Morphology Flashcards
Exoskeleton
An external skeleton. Hard or soft (adults harder)
Made up of a series of plates connected by sutures that make the body flexible
What do you call the outer layer of the exoskeleton?
Cuticle
Costed with wax to prevent water intake and loss
List 4 Purposes of the Exoskeleton
- Supports the weight of the body
- Protects the body from a minor injury
- Provides internal attachment points for muscles
- Acts as a barrier against some chemicals
Muscular System
- Most muscles attach to the inside wall of the exoskeleton
- These muscles control movement: mouthparts, legs and wings
- Air through the trachea
- Food through the digestive system
- Muscle activity is controlled by the nervous system
Respiratory System
- Insects breath through the spiracles
- Easily seen in caterpillars
- Some aquatic insects such as dragonflies breath through gills underwater
Circulatory System
Insect bloos (90% liquid) runs down their back. Closest internal system to the exoskeleton OPEN CIRCULATORY SYSTEM Blood travels through some blood vessels then dumps into open cavity
Insects have a ____ blood vessel that serves as their heart
Dorsal
What does insect blood do?
- Deliver nutrients
- Collects waste
- Moves chemicals that are important for growth
Digestion System
- Most insects digest carbohydrates, proteins and fats.
- Some insects (termites and decomposers) have microorganisms in their gut to digest cellulose or other materials for them to use as nutrients
Digestive (Excretory System)
Similar to the kidneys, removes wastes from blood and digestive systems. Filters out water for recycling through the body.
Reproductive System
- Most insects species have males and females that may or may not look the same.
- Females tend to be larger than males because of creating and storing eggs
- Some insects (honeybees) can control the gender of offspring
Reproductive System
- Most insects species have males and females that may or may not look the same.
- Females tend to be larger than males because of creating and storing eggs
- Some insects (honeybees) can control the gender of offspring
Parthenogenesis
Reproducing without mating
All offspring are produced by one female and are genetically identical (aphids)
What is a potential problem of parthenogenesis?
increases the likelihood of a pest population developing resistance to some insecticides. Higher chance of a mutation resistance birthing a huge population of offspring.
Nervous System
- Insects have a ventral nerve cord with a collection of nerve cells that compose a “brain”
- collect and transmit sensory information such as temp, light, chemicals, etc
- Control the insect’s responses (movement, molting, eating, etc) Sense predator-sent to brain-movement controlled by brain
Neurotoxins
- Some insecticides affect movement of nerve impulse
* Cause nerves to fire continuously resulting in muscle paralysis
Hormone
a chemical formed in an organ or tissue of the body and travels through the body where it causes some effect on another body part
*Some hormones control: Molting, Growth and maturation to adulthood
With few exceptions only ______ insects grow
Immature
In order for an insect to grow it has to_____
Molt
Metamorphosis
A change in form. Insects go through different life stages during metamorphosis
Stage
a distinct period in development of an insect (egg, larve, pupa, adult)
Instar
- the insect’s form in between molts.
- Usually designated by numbers (ex: 3rd instar)
- Knowing what instar the pest is can be important for control (older/larger may be harder to kill)
What are the 3 life stages?
Egg, Immature (nymphs or larvae), and adults
Egg
most insects deposit their eggs singly or in clusters. Some insects (aphids) deposit live immatures
