(Cresson) (Vinson and Scarborough 1991). Many aphid species are recorded as
attended by ants, which are also parasitized by Lysiphlebus fabarum in Iran
(Rakhshani et al. 2013).
9.4 Aphid Parasitoids in Various Ecosystems
9.4.1 Aphid Parasitoids in Farmlands and Orchards, Host
Range and Economic Importance
The best model of aphid parasitoid association with economic importance can be
found in the farmlands and fruit orchards as the main source of food production for
the human society. The agro-ecosystem is generally referring to a simplified ecosystem, in which the core lies on the agricultural activity by human. It is not an
appropriate situation to open the big problems occurred in the ecosystems by these
modifications, but an escape to the changes in natural aphid-parasitoid association
would be useful enough. Cereals are the main crop that has occupied the vast
majority of the agricultural fields. There are many other field crops, which more or
less suffering from the aphid infestation, but no concern was paid on the cereal
aphids in Iran, comparing other parts of the world, especially in Europe and North
America. A series of researches arbitrarily targeted the aphid parasitoids in farmlands and fruit orchards, but a valuable amount of data from the surrounding areas
were also compiled (Rakhshani et al. 2012b; Nazari et al. 2012; Alikhani et al. 2013;
Barahoei et al. 2013). A moderately common and well known aphids are associated
with cereals throughout the world, with some relevant differences on their biology
and economic importance (Dixon 1987). They may occur irregularly in various
regions or with some gradient patterns (Rakhshani et al. 2008b). Depending on the
host plants, different aphids may be more frequent than others, i.e. Rhopalosiphum
maidis (Fitch) is rather common in corn fields comparing other aphids. Ignoring the
host plant associations, an efficient group of aphid parasitoids can be found in cereal
fields, each of them have its own preference, when encountering various host aphids.
The rare and non-economic Sipha aphids are associated with Adialytus ambiguus
(Haliday), which has no other host aphid in such environment, was occurred. Other
aphids including Diuraphis noxia (Mordvilko), Sitobion avenae (Fabricius),
Schizaphis graminum (Rondani), Metopolophium dirhodum (Walker),
Rhopalosiphum padi (L.) and Rhopalosiphum maidis (Fitch), all can be parasitized
by Praon volucre (Haliday). The cabbage aphid parasitoid, Diaeretiella rapae
(M’Intosh) has a significant affinity to Diuraphis noxia (Mordvilko) (Rakhshani
et al. 2008b), but the records (Pike et al. 1999; Singh and Singh 2015) indicating it
does not have limit for the host association at least in the cereal fields. At the same
way, Aphidius uzbekistanicus Luzhetzki is mainly in association with Sitobion
avenae (Rakhshani et al. 2008a), the preferred host for Aphidius ervi Haliday,
which is not so common in cereal fields in Iran.
9 Aphid Parasitoids: Aphidiinae (Hym., Braconidae)
353
attended by ants, which are also parasitized by Lysiphlebus fabarum in Iran
(Rakhshani et al. 2013).
9.4 Aphid Parasitoids in Various Ecosystems
9.4.1 Aphid Parasitoids in Farmlands and Orchards, Host
Range and Economic Importance
The best model of aphid parasitoid association with economic importance can be
found in the farmlands and fruit orchards as the main source of food production for
the human society. The agro-ecosystem is generally referring to a simplified ecosystem, in which the core lies on the agricultural activity by human. It is not an
appropriate situation to open the big problems occurred in the ecosystems by these
modifications, but an escape to the changes in natural aphid-parasitoid association
would be useful enough. Cereals are the main crop that has occupied the vast
majority of the agricultural fields. There are many other field crops, which more or
less suffering from the aphid infestation, but no concern was paid on the cereal
aphids in Iran, comparing other parts of the world, especially in Europe and North
America. A series of researches arbitrarily targeted the aphid parasitoids in farmlands and fruit orchards, but a valuable amount of data from the surrounding areas
were also compiled (Rakhshani et al. 2012b; Nazari et al. 2012; Alikhani et al. 2013;
Barahoei et al. 2013). A moderately common and well known aphids are associated
with cereals throughout the world, with some relevant differences on their biology
and economic importance (Dixon 1987). They may occur irregularly in various
regions or with some gradient patterns (Rakhshani et al. 2008b). Depending on the
host plants, different aphids may be more frequent than others, i.e. Rhopalosiphum
maidis (Fitch) is rather common in corn fields comparing other aphids. Ignoring the
host plant associations, an efficient group of aphid parasitoids can be found in cereal
fields, each of them have its own preference, when encountering various host aphids.
The rare and non-economic Sipha aphids are associated with Adialytus ambiguus
(Haliday), which has no other host aphid in such environment, was occurred. Other
aphids including Diuraphis noxia (Mordvilko), Sitobion avenae (Fabricius),
Schizaphis graminum (Rondani), Metopolophium dirhodum (Walker),
Rhopalosiphum padi (L.) and Rhopalosiphum maidis (Fitch), all can be parasitized
by Praon volucre (Haliday). The cabbage aphid parasitoid, Diaeretiella rapae
(M’Intosh) has a significant affinity to Diuraphis noxia (Mordvilko) (Rakhshani
et al. 2008b), but the records (Pike et al. 1999; Singh and Singh 2015) indicating it
does not have limit for the host association at least in the cereal fields. At the same
way, Aphidius uzbekistanicus Luzhetzki is mainly in association with Sitobion
avenae (Rakhshani et al. 2008a), the preferred host for Aphidius ervi Haliday,
which is not so common in cereal fields in Iran.
9 Aphid Parasitoids: Aphidiinae (Hym., Braconidae)
353