Locomotion, water, air and land

Tripod stance

Stance with 6 limbs where there is 2 groups of opposite legs. 1 group is retracting and the other is protracting.

Retraction

Opposite side legs thrusting rearwards

Protraction

Opposite legs moving forwards

Tenant hairs

 adhesive setae/hairs help grab onto whatever. They have many different shapes to affect the contact area.

maggots moving

Do not have legs so they drag themselves along by sticking out their heads anchoring it to the ground and then pulling themselves along. Then there is a wave of contraction from head to tail. Push body forward and then pull body to shorten. They move forward. This is assisted by different adaptations such as head hooks, band of spines, etc… that grip the substrate. 

Crawlign underwater

 Occurs underwater on solid substrate. It is alternate gripping with prothoracic and abdominal pseudopods. They crunch/bend but do not contract. They can crawl backwards due to the cycle that they take. Species specific

Crawling caterpillar

• 3 simple, paired, jointed thoracic legs; these are called proper legs.

• Everything else is a proleg which are simple cuticular hollows filled w/ fluid. Different species will have different # of legs + different areas. They will have hook-like crochets w/ retractor muscles.

Resilin

A rubber-like or elastic protein in some insect cuticles.

Froghoppers/Auchernorrhyncha

• THe é is stored in the coxa-trochanteral joint. 

• The leg reels in the leg to put on tension like a catapult. Released like a catapult as well. 

• Slow contraction leads to the storage of energy. 

• The hindlimbs drag behind them due to the sheer amount of tension. 

• They can pull 400+ G’s

• Deform due to force + store more é. They reshape mid-jump.

Fleas

• Trochanterol-levator muscles: A compressed pad of resilin. 

• The tension releases very quickly

Trochanterol-levator muscles

A compressed pad of resin in fleas.

Furcula

A springing organ in collembolan it is a tail that is used like a lever to get them into the air.

Pygidial gland 

Abdominal gland that shoots hydrophobic secretions lowering the surface tension behind them. The pressure difference is what moves them. IT is found in  staphylinidae. 

Meniscus climbing technique

Found in the water lily leaf beetle. They operate like a pool noodle, they push the middle part down keeping the other parts up.

Walking underwater

They drag themselves around like terrestrial insects. Do not need to worry about resurfacing but do need to know about drifting. 

Apterygote

• non-insect hexapods and archingathos and zygentoma. 

• Primarily wingless, never evolved wings, continue to not have them

Pterygote

• First organisms evolved to fly that we know of around ~350 mya.

• Only invertebrates that fly in the true sense, active flight. 

• Truly monophyletic, evolved once. 1 single ancestor that evolved flight. 

• Huge speciation events, helped them move around access resources. Linked to speciation of angiosperms. Improved mate finding and power of dispersal. 

  • There is secondarily winglessness in almost every order. 

Paleoptera

• The earlier form of flight morphology, old wing. 

• Only found in Ephemeroptera and Odonata. 

• When wings are closed they are closed dorsally or laterally at rest. They do not fold or rotate and sit down nicely. 

• The forewings and hindwings can move independently of each other in odonata. The articulation is via axillary plates directly fused with wing veins; this is why they can't fold their wings. 

• It is monophyletic. 

• Flight is achieved through direct musculature: the wing are directly attached to muscles independently and controlled independently and directly. 

1 nervous impulse = 1 action. Flap, flap, flap, etc…

Neoptera

• new wing and newer flight morphology

• Capable to some degree of wing folding including rotation, complicated folding mechanisms. Articulation with moveable sclerites. Typically over the body at rest. This affords some protection, especially in or around the ground, and lets them fit into tighter spaces. 

• Exception: ex,butterflies

• Are articulated with mobile/moveable sclerites. 

• Main flight muscles are Indirect muscles: typically working together in flight. 

Axillary sclerites

ALong withteh humeal plate and hte tegula comprise the articular scleritess of the neopteran wing base.

• Triangle area at the base of the wing. 

• Contains mobile articular sclerites, rotate on the thorax. 

• Attached to little muscles, let wings rotate down and fold behind the body. 

• Necessity to fix wings both in rest and in flight

  • Move relative to each other by stems of joints and hinges.

Articular sclerites

separate, small, movable plates that lie between the body and a wing. Moveable sclerites. Include the humeral plate and the tegula. 

LEading edge

coastal margin of the wing. Faces anteriorly

Trailing edge

anal margin of the wing. Posterior part if held straight outO

Outer edge

apical margin, most distal from the body when held out.

Pitch

The wings rotation about the transverse axis

Pronation

Downstroke: the leading edge down. (thumbs down)

Supination 

Upstroke: the leading edge up. (thumbs up)

Synchronous flight

neurogenic muscle, 1 nerve impulse - 1 muscular contraction. Limited by the neuron's refractory period. Can't flap your wings faster than your neurons can fire. 

Neurogenic muscles

Muscles used in synchronous flight

Asynchronous flight

myogenic muscles, spontaneous muscular contraction if the structures are stretched beyond threshold allows much faster wing beats. 1 nerve impulse = several muscle contractions. + click mechanism.

Myogenic muscles

Muscles used in asynchronous flight.

Mecopteran pattern

wings are coupled so they move together as a single unit. Primitive arrangement of jugal lobe and humeral lobe.  Each has a set of sets of jugal and frenular bristles which cause enough friction from the wings from moving out of phase + the power strokes are so closely aligned. Found in scorpion flies.

Jugate coupling

Proper jugum which is a long peg that sits on top of the hindwing. Like a paperclip. 

Frenate coupling female

Lepidopteran system. It is a well developed frenulum on the hindwing; it is a stiff set of bristles engaged with a catch, retinaculum, on the underside of the forewing.

Frenate couping male

 Lepidopteran system, the frenulum bristles all fuse into one spine. The retinaculum on the forewing becomes a cuticular clasp. 

Frenulum

Spine or group of bristles on the costa of the hind wing. It works with the forewings rentinaculum. 

Rentinaculum

The specialized hook or scales at eh base of the forewing. It works with the hindwings frenulum.

Hamuli

row of very visible hooks on the leading edge of the hindwing, they catch onto a fold on the forewing. In Hymenoptera.

Aplexiform wing coupling

there is an extensive area of overlap. Creating friction keeping the wings together. Found in large butterflies

Pitch

diving or climbing, on the transversal axis

Roll

barrel roll, on the long axis of the body

Yaw

Rotation about the dorsoventral axis, ie, turning. 

Basalare

Found anteriorly to the pleural suture. It pulls the leading edge down, pronating it into the downstoke.

Subalare

Found anterior to the pleural suture. It pulls the trailing edge of the wing down at the bottom of the stroke, supinating it into the upstroke.