it is made up of a number of ganglia fused together. This trend culminates in insects such as the common house fly,
where all the abdominal and thoracic ganglia have become fused into a single compound body-ganglion. Breathing- Most insects breathe passively through their spiracles (special openings in the side of their cuticle) and
the air reaches the body by means of a series of smaller and smaller pipes called Tracheae when their diameter is large and Tracheoles when their diameter is very small. Diffusion of gases is effective over small distances
but not over larger ones, this is one of the reasons insects are all relatively small. Insects which do not have spiracles and tracheae, such as some Collembola, breathe directly through their skins, also by diffusion of gases.
The number of spiracles an insect has is variable between species, however they always come in pairs, one on each side of the body, and usually one per segment. Some of the Diplura have eleven pairs, with four pairs on
the thorax, but in most of the ancient forms of insects, such as Dragonflies and Grasshoppers there are two thoracic and eight abdominal spiracles. However in most of the remaining insects there are less; so that
Hoverflies, Syrphidae, have only two pairs, both of which are on the thorax and none on the abdomen while many Mosquito larvae and aquatic Beetle larvae have only one abdominal pair of spiracles. Many insects have
valves that allow them to close their spiracles, thus preventing water loss. The tracheae, which are thin pipes, spread out from the spiracles to reach the whole body, with the smallest tracheoles contacting single muscle
cells individually. In some of the Collembola each spiracle produces a tree branch, or tree root, of tracheae that are separate from those of other spiracles. However in most insects the tracheae are all linked through a
series of longitudinal pipes called trunks and many smaller connections. Dorsal Longitudinal Trunk near the top, or back, of the insect's body; Lateral Longitudinal Trunk running along the sides just in from the spiracles;
Ventral Longitudinal Trunk running along the belly of the insect. In many insects, particularly the larger hymenoptera, the tracheae also link to a series of air sacs which can store air. Most insects can use their body
muscles to squeeze their tracheae and air sacs thus forcing air out, and on release of the muscular tension, drawing fresh air into the large tracheae. In insects like the dragonflies this is a continuous action, but in others
it is irregular, as in cockroaches, or only occurs after active exercise as in the larger hymenoptera. Ears- Many but not all insects can hear sounds, some even hear sounds that we can't hear ourselves. Insects hear
through one of four different ways, the most common of which is the tympanum. Tympanal organs always occur as paired organs, they are composed of a thin cuticular membrane (the tympanum) stretched across an air
space of some sort and some form of connection to the nervous system. In the Orthoptera (Grasshoppers and Crickets) tympanum are common, though situated in different places in different species, i.e. on the first
thoracic segment in Grasshoppers and on the front legs in the Crickets. Tympanal organs also occur in the Cicada (Cicadidae, Hemiptera) and some families of the Lepidoptera, (i.e. Noctuidae, Geometridae, and
Pyralididae). The other three forms of hearing organs are 1) Johnston's Organ, via the movement of hairs on the antennal scape i.e. the Mosquito Aedes aegypti. 2) Auditory Hairs these occur on some Lepidopteran larvae
as well as on some Orthoptera. 3) The Pilifer; this is a unique auditory organ found only in the head of certain species of Hawk Moths of the subfamily Choerocampinae its optimum frequency is between 30 and 70 kHz
which would allow it to hear the echolocation calls of many of the larger insectivorous bats. Touch is an extremely important sense to insects and like smell insects have developed many different ways to detect
mechanical stimulus, these all involve some form of physical change in the receptor, the most common are hairs attached to nerves which react when the hairs are moved, these are called Trichoid sensilla. Another
common type looks more like a drum with something pressing up against the skin of the drum from beneath, these are called Campaniform sensilla. Mechanoreceptors detect not only the physical interaction with another
body but also air movements, changes in air pressure and also changes in the stresses being applied to the insects cuticle, thus allowing it to better control its movements and maintain balance. Insects also use modified
forms of the various sensory detectors described above to detect, changes in temperature, humidity and also in some cases to detect infra red radiation, x-ray radiation and the Earth's magnetic field.Insect ecology is
the scientific study of how insects, individually or as a community, interact with the surrounding environment or ecosystem. Insects play significant roles in the ecology of the world due to their vast diversity of form,
function and life-style; their considerable biomass; and their interaction with plant life, other organisms and the environment. Since they are the major contributor to biodiversity in the majority of habitats, except in the
sea, they accordingly play a variety of extremely important ecological roles in the many functions of an eco-system. Taking the case of nutrient recycling; insects contribute to this vital function by degrading or
consuming leaf litter, wood, carrion and dung and by dispersal of fungi. Insects form an important part of the food chain, especially for entomophagous vertebrates such as many mammals, birds, amphibians and reptiles.
Insects play an important role in maintaining community structure and composition; in the case of animals by transmission of diseases, predation and parasitism, and in the case of plants, through phytophagy and by plant
propagation through pollination and seed dispersal. From an anthropocentric point of view, insects compete with humans; they consume as much as 10% of the food produced by man and infect one in six humans with
a pzthogen. Insect Sociality- In 1971, E. O. Wilson more precisely defined the maximum degree of sociality in insects as eusociality. According to his definition, eusocial insects possess 3 outstanding features; they care
for their young(the young require care), there is an overlap in generations, and there is a reproductive division of labor. Eusociality appears only in Hymenoptera( all ants, honey bees, stingless bees, bumblebees, some
allodapine bees, some seat bees, one wasp species in Sphecidae, all paper wasps) and Isoptera(all termites). Societies generally form colonies in which individuals remain together, care for their offspring, and cooperate to
do certain tasks. Caste System- females have different functional roles (feeding their young, building their nest, foraging for food, defending the colony). Mating within the Colony- A female that is multiply mated by
different males will bear young that are not as close genetically to one another than those that are produced from a female mated with one male. Likewise, degrees of relatedness are coused by the presence of multiple
queens (polygyny) and egg-laying workers(gamergates). Some workers are known to be involved with thelytokous (female producing) and arrhenotokous (male producing) parthenogenesis. There are also cases of
ergatoid (worker-like) individuals that are actually mated with males within the colony and thus are capable of producing offspring much like those of the queen. In Hymenoptera, it is common that dominant workers
produce all or most if the male offspring in their colony. Forensic Entomology- A forensic entomologist can tell whether a body has been moved from city to country, buried in soil or submerged in water then exposed,
moved from one region to another, or between a cool place and a warm place by identifying the species of insect on the body, the stage of the species, and how long the specimen has been in said stage. The blowfly is
often one of the first species to be present on a murdered human’s body. In 2 weeks, maggots can reduce the biomass of a human body by 60%. Fly maggots usually indicate a more recent murder, while beetle larvae
indicate a less recent murder. Robert Hooke- presented his “Micrographica” in 1665. This included prints that were among the first detailed descriptions of insects. He figured and discussed the sting of a bee, the wings
and foot of a housefly, the head and eyes of a drone fly, the egg of a silkworm, a complete bluebottle fly, the larva and pupa of a mosquito, adult male and female gnats, a plume moth, an ant, a body louse, and a silver
fish. Was the first and most famous entomological illustrators. Mosquito Diseases- Dengue fever, Malaria, Pogosta disease (Karelian fever, Ockelbo disease, Sindbis fever), West Nile Tick Diseases- Babesiosis, Tickborne encephalitis, Lyme disease, Rickettsial diseases[along with lice](Rocky Mt. Spotted Fever, Typhus rickettsialpox, Boutonneuse fever, African Tick Bite fever, etc.) Cucloid Midge Diseases- African Horse Sickness,
Bluetounge disease Other Diseases (Vectors)- American tripanosomiasis(assassin bugs of the subfamily Triatominae), Leishmaniasis(Sandfly), Plague(flea), African tripanosomiasis/sleeping sickness(Tsetse fly)
Beneficial insects- any of a number of species of insects that perform valued services like pollination and pest control. The concept of beneficial is subjective and only arises in light of desired outcomes from a human
perspective. In farming and agriculture, where the goal is to raise selected crops, insects that hinder the production process are classified as pests, while insects that assist production are considered beneficial. In
horticulture and gardening; pest control, habitat integration, and 'natural vitality' aesthetics are the desired outcome with beneficial insects. Encouraging beneficial insects, by providing suitable living conditions, is a pest
control strategy, often used in organic farming, organic gardening or Integrated Pest Management. Companies specializing in biological pest control sell many types of beneficial insects. Harmful Insects-Insects
considered pests of some sort occur among all major living orders with the exception of Ephemeroptera (mayflies), Odonata, Plecoptera (stoneflies), Embioptera (webspinners), Trichoptera (caddisflies), Neuroptera (in the
broad sense), and Mecoptera (also, the tiny groups Zoraptera,Grylloblattodea, and Mantophasmatodea). Conversely, of course, essentially all insect orders primarily have members which are beneficial, in some respects,
with the exception of Phthiraptera (lice), Siphonaptera (fleas), and Strepsiptera, the three orders whose members are exclusively parasitic Insects are considered as pests for a variety of reasons including their: direct
damage by feeding on crop plants in the field or by infesting stored products, indirect damage by spreading viral diseases of crop plants (especially by sucking insects such as leafhoppers), spreading disease among
humans and livestock, and annoyance to humans. Insect Classification- Kingdom: Animalia, Phylum: Arthopoda, Subphylum: Mandibulata, Superclass: Hexapoda, Class: Insecta
Protura, Collembola, Diplura, Thysanura, Ephemeroptera, Odonata, Blattodea, Isoptera, Grylloblattodea, Dermaptera, Plecoptera, Orthoptera, Phasmatodea, Psocoptera, Mallophaga, Anoplura, Hemiptera, Cicadidea,
Thysanoptera, Neuroptera, Coleoptera, Strepsiptera, Mecoptera, Siphonaptera, Diptera, Trichoptera, Lepidoptera, Hymenoptera
KEY!!!!
Proturans pg341…Springtails/Snowfleas pg343….Diplurans pg347…Silverfish pg351…Mayflies pg355…Dragon/Damselflies pg363…Roaches pg391…Termites pg399…Ice Insects pg405
Earwigs pg207…Stoneflies pg411…Grasshoppers/Crickets pg415…Walking Sticks pg445…Booklice/barklice pg 451…Chewing Lice pg453…Sucking Lice pg455… True Bugs pg459
Cicadas/Aphids/Hoppers pg489…Thrips pg515…Lacewings/antlions pg525…Beetles pg533…Twisted Wing Parasite pg623…Scorpionflies pg625…Fleas pg629…Flies pg633…
Caddisflies pg693…Butterflies/moths…pg697…Bees/ants/wasps pg801…
Sphinx Moth Caterpillar
Giant Silkworm
Uncovered
Caterpillar Swallowtail Caterpillar Caddisfly Larva
Longhorn Beetle
Larva
Blowfly Larvae
Mosquito Larva and Pupa
Dragonfly Nymph
Antlion Larva
Darkling Beetle Larva