Why do Moths Fly Around Lights?

Why do moths fly around lights?

At night many insects fly toward light.

It’s an important question for entomologists and other ecologists, who often collect moths using ‘light traps’.

There are many assumptions and hypothesis framed.

a) Moths are not attracted to light says a study. They navigate by light, operating under the assumption that the main source of light is far, far away says a study. But if the light is a nearer source,  keeping that on its left-hand side will make the moth fly in circles.

b) Moths use the moon to navigate and mistake lights at night as the moon.  So they will either spiral in or spiral away from the moon while trying to fly in a straight line.  This is mistakenly interpreted as ‘moths being attracted to light’ (many different insects similarly navigate by the moon at night).

 

When moths fly at night they are attracted by light.

As they fly nearer the source of the light, it seems to be stronger in one eye than it does in the other.

They keep turning in the direction where they feel the light strongest. That’s why they fly towards a light in circles or spirals.

But when it is bright outside at night, as when there’s a full moon, or when it is windy, many of these insects do not gather around the light.

Image result for moths are attracted to light

 

PHOTOTAXIS:

Nocturnal insects are those which are active at night and rest during daytime. These nocturnal insects are attracted towards light which is a response called phototaxis—-Response to light.

Movement of their wings is influenced by the strength of the light.

When the light reaches both eyes with equal intensity, as from a distant source such as Moon, the insect can fly in a straight line with both wings moving the same way.

But light coming from a closer source, such as an electric bulb or candle flame is perceived more strongly by one eye than the other.

As a result of this, the wings on one side are stimulated to move faster , causing the insect to approach the light source in a spiral path and fly right into light.

Some types of moths are also known to migrate, and it’s possible that the night sky gives them navigational clues.

References:

https://www.quora.com/

https://www.sciencefocus.com

Thanks to

Insect World-Time-life books, Gakken Co., Ltd.

Who needs more food? Plants or Animals

Do Plants  need more food or animals? Why?

 

  • Plants are the primary producers.
  • Plants make more of their own food but animals do not.
  • Both plants and animals need food to perform all the life activities.
  • Every living thing has do do the life activities like growth, respiration, reproduction, etc.

 

Image result for animals

 

Animals require more energy than plants.
This is due to various reasons.

Some are :
1) Animals are motile organisms, i.e.  they move around, which burns energy whereas plants are non-motile, pretty stationary and make their own food. Being motile requires more energy.

2) Plants have many dead tissues whereas this is not in the case of animals. Hence, again animals need more energy.

 

Irony:

  • It always depends what animal you are comparing to what plant
  •  what your definition of food is.
  • A large tree would surely suck up more nutrients from the ground than a tiny insect.
  •  probably it could be that plants need less food because they can produce their own sugars through photosynthesis.
  • whereas  food is the animal’s only source of energy.

Related image

 

 

 

 

 

Dispersal-Some fruits are dispersed by water

The fibrous husk traps the air and enables the fruit to float on water.

 

Fruits dispersed by water usually float and are carried along rivers, streams or at sea.

They often have waterproof coverings or fibrous husks to help them float in water.

Example: coconut,  lotus plant,  mangrove.

Doc2

 

Dispersal of fruits and seeds:

-In order for seeds to grow at a suitable place, they must be scattered. Why is that so?

– When the seeds grow too closely together, overcrowding might occur.

-So the young plants may not get enough water, minerals and sunlight to grow well.

-The scattering of seeds or fruits is called dispersal.

-Plants that grow near or in water usually disperse their fruits or seeds by water.

-The fruits and seeds are able to float on water as they have special structures such as a  fibrous husk or air filled spaces.

-The above picture shows the fruit of a  coconut. Other fruits dispersed by water include the water lily, lotus, sea-almond and mangrove.