求一篇关于蝴蝶生长过程的英语作文

The butterfly is holometabolous insects,its life has four distinct developmental stages:( 1) the egg stage ( embryonic period );
( 2) the larval stage ( growth period );
( 3) the pupal stage ( period );
( 4) the adult stage ( sexual period ).
After three stages of development are collectively referred to as the postembryonic development.The four developmental stages of the body,from the morphological point of view,nothing in common.Therefore,must pass through the system or continuous observation,can understand it is a species of four developmental stages.
The four development stages of go round and begin again,forming a circle of life,also called a generation.Butterfly to complete a life time,short,short several days ( such as Pieris rapae ),better nearly three years ( Rudong North Parnassius ).In the year between the number of generations,often due to Babesia species have different.A year of one generation ( such as the Chinese tiger swallowtail ); there are many generations ( such as Pieris rapae ),its number of generations often with the temperature around the level are different,they are in Heilongjiang for one year only 2 3 generations in Guangdong,but can be up to 5 6 generations.As for generations is named,since the beginning of the year,and at the end of the year,are called the first generation,second generation ......And so on.In addition,there are seasonal and naming generation,for example :adult emergence in the spring called spring generation adult emergence in the summer,called Summer generations.