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continuously or semi-continuously do egg-laying most often along the year. Worm eggs are

placed in the cocoon. The cocoon shape is different depending on the species of worm. In moist
conditions and the temperature of 16 to 27 ° C for the eggs, within 14 to 20 days the small

worms come forth. Natural life of many earthworms is short and some species in case of being
protected from natural hazards live longer more than 1.5 Year.

Activity, metabolism, growth and reproduction of worms are strongly affected by the

temperature. Temperature and humidity usually have an inverse relation. High temperature and
dry environment are more limiting than low temperatures and water saturated environment, for

the worms. Earth worms setting cocoon and coming out of egg are also affected by temperature.
For example, setting cocoon in Eisenia fetida increases linearly with increasing temperature

from 10 to 25 ° C, although the number of worms per cocoon out in 25°C is less than 20 °C.
Cocoon opening period also is depends on temperature. Growth of new worm out of the eggs

to mature at 18 ° C reaching in 9.5 weeks and at 28 ºC only 6.5 weeks is needed.

Worms are sensitive to hydrogen ion concentration which is stated as pH. According to
sensitivity to pH in some texts have been divided them in three categories: resistant to soil

acidity, sensitive and to soil acidity and a variety that can live in wide range of pH. However,
many researchers have expressed that more species of earthworms show interest to live in

neutral pH. Eisenia fetida is preferred life in the soils that pH is between 6.5 and 7.5. The role

of organic carbon and inorganic nitrogen for synthesis of cell, growth and metabolism is
essential in all organisms. Proper ratio of carbon to nitrogen is needed for optimal growth of

earthworms [17, 37].

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