as biocontrol agents (De clercq et al. 2000; Reis et al. 2003; Badii et al. 2004; Xiao
and Fadamiro 2010).
The functional response of phytoseiids is influenced by a number of factors such as
temperature (Gotoh et al. 2004; Kouhjani Gorji et al. 2009; Jafari et al. 2012), host
plant (Cédola et al. 2001; Ahn et al. 2010), insecticides (Poletti et al. 2007), prey
stage (Farazmand et al. 2012) and age of predator (Fathipour et al. 2017, 2018).
Functional response can explain search efficiencies and predation rates of predators
and the evaluation of this behaviour of predators is a critical first step in determining
their ability to regulate the prey (Ahn et al. 2010; Xiao and Fadamiro 2010). Native
and exotic phytoseiids show type II functional response. Functional response parameters of some native and introduced phytoseiid mites are given in Table 3.1.
One of the most important aspects of interactions among multiple conspecific
predators is known as direct mutual interference. Hassell and Varley (1969) and
Hassell and May (1974) described the importance of this phenomenon. This behaviour results in a reduction in searching efficiency because of time wasted when
conspecifics encounter each other rather than handling (capturing) prey (Henne and
Johnson 2010). However, mutual interference can assist mass rearing of predatory
mites in laboratory conditions and also simplify the explanation of observed outcomes in the field. This phenomenon has been studied in native phytoseiid mite,
Typhlodromus bagdasarjani and P. plumifer (Farazmand et al. 2012; Khodayari
et al. 2016) and an introduced mite Neoseiulus californicus (Farazmand et al. 2012).
In a survey, the effect of prey (spider mite) density on developmental time of
P. persimilis and N. californicus was investigated and demonstrated that increasing
the prey density did not effect on the development period of P. persimilis but there
was significant difference for N. californicus (Nadeali et al. 2012a, b). Also, Zahedi
et al. (2012) investigated the effect of prey density on oviposition rate of
P. persimilis and stated that there is a direct relation between prey density and
oviposition rate.
Prey Stage Preference
Prey stage preference may influence prey-predator population dynamics if the prey
stage affects the development and reproduction of the predator (Pandey and Singh
1999). Understanding the prey-stage preferences of a biological control agent is
necessary for the success of biological control programs as it assists with mass
rearing efforts and can facilitate prey-predator population dynamics in the field
(Pasandideh et al. 2015). Xiao and Fadamiro (2010) showed P. persimilis,
G. occidentalis and N. californicus preferred nymphs to eggs of Panonychus citri
(McGregor). Blackwood et al. (2001) stated adult females of P. persimilis preferred
eggs of T. urticae over the larvae, while G. occidentalis and N. californicus showed
no prey-stage preference. In another study, Badii et al. (2004) indicated that Euseius
hibisci (Chant) consumed significantly more prey eggs than other prey stages. In
contrast, Xiao et al. (2013) reported that N. californicus and A. swirskii equally
preferred to feed on both eggs and nymphs of T. urticae.
3 Biological Control of Pests by Mites in Iran
95
and Fadamiro 2010).
The functional response of phytoseiids is influenced by a number of factors such as
temperature (Gotoh et al. 2004; Kouhjani Gorji et al. 2009; Jafari et al. 2012), host
plant (Cédola et al. 2001; Ahn et al. 2010), insecticides (Poletti et al. 2007), prey
stage (Farazmand et al. 2012) and age of predator (Fathipour et al. 2017, 2018).
Functional response can explain search efficiencies and predation rates of predators
and the evaluation of this behaviour of predators is a critical first step in determining
their ability to regulate the prey (Ahn et al. 2010; Xiao and Fadamiro 2010). Native
and exotic phytoseiids show type II functional response. Functional response parameters of some native and introduced phytoseiid mites are given in Table 3.1.
One of the most important aspects of interactions among multiple conspecific
predators is known as direct mutual interference. Hassell and Varley (1969) and
Hassell and May (1974) described the importance of this phenomenon. This behaviour results in a reduction in searching efficiency because of time wasted when
conspecifics encounter each other rather than handling (capturing) prey (Henne and
Johnson 2010). However, mutual interference can assist mass rearing of predatory
mites in laboratory conditions and also simplify the explanation of observed outcomes in the field. This phenomenon has been studied in native phytoseiid mite,
Typhlodromus bagdasarjani and P. plumifer (Farazmand et al. 2012; Khodayari
et al. 2016) and an introduced mite Neoseiulus californicus (Farazmand et al. 2012).
In a survey, the effect of prey (spider mite) density on developmental time of
P. persimilis and N. californicus was investigated and demonstrated that increasing
the prey density did not effect on the development period of P. persimilis but there
was significant difference for N. californicus (Nadeali et al. 2012a, b). Also, Zahedi
et al. (2012) investigated the effect of prey density on oviposition rate of
P. persimilis and stated that there is a direct relation between prey density and
oviposition rate.
Prey Stage Preference
Prey stage preference may influence prey-predator population dynamics if the prey
stage affects the development and reproduction of the predator (Pandey and Singh
1999). Understanding the prey-stage preferences of a biological control agent is
necessary for the success of biological control programs as it assists with mass
rearing efforts and can facilitate prey-predator population dynamics in the field
(Pasandideh et al. 2015). Xiao and Fadamiro (2010) showed P. persimilis,
G. occidentalis and N. californicus preferred nymphs to eggs of Panonychus citri
(McGregor). Blackwood et al. (2001) stated adult females of P. persimilis preferred
eggs of T. urticae over the larvae, while G. occidentalis and N. californicus showed
no prey-stage preference. In another study, Badii et al. (2004) indicated that Euseius
hibisci (Chant) consumed significantly more prey eggs than other prey stages. In
contrast, Xiao et al. (2013) reported that N. californicus and A. swirskii equally
preferred to feed on both eggs and nymphs of T. urticae.
3 Biological Control of Pests by Mites in Iran
95