Entm Exam 1

Approximate number of known insect species

1 million

Potential Number of insect species

10 million

General habitats in which insects are not found

* deep oceans
* highest mountain peaks
* coldest areas of Arctic and Antarctic

Areas in which insects compete with humans

* crops, cultivated plants
* stored products
* structures, dwellings, furnishings
* disease transmission to humans and animals
* Annoyance

The five common kingdom

Monera= bacteria

Protista= amoeba, paramecium, algae, etc.

Plantae=plants

Fungi= fungi

Animalia=animals

Beneficial aspects of insects

* Pollinators
* food for animals and humans
* indicators of environmental quality
* Art, music, literature
* movies, hobbies, profession

Carolus Linnaeus

“Father of Modern Taxonomy”

Used binomial classification consistently in 10 th ed. of Systemae Naturae in 1758

Binominal classification

Scientific name that consists of genus and species names

Basic units of hierarchical classification

Kingdom

phylum

class

order

family

genus

species

King Philip Came Over For Great Soup

Derivation of phylum name arthropoda

Arthro = joint

Poda = foot

External characteristics of a generalized arthropod

1. Bilateral symmetry
2. body segmented
3. pair of appendages on each body segment
4. some appendages lacking in many groups
5. segmental appendages just posterior to the mouth became mouthparts
6. Body covered by a continuous cuticle secreted by the epidermis

Internal characteristics of a generalized arthropod

1. Dorsal contractile heart in a pericardial sinus
2. a ventral nervous system consisting of two nerve trunks with paired segmental ganglia
3. lining of the foregut and hindgut, respiratory tubes, and parts of glands lined with cuticle

Subphyla of arthropods

Chelicerta and mandibulata

The fiver major classes of arthropods

Arachnida (chelicerata)

Chilopoda (mandibulata)

Diplopoda (Mandibulata)

Insecta (Mandibulata)

Crustacea (Mandibulata)

Characteristics of chelicerata

* ticks, mites, scorpions, daddy-longlegs,
* body divided into cepalothorax and abdomen.
* no antennae
* four pairs of legs

Common names and anatomical characteristics of arachnida

1. lack antennae
2. four pairs of legs
3. mouthparts chelicerate
4. body divided into cephalothorax and abdomen

Major orders of arachnida

* Scorpiones (scorpions)
* araneae ( spiders)
* acari ( ticks, mites)
* opiliones (daddy-longlegs)

Common name of scorpiones

Scorpions

Common name of Acari

tick, mite

Anatomical characteristics of scorpiones

* lack antennae
* mouthparts developed into pedipala (a chelicera adapted as a food getting structure)
* end of abdomen with stinger

anatomical characteristics of arari

* four pairs of legs
* no antennae
* chelicerate unsegmented

Common name of araneae

spider

Anatomical characteristics of aranea

* lack antennae
* constriction between cephalothorax (fused head and thorax) and abdomen
* 4 pairs of legs

common name of Opiliones

daddy-longlegs

Anatomical characteristics of Opiliones

* lack antennae
* body stout
* no constriction between cephalothorax and abdomen
* legs 5 times longer than body

Characteristics of Mandibulata

* one or two pairs of antennae
* mouthparts mandibulate (chewing)
* number of legs vary from 3 to 10 pairs of legs

common name of chilopoda

centipede

anatomical characteristics of chilopoda

* one pair of antennae
* one pair of legs per body segment
* body divided into head and trunk
* 1st pair of legs a poison claw
* predator

Derivation of class name chilopoda

Chilo = lip

poda = foot

referring to the poison claws associated with the head

Common name of diplopoda

Millipede

Anatomical characteristics of diplopoda

* one pair of antennae
* two pairs of legs per body segment
* body divided into head and trunk
* plant feeder

Derivation of class name diplopoda

di= two

poda = foot

common name of crustacea

* crayfish
* sowbugs
* pillbugs
* crabs
* shrimps, etc

anatomical characteristics of crustacea

* two pair of antennae
* mouthparts mandibulate (chewing)
* body divided into cephalothorax and abdomen
* 5 to 7 pairs of legs

Common name of insecta

insects

Derivation of class name insecta

“cut into segments”

anatomical characteristics of insecta

* one pair of antennae
* body divided into 3 parts
* three pairs of legs
* some with one of two pairs of wings

supposed ancestor of advanced phyla

Marine worm stock about 600 million years ago

Supposed habitat of the ancestor of advanced invertebrate phyla

Marine habitat

Geological age of the supposed arthropod ancestor

Cambrian, 600 million years ago

Living representative of stage 1

Annelid (earthworm)

Important developments leading to the arthropod ancestor in stage 1

development of the body cavity (the coleom) and body segmentation

Living representative of stage 2

Phylum: onychophora

Anatomical advancement in stage 2 of arthropod development

appearance of unjointed appendages on each body segment. Improvement in eyes and antennae

Anatomical changes that created a trilobit E

postural segment disappears into the head, postural segments 2-4 became mouthparts. Improvement to eyes and antennae

Fate of the postural segments 1 to 6 in living arthropods

* postural segment 1 = lost in head
* 2 = Mendibles
* 3 = maxillae
* 4 = labium
* 5 = leg
* 6 = leg

Two subphyla that arose from a trilobite-like ancestor

* mandibulata
* chelicerate

Tagmata

* body region
* consists of the head, thorax, and abdomen

Characteristics of apterygota

subclass of Insecta in which adults lack wings and ancestors never had wings

Characteristics of Pterygota

subclass of incesta in which adults have wings ( some may have secondarily lost wings) and ancestors had wings

Location of wings

* one pair on mesothorax
* one pair on metathorax
* Insects with just one pair of wings have wings on mesothorax and metathoracic wings absent

terms for the body wall

integument or exoskeleton

cuticle

consists of epicuticle, exocuticle, and endocuticle and not the epidermis

layers of the exoskeleton

* epicuticle (cement layer, waxy layer, cuticulin layer)
* exocuticle ( melanized and sclerotized)
* endocuticle ( soft, flexible)
* Epidermis (cellular layer)

advantages of the exoskeleton

* protects soft internal organs
* protects against evaporation
* protects against disease organism
* performs structural strength
* supports internal organs
* provides site for sense organs
* functions as a locomotory agent

Disadvantages of the exoskeleton

* limits size of the insect
* limits amount of food that can be stored
* limits movement of appendages
* limits tactile senses
* no means of temperature regulation
* mist be shed to grow or change form

specialized epidermal cells

modified epidermal cells that secrete wax and other substances on the surface of the body wall

types of gland cells

* gland cell
* tormogen cell
* trichogen cell

seta

A hair-like projection arising from the epidermis, performs many sensory functions

Spine

Spur

Spine = multicellular, immovable seta

Spur = multicellular, movable seta

Trichogen cell

gland cell that secretes the body of the seta

tormogen cell

gland cell that secretes the socket in which the seta moves

chemical structures of the chitin

similar to the structure of cellulose

Physical properties of chitin

* insoluble in water, ether, organic solvents, and weak acids sch as acetic acid
* soft and flexible

Resilin

arthropodin

scleotin

proteins found in the cuticle

* resilin provides elasticity
* Arthropodin convents to sclerotin
* sclerotin gives rigidity to exoskeleton

Suture

An external groove marking the line of fusion between two distinct plates of the body wall or an external line marking the invagination of the body wall

Tentorium

An apodeme found in the head that serves as a brace and attachment points for muscles

Apodeme

The ingrowth of the body wall to form an internal structure to which muscles attach and body strengthened

Conjunctiva

A membrane between two sclerites

Sclerites

Any plate of the exoskeleton bounded by a membrane or suture

molting

The process of forming the new cuticle

ecdysis

the process of mechanically removing the old cuticle

Enzymes involved in molting

* Chitinase
* proteinase

apolysis

the first step in molting when the cuticle separates from the epidermis

% of old cuticle used to create new cuticle

85%

Sequence of steps in molting

1. cuticle separate from the epidermis (apolysis)
2. Epidermal cells secrete enzymes
3. most of the endocuticles dissolved
4. epidermal cells multiply
5. new cuticle ( the procuticle) is secreted by the epidermis
6. 85% of old endocuticles used to form the new cuticle
7. the old cuticle splits and the insect emerges from the old cuticle
8. melanization and sclerotization occur

Melanization

coloring of the new cuticle

Sclerotization

Hardening of the old cuticle

procuticle

consists of exocuticle and endocuticle but no the epicuticle

Three major tagmata of the insect body

* head
* thorax
* abdomen

Vertex

frons

clypeus

gena

Areas of the incest head

* vertex = top of the head
* frons = face of the head
* gena = the side of the head or “cheeks”
* clypeus = below frons

Epicranial stem (suture)

weak area of the exoskeleton on top of the head that splits during ecdysis

1. frontoclypeal suture
2. clypealabral suture

1. a suture that separates the frons from the clypeus
2. a suture that separates the clypeus from the labrum

1. ocellus
2. stemmata

1. simple eyes ranging from 0 to 3
2. clusters of simple eyes found on caterpillars

1. hypognathous
2. prognathous
3. opisthognathous

1. mouthparts positioned at right angles to the body
2. mouthparts directed forward
3. mouthparts directed posteriorly

mandibles and parts of the mandible

found in insects with chewing mouthparts, consists of molars and incisors. Modified in other mouth types

parts of the maxilla

* cardo
* stipes
* galea
* lacinia
* palpus

parts of the labium

* mentum
* submentum
* glossa
* paraglossa
* palps

stylets of the piercing-sucking mouth type of blood feeding insects

six styles

* 2 mandibular
* 2 maxillary
* 1 labral
* 1 hypopharyngeal stylet
* labium forms the proboscis
* salivary duct found in hypopharynx
* food channel found between hypopharynx and labrum

Stylets of the piercing-sucking mouth type of plant feeding insects

four styles

* 2 mandibular
* 2 maxillary
* labium forms the proboscis
* salivary duct and food canal formed by the maxillary stylets

Parts of the siphoning mouth type of moth, butterflies, skippers

Galea of the maxilla fit together to form the siphon. Labal palp large

Parts of the sponging mouth type of the house fly

* labium forms the proboscis which terminates in a sponge-like labella
* hypopharynx contains the salivary duct
* the labrum covers the proboscis and food canal formed by the maxillary stylet

parts of the chewing-lapping mouth type of honey bee

small labrum, glossa forms the proboscis, mandibles spatula-like, large galea, paraglosa small

Parts of the antenna

* scape
* pedicel
* flagellum

Functions of the antenna

* olfactory
* tactile
* auditory or some combinations of the above

ommatidium

functional unit of the compound eye

facet

one of the lens-like divisions of the compound eye. facet normally 6-sided

number and function of ocelli

simple eye, normally 0 to 3 in number, detects light and dark

components of the dioptric apparatus

* corneal lens
* crystalline cone
* pigment cells

components of the receptor apparatus

* rhadbom
* retinular cell
* optic nerve