Diaeretiella rapae throughout 87 countries (Singh and Singh 2015). The cabbage
aphid, Brevicoryne brassicae (L.) as its preferred and frequently encountered host
aphid is considered as ancestral association for Diaeretiella rapae (Némec and Starý
1994; Pike et al. 1999). This aphid has no other parasitoid, indeed and other records
seem to be the result of the observations on the mixed colonies (especially with
Myzus persicae). Diaeretiella rapae has also a strong affinity to the Russian wheat
aphid, Diuraphis noxia (Mordvilko) in cereal fields (Rakhshani et al. 2008b). It is yet
unclear how this parasitoid species is able to overcome the host range barriers, while
the genetic differences bearing not enough insights and correlations with its diversification and host range pattern (Baer et al. 2004).
9.3 Biology of Aphid Parasitoids
The followed fundamental research approach requires basically a good level of
identification of all the food-web participants. A useful respective identification
co-work net has to be organized as a background interacting with the database
development. Many studies are contributed to various aspects of ecology and
biology of the important aphid parasitoids including their seasonal occurrence
(Monajemi and Esmaili 1981; Rakhshani et al. 2000, 2004b, 2009; Ghotbi Ravandi
et al. 2017), life history and demography (Talebi et al. 2002, Tahriri et al. 2010;
Tazerouni et al. 2012a, b, 2013; Zamani et al. 2007, 2012; Pourtaghi et al. 2016;
Ameri et al. 2015), functional response and foraging behavior (Takalloozadeh et al.
2004b; Fathipour et al. 2006; Zamani et al. 2006; Tahriri et al. 2007; Rasekh et al.
2010a, b, c, d; Bazyar et al. 2012; Farhad et al. 2011; Tazerouni et al. 2011, 2012c,
2016, 2017; Ameri et al. 2013; Pasandideh et al. 2015) and host preference
(Rakhshani et al. 2004a; Takalloozadeh et al. 2004a; Talebi et al. 2006; Tahriri
et al. 2007; Pasandideh et al. 2015; Najafpour et al. 2016). These surveys are
generally focused on the economically important aphids and their parasitoids in
laboratory conditions, and in the field to a lesser extent. There are yet many
important aphid parasitoids for which almost no biological data are available.
Valuable data were achieved on the basis of laboratory experiments that should be
expanded in the natural conditions, too.
9.3.1 Seasonal Occurrence
Aphid communities are characterized by their complicated trophic interactions and
the associated natural enemies, among them the parasitoids have usually more
dependence and adaptations to the host population. There is a moderately wide
spectrum of the aphid parasitoids in the field crops, represented by the wheat
(Rakhshani et al. 2008b) and alfalfa (Rakhshani et al. 2006a). Very few studies on
the population dynamics and seasonal occurrence of the aphid parasitoids were
9 Aphid Parasitoids: Aphidiinae (Hym., Braconidae)
343
aphid, Brevicoryne brassicae (L.) as its preferred and frequently encountered host
aphid is considered as ancestral association for Diaeretiella rapae (Némec and Starý
1994; Pike et al. 1999). This aphid has no other parasitoid, indeed and other records
seem to be the result of the observations on the mixed colonies (especially with
Myzus persicae). Diaeretiella rapae has also a strong affinity to the Russian wheat
aphid, Diuraphis noxia (Mordvilko) in cereal fields (Rakhshani et al. 2008b). It is yet
unclear how this parasitoid species is able to overcome the host range barriers, while
the genetic differences bearing not enough insights and correlations with its diversification and host range pattern (Baer et al. 2004).
9.3 Biology of Aphid Parasitoids
The followed fundamental research approach requires basically a good level of
identification of all the food-web participants. A useful respective identification
co-work net has to be organized as a background interacting with the database
development. Many studies are contributed to various aspects of ecology and
biology of the important aphid parasitoids including their seasonal occurrence
(Monajemi and Esmaili 1981; Rakhshani et al. 2000, 2004b, 2009; Ghotbi Ravandi
et al. 2017), life history and demography (Talebi et al. 2002, Tahriri et al. 2010;
Tazerouni et al. 2012a, b, 2013; Zamani et al. 2007, 2012; Pourtaghi et al. 2016;
Ameri et al. 2015), functional response and foraging behavior (Takalloozadeh et al.
2004b; Fathipour et al. 2006; Zamani et al. 2006; Tahriri et al. 2007; Rasekh et al.
2010a, b, c, d; Bazyar et al. 2012; Farhad et al. 2011; Tazerouni et al. 2011, 2012c,
2016, 2017; Ameri et al. 2013; Pasandideh et al. 2015) and host preference
(Rakhshani et al. 2004a; Takalloozadeh et al. 2004a; Talebi et al. 2006; Tahriri
et al. 2007; Pasandideh et al. 2015; Najafpour et al. 2016). These surveys are
generally focused on the economically important aphids and their parasitoids in
laboratory conditions, and in the field to a lesser extent. There are yet many
important aphid parasitoids for which almost no biological data are available.
Valuable data were achieved on the basis of laboratory experiments that should be
expanded in the natural conditions, too.
9.3.1 Seasonal Occurrence
Aphid communities are characterized by their complicated trophic interactions and
the associated natural enemies, among them the parasitoids have usually more
dependence and adaptations to the host population. There is a moderately wide
spectrum of the aphid parasitoids in the field crops, represented by the wheat
(Rakhshani et al. 2008b) and alfalfa (Rakhshani et al. 2006a). Very few studies on
the population dynamics and seasonal occurrence of the aphid parasitoids were
9 Aphid Parasitoids: Aphidiinae (Hym., Braconidae)
343