**1. Introduction**

Recently, plant protection strategy has recommended, minimizing the use of chemical pesticides. Therefore, studying the side effect of insecticides on the natural enemies is highly required to exclude the detrimental effects on the natural enemies. Every crop is infested by various pests; some but not all of them may be controlled by biological means using pathogens, predators, parasitoids and spiders. But to achieve a satisfactory control of complexes of pests, selective pesticides are also indispensable. In fact, they are a prerequisite of Integrated Pest Management.

The integration of chemical and biological control is often critical to the success of an integrated pest management (IPM) program for arthropod pests (Smilanick et al. 1996; El-Wakeil & Vidal 2005; El-Wakeil et al. 2006; Volkmar et al. 2008). In contrast with nonsystemic insecticides, many systemic insecticides and their metabolites are claimed to be fairly safe for beneficial in‐ sects because direct exposure to these chemicals occurs when insects feed on plant tissue. How‐ ever, systemic insecticides can potentially contaminate floral and extrafloral nectar when systemically distributed throughout the plant (Lord et al. 1968) and cause high mortality to nec‐ tarfeeding parasitoids for as long as some weeks after insecticide application (Stapel et al. 2000).

Most biological control agents, including predators, parasitoids and spiders, at work in the agricultural and urban environments are naturally occurring ones, which provide excellent regulation of many pests with little or no assistance from humans. The existence of naturally occurring biological control agents is one reason that many plant-feeding insects do not ordinarily become economic pests. The importance of such agents often becomes quite

© 2013 El-Wakeil et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 El-Wakeil et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

apparent when pesticides applied to control one pest cause an outbreak of other pests because of the chemical destruction of important natural enemies. There is great potential for increasing the benefits derived from naturally occurring biological controls, through the elimination or reduction in the use of pesticides toxic to natural enemies.

insecticide significantly affected the longevity or reproductive capacity of emerged females, or the sex ratio of their progeny. This study revealed that application of these insecticides should be cautiously through season to conserve natural or released populations of *T. grandis*. Adult females of *T. grandis* usually produce the majority of offspring in the first few days after emergence. Proportion of male offspring produced by *T. grandis* in the early life span of the parasitoid is higher in the treatments than control that will result in a higher proportion

Side Effects of Insecticides on Natural Enemies and Possibility of Their Integration in Plant Protection Strategies

http://dx.doi.org/10.5772/54199

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**Figure 1.** Proportion of male offspring produced by *Trissolcus grandis* adults emerged from treated parasitized eggs at

It is very important studying the insecticide side effects on egg parasitoids. The first study on side-effects of neem products on egg- parasitoids was conducted by Joshi et al. (1982) in India. These authors applied a 2% aqueous NSKE (Neem Seed Kernel Extract) on the egg masses of the noctuid *Spodopteru litura.* The egg parasitoid *Telenomus remus* was not repelled from egg laying. When the treatment was carried out before egg laying of the parasitoid, the emergence of adult parasitoids was normal but their duration of life was shorter than that of controls. On the other hand, spraying with NSKE after oviposition of *T. remus* increased the fecundity of the wasps developed in treated eggs and prolonged their life as compared with that of

*Trichogramma* genus is a tiny parasitoid and some species are susceptible for chemicals. In both cases using insecticides alone or compatible with *Trichogramma*, there is a side effect on the later as studied by by Shoeb (2010), who mentioned that effect of five insecticides, Profect (w.p.), CAPL- 2 ( mineral oil), Lambda-cyhalothrin, Spinosad, and Fenitrothion (Sumithon)

untreated controls; similar results were also reported by Golec (2007).

of males in the insecticides treatments (Fig. 1).

pupal stage and control (after Saber et al. 2005)

*2.1.2. Telenomus remus*

*2.1.3. Trichogramma species*

The main objective of this book chapter studying the insecticide side effects on development, parasitism or predation efficacy and emergence capacity as well as to preserve effective biological control agents is a combination of tactics including an understanding of the biology and behaviour of arthropods (parasitoids, predators and spiders), detailed monitoring of life history and population dynamics of pests and natural enemies, employment of selective pesticides, application only when absolutely necessary, basing chemical control on established economic injury levels and application at the least injurious time.
