The susceptibility of the citrus leafminer, Phyllocnistis citrella Stainton (Lep.:
Gracillariidae) to the commercial B. thuringiensis formulation (Bithiran®, Mehr
Asia Biotechnology Company, Iran) was determined under laboratory conditions
(Amiri-Besheli 2008). The studied Bt formulation demonstrated great insecticidal
activity against this pest and can be used in combination with bio-rational insecticides to increase the efficiency of leafminer management. The insecticidal activity of
certain Bt strains available in the Iranian Bt collection with lepidopteran-active genes
were assessed against the cotton bollworm, H. armigera. The toxicity of spore and
crystal mixtures of Bt strains was evaluated against the first instar larvae of
H. armigera. Two Bt strains (YD5 and KON4) were detected with great insecticidal
activity against the cotton bollworm (Seifinejad et al. 2008). Under laboratory
conditions, the insecticidal activity of spore and crystal suspensions of Iranian Bt
strains was assessed against P. brassica and C. pipiens. Some of the studied Bt
strains caused mortality higher than 75% on P. brassica and C. pipiens (Aramideh
et al. 2010). So, these Bt strains, can be considered for biological control of insect
pests. The insecticidal activity of four Iranian Bt strains isolated from soil were
assessed against P. xylostella, one the major pests of cruciferous crops, especially
cabbage fields in Tehran, and compared to that of Dipel as a commercial Bt based
insecticide (Deilamy and Abbasipour 2013). The pathogenicity of the spore and
crystal suspensions of Bt strains were investigated against third instar larvae of
P. xylostella, with Bt strain 87 found to be highly toxic for diamondback moth
(Deilamy and Abbasipour 2013).
The sub-lethal effects of B. thuringiensis subsp. kurstaki were evaluated on the
fitness and the biological parameters of H. armigera (Sedaratian et al. 2013).
Developmental time, fecundity, egg hatching percentage, net production rate (R 0 ),
intrinsic (r m ) and finite (λ) rates of increase, mean generation time (T ), mean
generation doubling time (DT) were adversely affected in the H. armigera treated
with sub-lethal concentrations of Bt. Sedaratian et al. (2013) concluded that biological performance and fitness of H. armigera were affected by exposing to the
sub-lethal concentrations of Bt.
Beyond the insect world, the biological activity of Iranian Bt strains has also been
assessed for nematodes (Salehi Jouzani et al. 2008c). The nematicidal activity of the
mixture of spores and crystals of Bt strains harboring nematode-active cry genes was
determined against three nematode species, M. incognita (plant parasite), C. tenuis
and A. enoplus (free-living nematodes). The bioassays showed that two strains, YD5
and KON4, previously shown great insecticidal activity against lepidopteran pests
(Seifinejad et al. 2008), also have a great potential to control M. incognita. Therefore, these two Iranian Bt strains can be considered as appropriate candidates for the
development of bio-insecticides based on Bt. In another study, the nematicidal
activity of Iranian Bt strains isolated from soil in the tomato fields was evaluated
against M. javanica, root-knot nematode under in vivo and greenhouse conditions
(Ramezani Moghaddam et al. 2014). The Bt strains prohibited nematode egg
hatching and were toxic for M. javanica. The toxicity of two Bt strains containing
Cry14 protein was also evaluated against M. javanica under laboratory and greenhouse conditions (Baghaee and Moghaddam 2015). These Bt strains could reduce
10 Progress on the Bacterium Bacillus thuringiensis and Its. . .
415
Gracillariidae) to the commercial B. thuringiensis formulation (Bithiran®, Mehr
Asia Biotechnology Company, Iran) was determined under laboratory conditions
(Amiri-Besheli 2008). The studied Bt formulation demonstrated great insecticidal
activity against this pest and can be used in combination with bio-rational insecticides to increase the efficiency of leafminer management. The insecticidal activity of
certain Bt strains available in the Iranian Bt collection with lepidopteran-active genes
were assessed against the cotton bollworm, H. armigera. The toxicity of spore and
crystal mixtures of Bt strains was evaluated against the first instar larvae of
H. armigera. Two Bt strains (YD5 and KON4) were detected with great insecticidal
activity against the cotton bollworm (Seifinejad et al. 2008). Under laboratory
conditions, the insecticidal activity of spore and crystal suspensions of Iranian Bt
strains was assessed against P. brassica and C. pipiens. Some of the studied Bt
strains caused mortality higher than 75% on P. brassica and C. pipiens (Aramideh
et al. 2010). So, these Bt strains, can be considered for biological control of insect
pests. The insecticidal activity of four Iranian Bt strains isolated from soil were
assessed against P. xylostella, one the major pests of cruciferous crops, especially
cabbage fields in Tehran, and compared to that of Dipel as a commercial Bt based
insecticide (Deilamy and Abbasipour 2013). The pathogenicity of the spore and
crystal suspensions of Bt strains were investigated against third instar larvae of
P. xylostella, with Bt strain 87 found to be highly toxic for diamondback moth
(Deilamy and Abbasipour 2013).
The sub-lethal effects of B. thuringiensis subsp. kurstaki were evaluated on the
fitness and the biological parameters of H. armigera (Sedaratian et al. 2013).
Developmental time, fecundity, egg hatching percentage, net production rate (R 0 ),
intrinsic (r m ) and finite (λ) rates of increase, mean generation time (T ), mean
generation doubling time (DT) were adversely affected in the H. armigera treated
with sub-lethal concentrations of Bt. Sedaratian et al. (2013) concluded that biological performance and fitness of H. armigera were affected by exposing to the
sub-lethal concentrations of Bt.
Beyond the insect world, the biological activity of Iranian Bt strains has also been
assessed for nematodes (Salehi Jouzani et al. 2008c). The nematicidal activity of the
mixture of spores and crystals of Bt strains harboring nematode-active cry genes was
determined against three nematode species, M. incognita (plant parasite), C. tenuis
and A. enoplus (free-living nematodes). The bioassays showed that two strains, YD5
and KON4, previously shown great insecticidal activity against lepidopteran pests
(Seifinejad et al. 2008), also have a great potential to control M. incognita. Therefore, these two Iranian Bt strains can be considered as appropriate candidates for the
development of bio-insecticides based on Bt. In another study, the nematicidal
activity of Iranian Bt strains isolated from soil in the tomato fields was evaluated
against M. javanica, root-knot nematode under in vivo and greenhouse conditions
(Ramezani Moghaddam et al. 2014). The Bt strains prohibited nematode egg
hatching and were toxic for M. javanica. The toxicity of two Bt strains containing
Cry14 protein was also evaluated against M. javanica under laboratory and greenhouse conditions (Baghaee and Moghaddam 2015). These Bt strains could reduce
10 Progress on the Bacterium Bacillus thuringiensis and Its. . .
415