Trioxys pallidus was imported into California, where is an area with similar
climate to Iran and it became quickly established in all walnut-growing areas, and
led to a very successful biological control of the walnut aphid (van den Bosch et al.
1962, 1979). Simultaneous explorations were done for the parasitoid of the spotted
alfalfa aphid, Therioaphis trifolii in Iran and some other countries in the Middle East
(van den Bosch 1957). Among the collected parasitoids, Trioxys complanatus
showed the greatest activity during hot periods and successfully established in
California (Schlinger and Hall 1959). Further investigations indicated that Iranian
strain of Trioxys complanatus is highly tolerant to the extreme temperatures (Flint
1980). Praon exsoletum was also among the imported species from Iran to California
which was subsequently produced in very large numbers and colonized at many
localities throughout the alfalfa growing areas and successfully established (van den
Bosch 1957; van den Bosch et al. 1959).
Recently, because of unknown reasons the ability T. pallidus significantly
decreased to provide sufficient pest suppression (Hougardy and Mills 2009; Walton
et al. 2009). The evidences for hybridization of various strains of Trioxys pallidus in
California (Messing and Aliniazee 1988) has considered as potential reason of this
failure, but further investigations indicated that the “inbreeding depression” may be
contributing to the breakdown of biological control by T. pallidus (Andersen and
Mills 2016). Through the connection between the aforementioned researchers in
California (Andersen and Mills), Ilania Astorga, a specialist from Division of
Agricultural Protection and Forestal del SAG, Chile, tried for a fresh introduction
of Trioxys pallidus from Iran to the southern hemisphere, in 2013 & 2014. It was
expected that through program, the walnut producers will no longer need to make
exclusive applications of pesticides. The introduction is believed to be successful
(unpublished data). Aphidius transcaspicus Telenga is specialized parasitoid of
Hyalopterus aphids on Prunus spp. and widely distributed in central and western
Asia (Iran), as well as Mediterranean basin (Starý 1976, 1979). It has recently been
targeted for use as a biological control agent against the mealy plum aphid
Hyalopterus pruni (Geoffroy) in prune orchards in California (Latham and Mills
2010).
González et al. (1978) reviewed the geographical distribution of the imported
parasitoid to California for biological control of Acyrthosiphon aphids on alfalfa.
The area of explorations were some countries in the southeastern Europe and the
Middle East. Four species including Aphidius ervi Haliday, Aphidius smithi Sharma
& Subba Rao, Aphidius urticae Haliday and Praon barbatum Mackauer were
collected from Iran (and Afghanistan) that showed a different rate of parasitism in
the field condition. A considerable effort was also done to find the exotic parasitoids
of the Russian Wheat aphid (RWA) in Iran and some other countries (González et al.
1990, 1992). The most recent activity is introduction of Pauesia antennata (Mukerji)
for the biological control of the giant brown peach aphid, Pterochloroides persicae
(Cholodkovsky) from Iran to Tunisia (Mdellel et al. 2015), that is yet in evaluation
process.
It should be emphasized that search for potentially useful aphid parasitoid species
has reflected the urgent need to obtain some parasitoid targets, but often with a lack
9 Aphid Parasitoids: Aphidiinae (Hym., Braconidae)
377
climate to Iran and it became quickly established in all walnut-growing areas, and
led to a very successful biological control of the walnut aphid (van den Bosch et al.
1962, 1979). Simultaneous explorations were done for the parasitoid of the spotted
alfalfa aphid, Therioaphis trifolii in Iran and some other countries in the Middle East
(van den Bosch 1957). Among the collected parasitoids, Trioxys complanatus
showed the greatest activity during hot periods and successfully established in
California (Schlinger and Hall 1959). Further investigations indicated that Iranian
strain of Trioxys complanatus is highly tolerant to the extreme temperatures (Flint
1980). Praon exsoletum was also among the imported species from Iran to California
which was subsequently produced in very large numbers and colonized at many
localities throughout the alfalfa growing areas and successfully established (van den
Bosch 1957; van den Bosch et al. 1959).
Recently, because of unknown reasons the ability T. pallidus significantly
decreased to provide sufficient pest suppression (Hougardy and Mills 2009; Walton
et al. 2009). The evidences for hybridization of various strains of Trioxys pallidus in
California (Messing and Aliniazee 1988) has considered as potential reason of this
failure, but further investigations indicated that the “inbreeding depression” may be
contributing to the breakdown of biological control by T. pallidus (Andersen and
Mills 2016). Through the connection between the aforementioned researchers in
California (Andersen and Mills), Ilania Astorga, a specialist from Division of
Agricultural Protection and Forestal del SAG, Chile, tried for a fresh introduction
of Trioxys pallidus from Iran to the southern hemisphere, in 2013 & 2014. It was
expected that through program, the walnut producers will no longer need to make
exclusive applications of pesticides. The introduction is believed to be successful
(unpublished data). Aphidius transcaspicus Telenga is specialized parasitoid of
Hyalopterus aphids on Prunus spp. and widely distributed in central and western
Asia (Iran), as well as Mediterranean basin (Starý 1976, 1979). It has recently been
targeted for use as a biological control agent against the mealy plum aphid
Hyalopterus pruni (Geoffroy) in prune orchards in California (Latham and Mills
2010).
González et al. (1978) reviewed the geographical distribution of the imported
parasitoid to California for biological control of Acyrthosiphon aphids on alfalfa.
The area of explorations were some countries in the southeastern Europe and the
Middle East. Four species including Aphidius ervi Haliday, Aphidius smithi Sharma
& Subba Rao, Aphidius urticae Haliday and Praon barbatum Mackauer were
collected from Iran (and Afghanistan) that showed a different rate of parasitism in
the field condition. A considerable effort was also done to find the exotic parasitoids
of the Russian Wheat aphid (RWA) in Iran and some other countries (González et al.
1990, 1992). The most recent activity is introduction of Pauesia antennata (Mukerji)
for the biological control of the giant brown peach aphid, Pterochloroides persicae
(Cholodkovsky) from Iran to Tunisia (Mdellel et al. 2015), that is yet in evaluation
process.
It should be emphasized that search for potentially useful aphid parasitoid species
has reflected the urgent need to obtain some parasitoid targets, but often with a lack
9 Aphid Parasitoids: Aphidiinae (Hym., Braconidae)
377