is doubtlessly also definable by the number of finding prey availability, hence more
diversified communities may also increase the role of refugium for target parasitoids.
Another aspect of a refugium is dealing with the aphids migrating to their
secondary host plant in late season. The parasitized alate aphids may also transfer
the parasitoids into the colonies in the refugium, where they can multiply for the rest
of season. Hyalopterus aphids are good example, which migrates from the weeds
(Phragmites) to plums, peaches, apricots, where it is a pest. The parasitoid,
A. transcaspicus is associated with the aphid in both these systems. So, it is not far
expected to find this parasitoid in the wetlands, where it can attack the secondary
host aphid, Melanaphis donacis (Passerini) on Arundo donax (Tomanović et al.
2012). Inter-cropping is a new agro-technical approach, which believe to increase
the diversity and population of the natural enemies and should be considered in
insect pest management programs. The alternative host plant for both pest aphid and
its parasitoids known as “reservoir” can be provided both within and outside of the
field. Preservation of the naturally growing plants (not the persistent weeds) provide
shelter and food source for the aphid parasitoids during and after the growing season.
The parasitoids can also multiply their populations on the innocuous aphid species
living on the surrounding plants (Starý 1972b; Tylianakis et al. 2004). According to
the database of the host records, it is possible to select the alternative host plants,
which can act as the best reservoirs at each agro-ecosystem. Such reservoirs of the
beneficial aphid parasitoids are investigated by various authors (Perrin 1975; Starý
1982, 1983, 1986a, b; Kavallieratos et al. 2002, 2008; Havelka et al. 2012).
9.6.2 Importance of Conservation Programs
Aphid parasitoids play an important role in natural control of the aphid population in
various habitats (Starý 1970a, b). Fauna of Iran includes a number of endemic plants
and associated food webs composed also from aphids and their parasitoids. Primarily, such food webs are associated with plants and, therefore, all the conservation
programmes targeting the plants simultaneously conserve the associated webs of
aphids and parasitoids. This concerns namely the important, often endemic, but
possibly less known natural ecosystems of Iran, from the mountains to the semideserts (Barahoei et al. 2013; Nazari et al. 2012; Alikhani et al. 2013; Taheri and
Rakhshani 2013). These evidences are important in the cases, where the aphid
species have their native home and are in association with their native parasitoids.
Conservation is one of the major aspect of biological control strategies that has
received the least attention, at least in the case of aphid parasitoids. It has been
defined as increase the effectiveness of natural enemies through manipulation of the
environment and agricultural landscapes, which led to enhancing the longevity,
fecundity and survival rate of the natural enemies (Cortesero et al. 2000; Landis
et al. 2000). Many farming practices can be categorized as conservation methods,
even those can relieve the unfavourable factors. Providing the supplementary food
resources, shelters and refugium within or outside the arable crop are the most
374
E. Rakhshani and P. Starý
diversified communities may also increase the role of refugium for target parasitoids.
Another aspect of a refugium is dealing with the aphids migrating to their
secondary host plant in late season. The parasitized alate aphids may also transfer
the parasitoids into the colonies in the refugium, where they can multiply for the rest
of season. Hyalopterus aphids are good example, which migrates from the weeds
(Phragmites) to plums, peaches, apricots, where it is a pest. The parasitoid,
A. transcaspicus is associated with the aphid in both these systems. So, it is not far
expected to find this parasitoid in the wetlands, where it can attack the secondary
host aphid, Melanaphis donacis (Passerini) on Arundo donax (Tomanović et al.
2012). Inter-cropping is a new agro-technical approach, which believe to increase
the diversity and population of the natural enemies and should be considered in
insect pest management programs. The alternative host plant for both pest aphid and
its parasitoids known as “reservoir” can be provided both within and outside of the
field. Preservation of the naturally growing plants (not the persistent weeds) provide
shelter and food source for the aphid parasitoids during and after the growing season.
The parasitoids can also multiply their populations on the innocuous aphid species
living on the surrounding plants (Starý 1972b; Tylianakis et al. 2004). According to
the database of the host records, it is possible to select the alternative host plants,
which can act as the best reservoirs at each agro-ecosystem. Such reservoirs of the
beneficial aphid parasitoids are investigated by various authors (Perrin 1975; Starý
1982, 1983, 1986a, b; Kavallieratos et al. 2002, 2008; Havelka et al. 2012).
9.6.2 Importance of Conservation Programs
Aphid parasitoids play an important role in natural control of the aphid population in
various habitats (Starý 1970a, b). Fauna of Iran includes a number of endemic plants
and associated food webs composed also from aphids and their parasitoids. Primarily, such food webs are associated with plants and, therefore, all the conservation
programmes targeting the plants simultaneously conserve the associated webs of
aphids and parasitoids. This concerns namely the important, often endemic, but
possibly less known natural ecosystems of Iran, from the mountains to the semideserts (Barahoei et al. 2013; Nazari et al. 2012; Alikhani et al. 2013; Taheri and
Rakhshani 2013). These evidences are important in the cases, where the aphid
species have their native home and are in association with their native parasitoids.
Conservation is one of the major aspect of biological control strategies that has
received the least attention, at least in the case of aphid parasitoids. It has been
defined as increase the effectiveness of natural enemies through manipulation of the
environment and agricultural landscapes, which led to enhancing the longevity,
fecundity and survival rate of the natural enemies (Cortesero et al. 2000; Landis
et al. 2000). Many farming practices can be categorized as conservation methods,
even those can relieve the unfavourable factors. Providing the supplementary food
resources, shelters and refugium within or outside the arable crop are the most
374
E. Rakhshani and P. Starý