week 7 - insect body morphology Flashcards
body morphology
Within the basic body plan, many structures have…
… become adapted to perform specific functions
body morphology
These adaptations have occurred in both…
… adult and juvenile insects
body morphology
Adaptations have occurred in…
… mouthparts, legs, wings, ovipositor, antennae and ‘whole body’ structures.
body morphology
Collembola
Collembola are ancient – now actually considered to be separate Class within Super-Class Hexapoda.
Two main groups: elongate and globular.
Habitat: soil and leaf litter (100, 000 ind/m3)
Diet: detritus
One of the most abundant macroscopic animals
< 8mm in length
< 6 abdominal segments
body morphology
legs only come off of..
thoracic segments
body morphology
furcula
folded up underneath
he ‘spring’ of springtails = Collembolan furcula
Function – to escape predators and (possibly) unfavourable environments.
body morphology
elongate collembola vs. gobular collembola
globular
Many are soil dwellers
* Furcula often reduced (some dont have it)
* Thorax and abdomen fuse
body morphology
honey bee
Sub-class: Pterygota
Division: Holometabola
Order: Hymenoptera
see notes for structure
body morphology
honey bee
legs
Distinct modifications of leg segments for pollen collection and transport.
* Pollen is collected by spines on first tarsal segment and transferred to the tibia of opposite leg – the pollen ‘basket’ for transport back to hive.
* A spur at the base of tibia on middle leg dislodges pollen masses from the basket.
adaptive advantage: more pollen in less trips (better for hive)
body morphology
Ovipositor/Sting in Bees and Wasps
Variable in structure and function in the order Hymenoptera – a series of valves.
primary function to lay eggs
body morphology
Ovipositor/Sting in Bees and Wasps
Hymenoptera has two sub- orders:
Symphyta (e.g. sawflies) – some valves are adapted to saw/cut into plant tissues and wood for egg laying
(eggs less visible, environment protected)
Apocrita Parasitica
*Function: ovipositor pierces host to deposit eggs. *Can be very long to limit proximity to host
body morphology
Ovipositor/Sting in Bees and Wasps
Hymenoptera: Bees
what if ovipositor lost?
Ovipositor is modified as a sting and egg laying function is lost
body morphology fleas
Division: Holometabola
Order: Siphonaptera
- External parasites feed on blood
Some well known flea species include: * Cat flea (Ctenocephalides felis), - Dog flea (Ctenocephalides canis),
- Human flea (Pulex irritans),
- Northern rat flea (Nosopsyllus fasciatus),
- Oriental rat flea (Xenopsylla cheopis) – Black Death.
*Need blood meal before capable of reproduction
body morphology fleas
adaptations
- Tube-like mouth-parts adapted to feeding on the blood of their hosts.
- Bodies are laterally compressed permitting easy movement through the hairs or feathers.
- Legs are long, the hind pair well adapted for jumping (around 200 times their own body length)
- Body is hard, polished, and covered with many hairs and short spines directed backward, which also assists its movements on the host.
- Tough body is able to withstand great pressure, likely an adaptation to survive scratching etc
body morphology
click beetles
Sub-class: Pterygota
Division: Holometabola
Order: Coleoptera
body morphology
click beetles
‘click’ mechanism
- Function: to regain normal walking position when tipped over or fall from plants onto back (and deter predators if on back).
- A ‘spine on ventral surface projects back into cavity on the mesothorax.
- Spine pushes quickly into cavity (click noise) and beetle ‘rolls’ to one side and can move onto legs.
body morphology
sound production and hearing sound
e.g. Preying Mantis (Order: Mantodea)
The praying mantis has one ear (eardrum), located on the ventral side of the abdomen, between the four trochanter of its hind legs. Detects echolocation calls of bats
Delicate hindwings, camouflage markings on the heavier protective forewings. Many have a pair of dots on their wings which simulate a pair of eyes for defensive posturing. When defending, the mantis may rear up and wave its forelegs while simultaneously rattling its wings together to create a hissing noise
body morphology summary
Great diversity of specialized morphological adaptations in insects
* Collembolan furcula - jumping
* Bee legs – pollen collect and transport
* Click beetles – righting mechanism
* Ovipositor – sawing, piercing, stinging
* Fleas – body shape, hair arrangement
* Sound production (and detecting sound)
Provide many clues to understanding the biology/life style of an insect
body morphology
sound production
Tremulation (vibration) –
e.g. species specific flight sounds
body morphology
sound production
Percussion –
e.g. Cicadas (Order: Hemiptera)
Special organ called a tymbal)
body morphology
sound production
tridulation (frictional mechanisms) –
widespread (at least 7 orders), e.g. Crickets (Order: Orthoptera)
