Insects

What is the scientific name for this subphylum?

Uniramia

What are the two things that Uniramians are characterized by?

1. 1 pair of appendages

2. Antennae that do not branch

When and where did this group evolve?

400 mya, on land

What are centipedes are millipedes characterized by?

1. Long, wormlike body

2. Many leg bearing segments

What are two things that make centipede and millipedes lose water easily?

1. They lack closeable spiracles

2. They lack a waterproof covering

Where do centipedes and millipedes live due to losing water easily?

Rocks, soil, and relatively moist areas

A centipede is a…

carnivore

A millipede is a…

detritus feeder

What do centipedes have in addition to other mouthparts? Where is is located?

A pair of poison claws in the head region used to catch or stun and kill prey

What does the diet of a centipede consist of?

Other arthropods, earthworms, toads, small snake, and even mice

How many legs do centipedes have per body segment? Are there legs on every body segment?

1 pair of legs per body segment, excluding the first segment (claws) & the last 3 (legless)

How is each millipede segment formed? What does this mean in terms of legs per body segment?

From the fusion of two segments in the embryo, thus allowing for two pairs of legs per segment (twice as many as centipedes)

What do millipedes feed on? What does this make them?

Decaying and dead plant material, making them detritus feeders

What are two ways in which millipedes protect themselves?

1. Rolling up into a ball to protect their softer undersides

2. Secreting unpleasant/toxic chemicals

What do insects extremely vary in?

Body shape and habits

What are the two things that insects are characterized by?

1. A 3 part body divided into the head, thorax, and abdomen

2. 3 pairs of legs attached to the thorax

What does an insect have in addition to its two main characteristics?

1. A pair of antennae

2. A pair of compound eyes on the head

3. Two pairs of wings on the thorax

4. A system of tracheal tubes for respiration

What are used as mouthparts in insects?

The 3 pairs of appendages, including a pair of mandibles

How do grasshoppers use their mouthparts to eat food?

Mouthparts are designed to cut and chew food into a fine pulp

How does a female mosquito use its mouthparts to eat food?

Mouthparts are modified into a sharp tube to pierce skin in order to drink blood

How does a butterfly use its mouthparts to eat food?

Mouthparts are fused together to form a long tube used to suck nectar

How does a bee use its mouthparts to eat food?

Mouthparts are modified for chewing and gathering nectar

How do flies use their mouthparts to eat food?

Their spongy mouthparts are used to soak up food

What are the legs of insects often equipped with?

Spikes or hooks to hold onto things or for defense

What can the legs be adapted for in addition to walking?

Jumping or capturing and holding prey

What are the flying abilities of a butterfly?

They fly slowly with limited maneuverability

What do the flying abilities of some bees, flies, and moths?

Excellent maneuverability, quite fast

In flying insects, what is most of the space in the thorax taken up by?

Large muscles which operate the wings.

What is the enormous amount of energy needed for flying wings supplied by?

Oversized mitochondria

What do the wing muscles in many insects have? What does this retain, and what does this mean for their flying muscles?

1. They have a special blood supply that helps retain heat produced by muscle activity

2. This means that their flying muscles are kept warmed than the outside temperature, allowing them to operate efficiently even when it is cold outside.

Insect society

A special type of colony that many insects form in where seperate individuals are dependant on one another for survival.

What can insect societies range from, in terms of size?

half a dozen to 7 million individuals

What are insects which live in societies called? Examples?

Social insects. Examples include bees, wasps, ants, and termites

What are castes in insect societies?

Types of individuals in insect societies who have specialized bodies for its functions, making them different from other castes

What are the 3 bsic castes?

1. Reproductive males

2. Reproductive females

3. Workers

Division of labour

Different individuals performing different tasks necessary for the survival of the colony.

What are reproductive females known as? Typically, how many are there in an insect society? How big are they relative to others?

1 queen, the largest individual

How many eggs can a termite queen lay up to in a day?

30,000

What is the role of the reproductive male?

They serve to only fertilize the queens eggs.

Describe the variation of roles that reproductive males undertake.

1. Some stay with the queen as a permanent member of the colony

2. In other colonies, the queen recieves alll the sperm she needs after 1 or a few mates

What are the two fates of the male reproductive worker?

1. Sucessful males die after mating

2. Unsucessful males are ejected from the colony

List the vareity of tasks that the workers perform in colonies

1. Care for the queen, eggs, and young

2. They are incharge of gathering, storing, and even growing food

3. They are incharge of building, maintaining, and defending the colony’s home

What genders are the workers in ant, bee, and wasp societies?

Female only workers

What genders are the workers in termite societies?

Both female and male

Which society’s workers are capable or performing all takss?

Bees and wasps

Which society’s workers are specialized and only carry out their specific tasks?

Ants and termites

What types of signals are used in insect communication?

Sound, visual, chemical, and others

What does non social insect communication usually involve?

Finding a mate

Pheromone

A chemical released that affects the behaviour and/or development of other individuals of the same species.

Is communication more complex in non-social or social insects?

Social

What does each species of social insect have to communicate information?

a “language” in the forms of visual, touch, sound, and chemical signals

How are pheromones important in a social insect society?

Some function as short term messages, others function as long term messages which all help keep the colony functioning and in order.

What can short term messages signal in social insect societies?

They can signal alarm, death of a member of a colony, or the presence of food.

Explain how ants use pheromones to signal the presence of food, using a step by step explanation

1. Worker ant finds food, goes back to the colony

2. In doing so, the worker ant drags its abdomen on the ground, leaving behind pheromones

3. Its nestmates can use sensory hairs on their antennae and follow the trail of pheromones to get food.

How does a queen honeybee use pheromones as a longterm control over her colony?

1. Queen honeybee produce a pheromone called “queen substance”

2. Queen substance ensures that there is only 1 queen in control

Queen substance functions (3)

1. Prevents the development of rival queens

2. Worker bees are unable to lay eggs

3. Female larvae are raised as workers, not as queens

What happens if there is a low amount of the queen substance in a colony?

Worker bees will feed female larvae a special diet, causing them to develop into queens

What are the two basic dances that honeybees communicate in?

1. Round dance

2. Waggle dance

Describe the movement of the round dance

A bee which has found food will first circle one way, and then the other, over and over again.

What does the round dance in bees signal?

That there is a source of food within 50 meters of the hive.

What does the frequency of which the dancing bee changes direction indicate? (Round dance)

The quality of the food source - the more frequent the change in direction, the greater the energy is of the source of food.

How can a bee determine what kind of flower the round dancer bee has found?

By smelling the dancer with their chemical receptors on their antennae.

Describe the movement of the waggle dance.

A bee which has found food will run forwards in a straight line while waggling her abdomen, circle one way, run in a straight line again, then circle the other way (similar to a figure 8)

What does the waggle dance indicate?

That the dancing bee has found food more than 50 meters away from the hive.

Where is most of the information about the food conveyed in the waggle dance?

The straight run - the longer the bee runs straight and the more she waggles her abdomen, the farther away the food.

What does the direction of the straight run indicate in the waggle dance?

Which direction the food is to be found, relative to the sun.