*3.2.4.2 Insecticidal control*

#### *3.2.4.2.1 Botanical insecticides*

The botanical insecticide is an alternative to synthetic insecticide for the management of pests as it provides little or no threat to the environment, ecosystem, and human health [268]. The antifeedant activity of azadirachtin was evaluated against LBF larvae [269], azadirachtin is most important natural antifeedant, which inhibits the feeding and indirectly causes death of insect due to starvation [270]. Another approach to spray the plant leaves is with distasteful substance derived from plant extracts. According to Vattikonda et al. [271], forskolin, a labdane diterpene derived from the plant *Coleus forskohlii* showed an antifeedant activity at the concentration of 200 ppm. Similarly, betulinic acid from *Ziziphus jujube* [271] and andrographolide from *Andrographis paniculate* [272] also displays strong antifeedant activity against LBF.

## *3.2.4.2.2 Microbial insecticides*

The pathogen can be used as biological control agent and is integrated with natural enemies to protect the crop from insect pest damage. The isolates of *Isaria fumosorosea* (Ifr1 and Ifr2) showed their potential to kill the LBF larvae by causing 72.23 and 61.90% mortality after exposure of 8 days at dose of 10<sup>8</sup> spores/ml concentration, respectively [273]. The one of most commonly used microorganism is *Bacillus thuringiensis* (Bt), which is highly effective against lepidopteron larvae [274]. Osouli and Afsharmanesh [275] found that a strain of *Bacillus subtilis* (M419) produces secondary metabolites especially lipopeptide biosurfactants that inhibit the growth and cause larval mortality in LBF.

#### *3.2.4.2.3 Synthetic insecticides*

The synthetic pesticides are used in large scale for control of insect pests worldwide because of high efficacy and low cost. However, the regulation of these

*Ecology, Biology, Damage, and Management of Sucking and Chewing Insect Pests of Citrus DOI: http://dx.doi.org/10.5772/intechopen.109846*

compounds is also increasing globally due to their concern about toxicity and environmental safety [276]. The cypermethrin has been proven more toxic for larvae of LBF than that of neem extract of *Azadirachta indica*, while deltamethrin was found less effective than *Azadirachta*; hence, cypermethrin could be a good candidate against LBF in citrus orchards [277]. Haque et al. [278] reported that LBF treated with spinosad and chlorfenapyr showed lowest rate of infestation, hence are highly effective and their use could result in highest yield of citrus due to significant suppression of LBF. The application of spinosad is environmentally benign and cost effective than that of chlorfenapyr. It can be suggested that grower should use spinosad for the management of LBF larvae in nurseries and gardens. The juvenile insect growth regulator (IGR) known as diofenolan which severely hampers the normal development, growth, and metamorphosis of LBF larvae can also be incorporated in IPM for better control [279]. Another IGR known as diflubenzuron is also effective in controlling the LBF; it not only reduces the growth but also causes morphological deformities in insect [280].

#### *3.2.4.3 Mechanical control by hand picking*

The hand picking is most practical technique under certain conditions such as in case of cheap labor availability, conspicuous, and large egg masses, when insects are too sluggish, have congregate behavior and easily accessible to the pickers. Hand picking of LBF larvae is efficient method to reduce the infestation particularly in nurseries and home gardens [281].

## **4. Concluding remarks**

In this chapter, important features of the main citrus pests were demonstrated. Nowadays, there are many insects that are pests of citrus and a few ones were wellstudied, reinforcing that other species need to be investigated. Thus, the studies on biology, ecology, and management of citrus pests are necessary, mainly those that may produce data useful to control and mitigate damages caused by the pests. In addition, field effectiveness and climatic adaptations in different geographic regions with high citrus crop activity should be evaluated in order to contribute for pest control. Furthermore, the search for environmental friendly new molecules, natural enemies, resistant plants, and technological approaches should be stimulated.
