N. californicus (intraguild prey). They showed that type of prey before adulthood in
P. persimilis did not have an effect on the level of its aggressiveness on spider mites
eggs. Also, in another study, the effect of starvation on aggressiveness against spider
mites and conspecific in N. californicus was studied and declared starved predators
attacked T. urticae after 30 Æ 0 min whereas satiated predators attacked only after
68 Æ 8 min. Also, attack on conspecific larvae was shorter in starved than satiated
predators (Borji et al. 2011).
Cannibalism
Cannibalism is defined as the consumption of conspecific individuals that was seen
in the animal kingdom (Schausberger 2003). In the case of prey scarcity, this
phenomenon can assist in conservation of predator population and has been shown
to occur in phytoseiidae (Schausberger and Croft 2000; Walzer et al. 2001;
Schausberger 2003; Zannou et al. 2005). The specialist predators act less as cannibal
in comparison with generalist predator (Walzer and Schausberger 1999b; Farazmand
et al. 2014; Ghasemloo et al. 2016). Schausberger and Croft (2000) demonstrated that
cannibalistic individuals have the ability to discriminate between kin and non-kin
and reported the specialist phytoseiids P. persimilis and P. macropilis are able to
discriminate between related and unrelated larvae and preferentially consumed
unrelated larvae when given a choice. Also, the effect of kinship on the mating
preference of P. persimilis by Dehghani Tafti et al. (2013) was studied and described
P. persimilis was not able to discriminate between kin and non-kin males. In another
study, the effect of kinship on oviposition patterns of P. persimilis was discussed and
showed that kinship decreased the distance between first and second eggs (Zeraatkar
et al. 2013).
3.2.1.4.8 Mass Rearing
Mass rearing and releasing predatory mites, mostly phytoseiids, are one of the goals
of biological control programs (McMurtry and Croft 1997). Methods for mass
rearing of phytoseiids were proposed by McMurtry and Scriven (1971) and Gerson
et al. (2003). Specialist phytoseiids require spider mites for efficient mass-rearing
(McMurtry et al. 2015) and it is necessary to have a pure spider mite culture
(Morales-Ramos and Rojas 2014), while pollen and honeydew produced by greenhouse whitefly can keep the generalist predators population in the absence of their
pests (Mortazavi et al. 2018). Recently, Nguyen et al. (2015) studied population
growth of four phytoseiids (N. californicus, N. cucumeris, A. andersoni and
A. limonicus) on natural and artificial diets and showed growth rate was lower on
artificial diet than on natural food, but survival was similar. These artificial diets may
be useful as food supplements to protect predator populations after release in the
crop (Wade et al. 2008). One of the cheap and effective sources for rearing some
phytoseiids is pollen (McMurtry et al. 2015). Shirdel et al. (2002) compared rearing
of Typhlodromus kettanehi Dosse and Euseius finlandicus (Oudemans) on two types
of arenas (plastic or bean leaf) and three diets (T. urticae, almond pollen + T. urticae
104
H. Hajiqanbar and A. Farazmand
P. persimilis did not have an effect on the level of its aggressiveness on spider mites
eggs. Also, in another study, the effect of starvation on aggressiveness against spider
mites and conspecific in N. californicus was studied and declared starved predators
attacked T. urticae after 30 Æ 0 min whereas satiated predators attacked only after
68 Æ 8 min. Also, attack on conspecific larvae was shorter in starved than satiated
predators (Borji et al. 2011).
Cannibalism
Cannibalism is defined as the consumption of conspecific individuals that was seen
in the animal kingdom (Schausberger 2003). In the case of prey scarcity, this
phenomenon can assist in conservation of predator population and has been shown
to occur in phytoseiidae (Schausberger and Croft 2000; Walzer et al. 2001;
Schausberger 2003; Zannou et al. 2005). The specialist predators act less as cannibal
in comparison with generalist predator (Walzer and Schausberger 1999b; Farazmand
et al. 2014; Ghasemloo et al. 2016). Schausberger and Croft (2000) demonstrated that
cannibalistic individuals have the ability to discriminate between kin and non-kin
and reported the specialist phytoseiids P. persimilis and P. macropilis are able to
discriminate between related and unrelated larvae and preferentially consumed
unrelated larvae when given a choice. Also, the effect of kinship on the mating
preference of P. persimilis by Dehghani Tafti et al. (2013) was studied and described
P. persimilis was not able to discriminate between kin and non-kin males. In another
study, the effect of kinship on oviposition patterns of P. persimilis was discussed and
showed that kinship decreased the distance between first and second eggs (Zeraatkar
et al. 2013).
3.2.1.4.8 Mass Rearing
Mass rearing and releasing predatory mites, mostly phytoseiids, are one of the goals
of biological control programs (McMurtry and Croft 1997). Methods for mass
rearing of phytoseiids were proposed by McMurtry and Scriven (1971) and Gerson
et al. (2003). Specialist phytoseiids require spider mites for efficient mass-rearing
(McMurtry et al. 2015) and it is necessary to have a pure spider mite culture
(Morales-Ramos and Rojas 2014), while pollen and honeydew produced by greenhouse whitefly can keep the generalist predators population in the absence of their
pests (Mortazavi et al. 2018). Recently, Nguyen et al. (2015) studied population
growth of four phytoseiids (N. californicus, N. cucumeris, A. andersoni and
A. limonicus) on natural and artificial diets and showed growth rate was lower on
artificial diet than on natural food, but survival was similar. These artificial diets may
be useful as food supplements to protect predator populations after release in the
crop (Wade et al. 2008). One of the cheap and effective sources for rearing some
phytoseiids is pollen (McMurtry et al. 2015). Shirdel et al. (2002) compared rearing
of Typhlodromus kettanehi Dosse and Euseius finlandicus (Oudemans) on two types
of arenas (plastic or bean leaf) and three diets (T. urticae, almond pollen + T. urticae
104
H. Hajiqanbar and A. Farazmand