entomology species quiz 1

Labrum

Forms pre oral cavity

Covers base of mandibles

hypotharynx

Tongue-like structure

Objects forward from back of preoral cavity

Mandibles

Jaws

Apical portion→ cutting

Base→ grinding

Maxillae

Helps mandibles process food

Inner most portion→ lacina (helps macerate food)

Galea and maxillary palps

Sensory covered in setea w/ mechnoreceptors and chemoreceptors

Labium

Bottom of preoral cavity

2 regions:

• proximal prementum (floor)

• Labial palps (sensory)

What are the potential functions of the cuticle?

Protection

Mate attraction

Muscular attachment

Protection against foreign molecules

Act as metabolic reserve

Repository for hormones/pheromones

Cuticle

=exoskeleton

Secreted by epidermis

Made up of epicuticle and procuticle

(Lining trachial tubes, fore & hind guts, coat gland ducts)

Epicuticle

Secretes cuticle

Made up of cement layer, wax layer,

Outer epicuticle, inner epicuticle

Cement layer

Outer hardened protective layer

Wax layer

Lipid layer

Hydrophobic, made of hydrocarbons/fatty acid chains

Outer epicuticle & inner epicuticle

Produce some waxy layers

Procuticle

Made up of exocuticle, endocuticle, and mesocuticle

Exocuticle

Strong, more inflexible region, made up of many layer of chitin, scleritized region, makes proteins water insoluble

Endocuticle

Hundreds of layer of chitin, strength from H bonds

Mesocuticle

When there isn’t a clear indistinction between end/exocuticle

Should the cuticular structure and composition be the same in all insects?

No

Should the cuticle structure and composition be the same in all regions of an insects body?

No

What regions of an insects body may need increased flexibility

Joints

Between segments

Wings and bases

Neck

Sensory regions

Abdomen (respiration, feeding, reproduction)

Cuticular outgrowths

Spines, horns, spurs, setae

Spines/horns

Immovable

Spurs

Moveable

Setea

Hairs, microtrchia, trichoid sensilla sensory and glandular

What structure is this?

Horn, immovable cuticular outgrowth

What structure is this?

Spurs, moveable cuticular outgrowth

What structure is covering this insect?

Setae, sensory/glandular cuticular outgrowth

Cuticular ingrowth

• serve as points for muscle attachments

• Serve as structural support

Physical coloration

Reflect/diffract whole wavelength of visible light

Result of light scattering,interference, and diffraction

Pigmentary colors

Absorption of visible light by a range of chemicals

In what ways can pigment form?

1. Insect metabolism

2. From food source

3. Microbial symbiotes

Why is coloration important?

Camouflage

Aposematism (warning/mimicry)

Thermoregulation and/or UV protection

Startle/distract

What are the 2 openings in head structure?

Occipital foramen (allows for connection to thorax)

Oral opening

What are the fused segments in a head structure? Which ones are preoral or post oral?

Preoral

• preantenal-protocerebral

• Labral

• Mandibular

• Antennal

Post oral

• maxillary

• Labial

Hypognathus

Ventral mouth orientation

Prognathus

Anterior mouth orientation

Opisthognathus

Posterior mouth orientation

Which mouth orientation is this?

Opisthognathus

Which mouth orientation is this?

Hyponathus

Which mouth orientation is this?

Prognathus

Sutures

Show remnants of segmentation

Ecdysal lines

Grooves that reflect internal structures

Tentorium

Ingrowths of cuticle

2 major sets of arms

Help race cranium and provide muscular attachment

Key features of hexapoda

6 legs

3 tagma

• head/cephalon

• Thorax

• Abdomen

5 wingless classes/orders

Protura

Collembola

Diplura

Archaeognatha

Zygentoma

Why would the evolution of wings be advantageous?

Escape prey

Better dispersal

Access to different populations

Label the 3 tagma

Head- cephalon

Middle- thorax

Bottom- pygidium (anus)

Chelate

Pincher like morphology

Subchelate

Spider fangs