BIO2231 - Arthropoda IV - Hexapods Flashcards
<p><span>Class Insecta</span></p>
<p><strong><span>Subclass Pterygota</span></strong></p>
<p>2 points.</p>
<ul><li>Two pairs of wings: adult stages of almost all orders have wings </li><li>Grouped based on wing function</li></ul>
<p><span>BIO2231 9aa</span></p>
<p><span>Class Insecta: Subclass Pterygota</span></p>
<p><strong><span>Infraclass Paleoptera</span></strong></p>
<p><span>Oldest group</span></p>
<div>Mayflies (Order Ephemeroptera) </div>
<div>Dragonflies (Order Odonata)</div>
<ul> <li>Wings thought to be most similar to the ancestral condition - unable to be folded</li></ul>
<p><span>BIO2231 9ab</span></p>
<p><span>Class Insecta: Subclass Pterygota</span></p>
<p><strong><span>Infraclass Neoptera</span></strong></p>
<p><span>Modern insects</span></p>
<div>Everything apart fro Maflies & Dragonflies</div>
<p><span>BIO2231 9ac</span></p>
<p><span>Describe</span></p>
<p><strong><span>Pterygota</span></strong></p>
<p>5 points.</p>
<p><span>Neoptera - new wings</span></p>
<ul> <li>Wings folded when the insect is at rest</li> <li>Includes all other orders</li> <li>Divided into two groups based on development pattern</li> <ul> <li>Hemimtabola: Polyneoptera + Condylognatha</li> <li>Holometabola: Holometabulous</li> </ul></ul>
<p><span>BIO2231 9ad</span></p>
<p><span>Infraclass Neoptera</span></p>
<p><strong><span>Polyneoptera</span></strong></p>
<p>6 points.</p>
<p><span>Grasshoppers, mantids, termites, earwigs, cockroaches, stoneflies</span></p>
<ul> <li>2 pairs of wings</li> <li>Biting mouthparts</li> <li>Herbivores and predators</li> <li>Outside wings</li> <li>Hemimetabolous development:</li> <ul> <li>Development through a series of "nymphs" which are progressively more like the adult form</li> </ul></ul>
<p><span>BIO2231 9ae</span></p>
<p><span>Infraclass Neoptera</span></p>
<p><strong><span>Condylognatha</span></strong></p>
<p>3 points.</p>
<p><span>Aphids, cicada and backswimmers</span></p>
<ul> <li>Piercing and sucking mouthparts</li> <li>Plant feeders / predators</li> <li>Hemimetabolous</li></ul>
<p><span>BIO2231 9af</span></p>
<p><span>Subclass Pterygota</span></p>
<p><strong><span>Holometabola</span></strong></p>
<p>3 points.</p>
<ul><li>Inside wings </li><li>Holometabolous development :Larvae undergo a complete change from larva through to a pupal stage to an adult </li><li>Complete metamorphosis</li></ul>
<p><span>BIO2231 9ag</span></p>
<p><span>Examples of Holometabola</span></p>
<p><strong><span>Order Lepidoptera</span></strong></p>
<p>5 points.</p>
<p><span>butterflies and moths</span></p>
<ul><li>Wings covered in scales </li><li>Active larvae </li><li>Modified mouthparts: proboscis </li><li>Large compound eye </li><li>Antennae present, butterflies have clubbed antennae</li></ul>
<p><span>BIO2231 9ah</span></p>
<p><span>Examples of Holometabola</span></p>
<p><strong><span>Order Coleoptera</span></strong></p>
<p>4 points.</p>
<p><span>Beetles</span></p>
<ul><li>Two pairs of wings </li><li>Fore wings modified into protective elytra </li><li>Mandibulate mouthparts: biting & chewing </li><li>Antennae present in range of forms</li></ul>
<p><span>BIO2231 9ai</span></p>
<p><span>Examples of Holometabola</span></p>
<p><strong><span>Order Diptera</span></strong></p>
<p>5 points.</p>
<p><span>Flies and mosquitos</span></p>
<ul><li>One pair of wings </li><li>Hind wings modified into halters </li><li>Compound eyes </li><li>Sucking and piercing mouthparts </li><li>Short simple antennae</li></ul>
<p><span>BIO2231 9aj</span></p>
<p><span>Examples of Holometabola</span></p>
<p><strong><span>Order Hymenoptera</span></strong></p>
<p>6 points.</p>
<p><span>Ants, bees and wasps</span></p>
<ul><li>Two pairs of wings </li><li>Fore and hind wings hooked (short) </li><li>Chewing mouthparts </li><li>Compound eyes </li><li>Modified ovipositor </li><li>Sociality</li></ul>
<p><span>BIO2231 9ak</span></p>
<p><span>Insects - Incredible numbers</span></p>
<p><strong><span>Arthropods</span></strong></p>
<p><span>Make up >80% of all animal species</span></p>
<p><span>BIO2231 9al</span></p>
<p><span>Insects - Incredible numbers</span></p>
<p><strong><span>Hexapoda</span></strong></p>
<p><span>Make up ~90% of arthropods</span></p>
<div>> 70% of all animal species</div>
<p><span>BIO2231 9am</span></p>
<p><span>Insects - Incredible numbers</span></p>
<p><strong><span>Endopterygotes</span></strong></p>
<p><span>Make up 88% of insects</span></p>
<div>> 60% of all animal species</div>
<p><span>BIO2231 9an</span></p>
<p><span>Insects - Incredible numbers</span></p>
<p><strong><span>Beetles</span></strong></p>
<p><span>Make up 45% of insects</span></p>
Every third animal species is a beetle!<p style="text-align:right;"><span>BIO2231 9ao</span></p>
<p><span>Insects - Incredible numbers</span></p>
<p><strong><span>Ants and termites</span></strong></p>
<p><span>Make up 33% of terrestrial animal biomass?</span></p>
<p><span>BIO2231 9ap</span></p>
<p><span>Beetles</span></p>
<p><strong><span>Why so successful?</span></strong></p>
<p>3 points.</p>
<ul> <li>Diversity of resources</li> <li>Resistant to predation</li> <li>Aided by plant defenses like sap, poisons</li></ul>
<p><span>BIO2231 9aq</span></p>
<p><span>Class Insecta - Features</span></p>
<p><strong><span>Mouthparts</span></strong></p>
<p>11 points.</p>
<ul> <li>Complex food handling apparatus</li> <li>Implication of reduction of number of walking legs</li> <li>Many modifications of structure</li> <li>6 Head segments (head is tagmatised)</li> <ul> <li>3 Pregnathal</li> <li>3 Postgnathal</li> </ul> <li>Food handling</li> <li>Food tasting</li> <li>Cutting/sucking</li> <li>Highly modified in some groups</li> <ul> <li>Access to wide range of food types</li> </ul></ul>
<p><span>BIO2231 9ar</span></p>
<p><span>Class Insecta - Features</span></p>
<p><strong><span>Locomotion</span></strong></p>
<p>9 points.</p>
<ul> <li>Fast</li> <li>Coordinated</li> <li>Versatile</li> <ul> <li>Walking</li> <li>Climbing</li> <li>Running</li> <li>Jumping</li> <li>Swimming</li> <li>etc.</li> </ul></ul>
<p><span>BIO2231 9as</span></p>
<p><span>Class Insecta - Features</span></p>
<p><strong><span>Locomotion - wings</span></strong></p>
<p>7 points.</p>
<ul> <li>Flight possible via:</li> <ul> <li>Organised muscle system</li> <li>Rapid metabolic rate</li> <li>Small size</li> <li>Flexible thorax</li> <li>Complicated hinge system at wing base</li> </ul> <li>Wings linked to success on land</li></ul>
<p><span>BIO2231 9at</span></p>
<p><span>Class Insecta - Features</span></p>
<p><strong><span>Nervous Systems</span></strong></p>
<p>7 points.</p>
<ul> <li>Typical arthropod system</li> <ul> <li>Segmental ganglia</li> <li>"Brain around gut"</li> <li>Supraoesophageal ganglion</li> <li>Suboesophageal ganglion</li> </ul> <li>Ganglia fusion in ventral nerve cord</li> <li>6 Neuromeres</li></ul>
<div>1: protocerebrum</div>
<div>2: deutocerebrum</div>
<div>3: tritocerebrum</div>
<div>4, 5, 6: Mouthparts</div>
<p><span>BIO2231 9au</span></p>
<p><span>Class Insecta - Features</span></p>
<p><strong><span>water balance</span></strong></p>
<p>4 points.</p>
<ul> <li>Adaptations to prevent desiccation and reduced water loss from excretion</li> <li>Linked to success on land</li> <ul> <li>Waxy coating to exoskeleton (true for all arthropods)</li> <li>Malpighian tubules</li> </ul></ul>
<p><span>BIO2231 9av</span></p>
<p><span>Class Insecta - Features</span></p>
<p><strong><span>Respiration</span></strong></p>
<p>6 points.</p>
<ul> <li>Network of tubes (tracheal system)</li> <ul> <li>Not as extensive in spiders</li> <li>Evolved independently in insects and spiders</li> </ul> <li>Oxygen delivered to cells</li> <li>Rapid movement (and flight)</li> <li>Linked to success on land (arthropods generally)</li></ul>
<p><span>BIO2231 9aw</span></p>
<p><span>Class Insecta - Features</span></p>
<p><strong><span>constraints on body size</span></strong></p>
<p>4 points.</p>
<ul> <li>Trachea - not efficient in large bodies</li> <li>Molting</li> <ul> <li>Large crustaceans? supported by water but not so on land</li> </ul> <li>Advantages of small size</li></ul>
<p><span>BIO2231 9ax</span></p>
Class Insecta - Features
Life cycle (metamorphosis)
4 points.
Related to mode of growth and exoskeleton
- Egg: protective stage
- Larvae: feeding and growth
- Pupae: protection for transitional stage
- Adult: reproduction, dispersal and occupation of different niche
BIO2231 9ay
Insects - Behaviour
7 points.
- Diverse life histories
- Complex signalling
- Specialisation
- Learning
- Orientation behaviour
- Swarming
- Social behaviours
BIO2231 9az
Class insecta: Feeding ecology
- Saprophagy
- Hematophagy / parasites
- Predation
- Parasitoids
- Phytophagy
BIO2231 9ba
Class insecta: Feeding ecology
Saprophagy
6 points.
- Dead, decaying, organic material
- Major role in decomposition
- Plants, carrion, feces, microorganisms
- Eg. Thysanura (bristletails)
- Eg. Blattaria (Cockroaches)
- Eg. Diptera (Flies, Mosquitoes)
BIO2231 9bb
Class insecta: Feeding ecology
Hematophagy /parasitism
6 points.
- Parasites
- Do not kill host
- Usually only one life stage
- Eg. Siphonaptera (Fleas)
- Eg. Diptera (Flies, mosquitoes)
- Eg. Phthiraptera (Sucking lice)
BIO2231 9bc
Class insecta: Feeding ecology
Phytophagy
7 points.
- Plant tissues, pollen, nectar, etc
- Major selective pressure in plant and insect evolution
- Generalists and specialists:
- Eg. Orthoptera (grashoppers etc.)
- Eg. Hemiptera (true bugs, aphids, cicadas)
- Eg. Lepidoptera (moths)
- Eg. Coleoptera (beetles
BIO2231 9bd
Predation/Parasitoidism
8 points.
- Predators other insects
- Hunters, stalkers
- Parasitoids: Larvae develop inside
- Major role in population control
- Often specialised
- Some Hymenoptera
- Some Diptera
- Hyperparasitoids
BIO2231 9be
Coevolution arms race
9 points.
- Plant-insect interactions drive evolution of both taxa
- Plant defences
- Mechanical
- Chemical
- Insect response
- Special mouthparts
- Behavioral
- Detoxification, sequestration
- Host specialisation
BIO2231 9bf
Coevolution symbiosis
5 points.
Flower/Insect Interaction
- Main pollinator species
- Flower acts as shelter, food and protection
- Significant role of insects in determining
- Flower structure
- Distribution
BIO2231 9bg
