T. festivae, Gryon monspeliensis and Ooencyrtus telenomicida) also parasitized sunn
pest eggs. T. grandis emerges prior to the remnant species, but often leaves wheat
field late spring and before harvesting. Except for T. grandis, the other species had
no determined trend and some were rare (Such as T. festivae and particularly
G. monspelinsis). T. basalis, T. rufiventris and O. telenomicida often were seen
late spring and predominated in number when T. grandis left the cereal fields toward
other crops, adjacent orchards, and shade trees at June. Harsh condition of June (dry
and warm) lead T. grandis to leave cereal fields and inferior species become
prevalent. The majority of these species also trapped in other field crops later.
Three species also were added in orchards and shade trees including T. delucchii,
T. radjabii and Anastatus bifasciatus Forcroy (Hym.: Eupelmidae). The latter
species included only males. Although, these species can successfully develop
within sunn pest eggs, they never have seen in cereal fields. Their target hosts are
other bugs and moths (Iranipour et al. 1998b).
The richness of parasitoids in East Azarbaijan province is poorer. In this province,
just five species collected in fields; T. grandis is prevalent again, followed by
T. djadetshkoe, with late emergence of O. telenomicida and O. fecundus.
T. vassilievi also is an occasional parasitoid (Nozad-Bonab and Iranipour 2010).
In Golestan province during spring, T. grandis (60%) followed by T. simoni
(40%) was observed by sweeping in a single sampling date (Iranipour et al. 1998a).
This record is important because T. simoni seems has a very restricted distribution in
Iran (northern province of Golestan with relatively high precipitation and relative
humidity). The previous record from Varamin with a hot and dry climate (Shojai
1989) is not confirmed by a subsequent study in a four-year interval (Iranipour et al.
2011). The mentioned record may be related to a relative species, T. festive with an
elegant difference in scutellar sculptures. This species is a specific parasitoid of
Eurydema spp. and seldom attack sunn pest eggs and two records of it are present in
other parts of Tehran province and adjacent Alborz province (Radjabi 1994;
Iranipour 1996). Another important record is T. agriopae by Mehravar et al.
(2000). This was the first record of a species from oobius group of Kozlov and
Kononova (1983) in Iran. One probable explanation for observed difference among
different regions is thermal requirements of different species (see Sect. 8.5.1.3).
8.3.2 How Competing Parasitoids Co-exist?
Different thermal requirements may be also a possible mechanism of co-existence
and avoiding competitive displacement, although other separation mechanisms such
as host range, density dependence, etc. also can be involved. Shafaei et al. (2011)
showed that T. grandis and T. djadetshkoe are only species that continuously present
in West Azarbaijan fields during the growing season. Three overlapping generations
of the former embedded two mainly separate generations of the latter. Peaks of the
T. djadetshkoe population coincides T. grandis declines. Thus, T. djadetshkoe
appears later and terminates its activity sooner or simultaneously and therefore
8 Superfamily Platygastroidea: Natural Enemies of True Bugs, Moths, Other. . .
309
pest eggs. T. grandis emerges prior to the remnant species, but often leaves wheat
field late spring and before harvesting. Except for T. grandis, the other species had
no determined trend and some were rare (Such as T. festivae and particularly
G. monspelinsis). T. basalis, T. rufiventris and O. telenomicida often were seen
late spring and predominated in number when T. grandis left the cereal fields toward
other crops, adjacent orchards, and shade trees at June. Harsh condition of June (dry
and warm) lead T. grandis to leave cereal fields and inferior species become
prevalent. The majority of these species also trapped in other field crops later.
Three species also were added in orchards and shade trees including T. delucchii,
T. radjabii and Anastatus bifasciatus Forcroy (Hym.: Eupelmidae). The latter
species included only males. Although, these species can successfully develop
within sunn pest eggs, they never have seen in cereal fields. Their target hosts are
other bugs and moths (Iranipour et al. 1998b).
The richness of parasitoids in East Azarbaijan province is poorer. In this province,
just five species collected in fields; T. grandis is prevalent again, followed by
T. djadetshkoe, with late emergence of O. telenomicida and O. fecundus.
T. vassilievi also is an occasional parasitoid (Nozad-Bonab and Iranipour 2010).
In Golestan province during spring, T. grandis (60%) followed by T. simoni
(40%) was observed by sweeping in a single sampling date (Iranipour et al. 1998a).
This record is important because T. simoni seems has a very restricted distribution in
Iran (northern province of Golestan with relatively high precipitation and relative
humidity). The previous record from Varamin with a hot and dry climate (Shojai
1989) is not confirmed by a subsequent study in a four-year interval (Iranipour et al.
2011). The mentioned record may be related to a relative species, T. festive with an
elegant difference in scutellar sculptures. This species is a specific parasitoid of
Eurydema spp. and seldom attack sunn pest eggs and two records of it are present in
other parts of Tehran province and adjacent Alborz province (Radjabi 1994;
Iranipour 1996). Another important record is T. agriopae by Mehravar et al.
(2000). This was the first record of a species from oobius group of Kozlov and
Kononova (1983) in Iran. One probable explanation for observed difference among
different regions is thermal requirements of different species (see Sect. 8.5.1.3).
8.3.2 How Competing Parasitoids Co-exist?
Different thermal requirements may be also a possible mechanism of co-existence
and avoiding competitive displacement, although other separation mechanisms such
as host range, density dependence, etc. also can be involved. Shafaei et al. (2011)
showed that T. grandis and T. djadetshkoe are only species that continuously present
in West Azarbaijan fields during the growing season. Three overlapping generations
of the former embedded two mainly separate generations of the latter. Peaks of the
T. djadetshkoe population coincides T. grandis declines. Thus, T. djadetshkoe
appears later and terminates its activity sooner or simultaneously and therefore
8 Superfamily Platygastroidea: Natural Enemies of True Bugs, Moths, Other. . .
309