significant positive relationship between wheat resistance to Russian wheat aphid
and effect on developmental time, fecundity, survival and predation rate of
H. variegata. Suppose this synergistic effect is shown to be occurred and confirmed
by more real field experiments, in that case, there is a big step towards combining
biological control and host plant resistance against Russian wheat aphid. Correspondingly, the effect of four host plants of English grain aphid, S. avenae on life
table parameters of H .variegata has been assessed (Ghafouri Moghaddam et al.
2016). They suggested that the wheat (c.v. Tajan) was the most suitable among four
host plants tested while the barley (c.v. dasht) was the least suitable for H. variegata
as a host plant of S. avenae. This difference could be chemical-based; indeed
semiochemicals of different host plants or even different cultivars might affect
growth, development and reproduction of lady beetles indirectly.
One of the major applications of life table is the mass rearing of predator and
parasitoids. Mass rearing of lady beetles, especially H. variegata have been noted in
many Iranian kinds of literature. Most of those studies have been carried out by using
natural aphid species as prey. Talebi et al. (2014) tested the basic biology of
H. variegata on three cereal species and in terms of female body weights, the
S. avenae was the most profitable species to feed. As a rare study, it has been
shown that the use of canola pollen with black bean aphid significantly reduced the
larval period and improved the rearing of H. variegata (Mirkhalilzadeh Ershadi et al.
2013). Besides, they tested the effect of different artificial diets on survival and
fecundity of H. variegata and concluded that it completed life cycle on some
artificial diet albeit with a lower rate (Mirkhalilzadeh Ershadi et al. 2013). However,
they did not assess the effect of feeding from artificial diets on fecundity of
H. variegata. It seems that there is still a big gap between suitability of natural
prey species and artificial diets in terms of Hippodmia fecundity. As a novel
case study, Davoodi Dehkordi et al. (2013) proved that with increasing prey
densities, the fecundity and intrinsic rate of increase of H. variegata raised while
the developmental time and preoviposition period decreased. This study stressed the
role of prey biomass quantity that a lady beetle receives to reach the development
and reproduction potentials. Optimization of lady beetle sex ratio in mass rearing
project is an ignored aspect which was addressed (Aldaghi et al. 2013). They showed
that despite common belief, the fecundity of H. variegata is not reduced with
decreasing male to female ratio; therefore they recommended sex ratio could be
manipulated in laboratory rearings of variegated lady beetle in such a way that saves
labor and maximizes reproduction output.
Demographic toxicology studies have been started recently in Iran. Some
researchers studied the effects of different pesticides and acute or sublethal effects
of many compounds with different modes of action assessed on life history and
reproduction of different lady beetles especially Hippodamia variegata (Table 2.1).
Possible use of H. variegata with pesticide application surveyed by evaluating the
sublethal effect of pesticides on life history and demography of lady beetles.
(Alimohammadi Davarani et al. 2013; Rahmani and Bandani 2013b). For instance,
the safety of Spirodiclofen to larval stages of H. variegata was revealed; however, it
was not safe for eggs (Alimohammadi Davarani et al. 2014). This information
48
H. Madadi
and effect on developmental time, fecundity, survival and predation rate of
H. variegata. Suppose this synergistic effect is shown to be occurred and confirmed
by more real field experiments, in that case, there is a big step towards combining
biological control and host plant resistance against Russian wheat aphid. Correspondingly, the effect of four host plants of English grain aphid, S. avenae on life
table parameters of H .variegata has been assessed (Ghafouri Moghaddam et al.
2016). They suggested that the wheat (c.v. Tajan) was the most suitable among four
host plants tested while the barley (c.v. dasht) was the least suitable for H. variegata
as a host plant of S. avenae. This difference could be chemical-based; indeed
semiochemicals of different host plants or even different cultivars might affect
growth, development and reproduction of lady beetles indirectly.
One of the major applications of life table is the mass rearing of predator and
parasitoids. Mass rearing of lady beetles, especially H. variegata have been noted in
many Iranian kinds of literature. Most of those studies have been carried out by using
natural aphid species as prey. Talebi et al. (2014) tested the basic biology of
H. variegata on three cereal species and in terms of female body weights, the
S. avenae was the most profitable species to feed. As a rare study, it has been
shown that the use of canola pollen with black bean aphid significantly reduced the
larval period and improved the rearing of H. variegata (Mirkhalilzadeh Ershadi et al.
2013). Besides, they tested the effect of different artificial diets on survival and
fecundity of H. variegata and concluded that it completed life cycle on some
artificial diet albeit with a lower rate (Mirkhalilzadeh Ershadi et al. 2013). However,
they did not assess the effect of feeding from artificial diets on fecundity of
H. variegata. It seems that there is still a big gap between suitability of natural
prey species and artificial diets in terms of Hippodmia fecundity. As a novel
case study, Davoodi Dehkordi et al. (2013) proved that with increasing prey
densities, the fecundity and intrinsic rate of increase of H. variegata raised while
the developmental time and preoviposition period decreased. This study stressed the
role of prey biomass quantity that a lady beetle receives to reach the development
and reproduction potentials. Optimization of lady beetle sex ratio in mass rearing
project is an ignored aspect which was addressed (Aldaghi et al. 2013). They showed
that despite common belief, the fecundity of H. variegata is not reduced with
decreasing male to female ratio; therefore they recommended sex ratio could be
manipulated in laboratory rearings of variegated lady beetle in such a way that saves
labor and maximizes reproduction output.
Demographic toxicology studies have been started recently in Iran. Some
researchers studied the effects of different pesticides and acute or sublethal effects
of many compounds with different modes of action assessed on life history and
reproduction of different lady beetles especially Hippodamia variegata (Table 2.1).
Possible use of H. variegata with pesticide application surveyed by evaluating the
sublethal effect of pesticides on life history and demography of lady beetles.
(Alimohammadi Davarani et al. 2013; Rahmani and Bandani 2013b). For instance,
the safety of Spirodiclofen to larval stages of H. variegata was revealed; however, it
was not safe for eggs (Alimohammadi Davarani et al. 2014). This information
48
H. Madadi