therefore, an alternative could be the use of B. thuringiensis,
but until now, there has not been any commercial
bioinsecticide produced using this bacterium to
control B. tabaci in this regard. One study tested nine
different Cry proteins from B. thuringiensis on B.
tabaci. This study showed that the nine proteins had no
effect because B. tabaci does not have the necessary digestive
proteases (Davidson et al., 1996). Another study
(Al-Shayji and Shaheen, 2008) reported the mortality of
50 to 60% of first-instar nymphs of B. tabaci treated
with a strain of B. thuringiensis isolated in Kuwait at a
concentration of 500 μg/mL. Our results are better than
those reported previously because mortalities of up to
90% were achieved in the third- and fourth-instar
nymphs treated with spore-crystal complexes at a concentration
of 40 μg/mL, which highlights the importance
of continuing to investigate the use of this entomopathogenic
agent to control this aggressive global
crop pest. Additionally, the spore-crystal complexes
produced in three of the tested media were as effective
as the chemical insecticide