cocoon is 15
C and the time period for the hatching of cocoon also increases with an
increase in temperature (Butt 1993). Lee (1985) also observed that the optimum
temperature requirement for the growth of indigenous populations of Lumbricidae in
Europe ranged from 10 to 15
C. Satchell (1967) concluded that an earthworm
performs their best activities at night due to less soil temperature on the surface. They
can move down into the soil to escape these adverse temperature. Raja et al. (2017)
also observed the positive correlation between soil temperature and earthworm
abundance which showed that earthworm abundance increased with an increase in
temperature and vice versa. While according to Duiker and Stehouwer (2008) and
Dewi and Senge (2015), the optimum temperatures for earthworm’s growth ranged
from 0 to 35
C, Tripathi and Bhardwaj (2004) observed that earthworm can survive
best at 20
C in laboratory conditions. Lalander et al. (2015) observed that earthworm moves to the edges and top levels of vermicomposting bed if the temperature
of the vermibed is more than the threshold temperature. Edwards et al. (1998)
studied the life cycle of Perionyx excavatus in a variety of organic wastes under
various population density pressures and temperature between 15 and 30
C. They
observed that an increase in temperatures up to 30
C accelerated the growth of
earthworms but decreased the time of sexual maturity. Edwards (1998), in another
study, evaluated the optimal conditions for breeding of Eisenia fetida with different
ranges of animal and vegetable wastes under aerobic condition with a temperature
range of 15–20
C, moisture 80–90%, ammonia content <0.5 mg/g, salt content
<0.5% and pH in the range of 5–9. He found that the population density of
earthworms per unit volume or weight of waste was very important in affecting
the rate of growth and reproduction.
With an increase in temperature, the metabolism rate of the earthworm is also
increased which requires more food stock for the same. Tripathi et al. (2011) studied
the effects of varying temperatures (12–44
C) on the specific activity of cytoplasmic
malate dehydrogenase (cMDH), mitochondrial malate dehydrogenase (mMDH) and
lactate dehydrogenase (LDH) in earthworms. They concluded that the specific
activity of the above-said enzymes decreases in the earthworm with an increase in
temperature and vice versa. They also reported that this change in enzyme activity is
dependent on the ecological category of the earthworm species. They observed more
variations in the enzyme activity in earthworm with epigeic ecological nature while
less variation was observed in the endogeic ecological nature of earthworm species.
The less variation in endogeic earthworm species was due to less temperature
fluctuation within the soil.
The abundance of earthworms is very less during the winter periods which acts as
a harsh condition for earthworm survival. According to Robinson et al. (2018), there
was a decrease in the mean weight and growth in the invertebrate soil fauna with a
change in soil temperature, but the impacts of temperature on the invertebrate
population varied from species to species. Kanianska et al. (2016) observed that
no earthworm species have been reported from the sites having high soil temperature
and low precipitation. Thus, appropriate soil temperature is a limiting factor for
earthworm survival in the soil. Haokip and Singh (2012) observed that earthworm
abundance and diversity should be at a maximum level when the threshold level of
342
S. Singh et al.
C and the time period for the hatching of cocoon also increases with an
increase in temperature (Butt 1993). Lee (1985) also observed that the optimum
temperature requirement for the growth of indigenous populations of Lumbricidae in
Europe ranged from 10 to 15
C. Satchell (1967) concluded that an earthworm
performs their best activities at night due to less soil temperature on the surface. They
can move down into the soil to escape these adverse temperature. Raja et al. (2017)
also observed the positive correlation between soil temperature and earthworm
abundance which showed that earthworm abundance increased with an increase in
temperature and vice versa. While according to Duiker and Stehouwer (2008) and
Dewi and Senge (2015), the optimum temperatures for earthworm’s growth ranged
from 0 to 35
C, Tripathi and Bhardwaj (2004) observed that earthworm can survive
best at 20
C in laboratory conditions. Lalander et al. (2015) observed that earthworm moves to the edges and top levels of vermicomposting bed if the temperature
of the vermibed is more than the threshold temperature. Edwards et al. (1998)
studied the life cycle of Perionyx excavatus in a variety of organic wastes under
various population density pressures and temperature between 15 and 30
C. They
observed that an increase in temperatures up to 30
C accelerated the growth of
earthworms but decreased the time of sexual maturity. Edwards (1998), in another
study, evaluated the optimal conditions for breeding of Eisenia fetida with different
ranges of animal and vegetable wastes under aerobic condition with a temperature
range of 15–20
C, moisture 80–90%, ammonia content <0.5 mg/g, salt content
<0.5% and pH in the range of 5–9. He found that the population density of
earthworms per unit volume or weight of waste was very important in affecting
the rate of growth and reproduction.
With an increase in temperature, the metabolism rate of the earthworm is also
increased which requires more food stock for the same. Tripathi et al. (2011) studied
the effects of varying temperatures (12–44
C) on the specific activity of cytoplasmic
malate dehydrogenase (cMDH), mitochondrial malate dehydrogenase (mMDH) and
lactate dehydrogenase (LDH) in earthworms. They concluded that the specific
activity of the above-said enzymes decreases in the earthworm with an increase in
temperature and vice versa. They also reported that this change in enzyme activity is
dependent on the ecological category of the earthworm species. They observed more
variations in the enzyme activity in earthworm with epigeic ecological nature while
less variation was observed in the endogeic ecological nature of earthworm species.
The less variation in endogeic earthworm species was due to less temperature
fluctuation within the soil.
The abundance of earthworms is very less during the winter periods which acts as
a harsh condition for earthworm survival. According to Robinson et al. (2018), there
was a decrease in the mean weight and growth in the invertebrate soil fauna with a
change in soil temperature, but the impacts of temperature on the invertebrate
population varied from species to species. Kanianska et al. (2016) observed that
no earthworm species have been reported from the sites having high soil temperature
and low precipitation. Thus, appropriate soil temperature is a limiting factor for
earthworm survival in the soil. Haokip and Singh (2012) observed that earthworm
abundance and diversity should be at a maximum level when the threshold level of
342
S. Singh et al.