The partial measure of their harmful effects, and, thus,
The indiscriminate use of pesticides results in mortality of
beneficial insects, stimulation of the reproductive rate in certain pests, resistance
to pesticides and finally environmental pollution (Kumral et al. 2010; Cothran et al.,
Over 80 pesticides belonging to different chemical groups have been reported on
the development of resistance by T.
urticae (Van Leeuwen et al. 2010; Vassiliou and Kitsis 2013). Moreover, pesticides
commonly used are not specific and they frequently kill natural enemy
populations and may cause upset and resurgence of other pest populations
(Debach and Rosen, 1991; Pedigo, 1999). The widespread use of pesticides or
acaricides has eliminated many of the natural enemies of the T. urticae, resulting in a reduction of
predation pressure on mites (Wu et al., 2016). Furthermore, pesticide residue
problems also emerge (Mart´?nez-Ferrer
et. al. 2006).
In order to overcome
the disadvantages of pesticides, biological control is a good and economical
approach. Biocontrol agents such as coccinellides, cryopopids and syrphids have
been reported to be effective for controlling the mite (Singh and Malhotra,
1979, Saharia, 1981, Kalra, 1988 and Shukla, 1990). The coccinellids are
extremely diverse in their feeding habits, and many of these are predaceous and
beneficial from the view point of biological control of pests. The seven
spotted ladybird beetle, Coccinella septempunctata L. (Coleoptera:
Coccinellidae), is a generalized predator that are able to feed on many
phytophagous insects and mites in cultivated crops (Bompardet al. 2013, Mirandeet al.
2015, Perez-Hedo and Urbaneja 2015, Saeed et
al. 2015, Biondiet al. 2016). Many
coccinellids have been frequently used in IPM and biological control program
(Obrycki and Kring 1998). In many cases, the performances of these insect in
the field conditions has not been promising and the use of pesticides remains
the principal solution. However,
selective use of pesticides that are compatible with natural enemies may
conserve the populations of predators and get effective control (Talebiet al.
2008; Radcliffe et al.2009).
Most of the papers have focused on measuring the acute toxicity of the pesticides.
However, this may only be a partial measure of their harmful effects, and, thus,
sublethal effects on arthropod physiology and behaviour should also be
considered for a complete analysis of their impact. Regarding beneficial
species (predatory insects), there is lack of information as to what extent
they are affected by pesticide application (Michaud 2002).
In this context, the research program was undertaken with the following