**2.1 Study area and plant material**

This study was conducted during the period of 2014–2016 in the oasis of Marrakesh located in the central region of Morocco and the oasis of Errachidia situated in the southeastern part of the country. The majority of their territory presents arid climate, hot summer and cold winter. Palms (*Phoenix*) constitute one of the important botanical families, and include some of the world's most important economic plants. In North Africa regions, dates production provides jobs for estimated around 50 million people [32]. It plays by now an undeniable role in maintaining human populations in arid regions where natural resources are limited and living conditions are difficult [32, 33]. Like in Zagora, Errachidia, Ouarzazate which are located in the Draa-Tafilalet region. It is built on terraces, crowned by an old Glaoui kasbah of a hill and surrounded by a major oasis of palm grove. This includes in particular the biosphere reserve of the oases of south-eastern Morocco [34], which forms an agglomeration of ksours (small castles). This area is located in an

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*Use of Olive Mill Wastewaters as Bio-Insecticides for the Control of* Potosia Opaca *in Date Palm…*

environment covered by vegetation and many dunes were transformed into regs (vast stone expanses) where the vestiges of khetaras (old local irrigation system) are still visible. As Marrakesh city, the area is under a semi-arid climate regime characterized by relatively cold and humid winters and hot and dry summers with a large diurnal temperature range [35]. This study was performed on *P. dactylifera* and *P. canariensis*. 60-year-old trees with a diameter of 70–90 cm were selected for larvae sampling (**Figure 1**). Analyzed leaves were 4–5 m long with 80–100 segments on each side of the spine. No specific permissions were required for these locations and activities. The field studies did not involve endangered or protected species. The pathogen presence was visually confirmed. No plants were available at very early stage of infection.

The present study used augers to perform localized sampling and perform microbiological isolates. To deepen the diagnosis of *P. canariensis*, we made samplings of rachis, leaflets palms, dry and green leaf bases at the crown. We have carried out cultures and incubation of extracts of rachis (1 cm) and palm leaves

During the exploration of the palm crown, using a scaffold (**Figure 2A**), a number of larvae (white grubs) sluggish and arched with strong mandibles were harvested at the base of green and/or dead rachis. Similarly, insect larvae were removed from the base of green and dried palms for laboratory breeding in incubators with controlled conditions of temperature, humidity and photoperiod. Dead rachis (**Figure 2B** and **C**) were brought back to the laboratory to explore them further and also put them in terrariums to ensure the follow-up and development of the larvae trapped inside the hope of having imagos (adult forms). Identification of larvae was performed according to the key proposed by Mico and Galante [36].

The collected larvae were immediately placed into breeding boxes; transparent, with holes on the sides and on the top of the boxes to ensure oxygenation and avoid asphyxiation. The holes on the boxes are closed with a fabric scrim (muslin type). Rectangular boxes were used for rearing larvae harvested from *P. canariensis* and

*DOI: http://dx.doi.org/10.5772/intechopen.93537*

**Figure 1.**

**2.2 Phytopathological analysis and fungi isolation**

*Pictures of* P. dactylifera *(A) and* P. canariensis *(B) in Marrakesh city.*

**2.3 Sampling techniques and prospecting the crown of palm**

puny on selective and non-selective media.

**2.4 Breeding of larva and nymphs**

*Use of Olive Mill Wastewaters as Bio-Insecticides for the Control of* Potosia Opaca *in Date Palm… DOI: http://dx.doi.org/10.5772/intechopen.93537*

**Figure 1.** *Pictures of* P. dactylifera *(A) and* P. canariensis *(B) in Marrakesh city.*

environment covered by vegetation and many dunes were transformed into regs (vast stone expanses) where the vestiges of khetaras (old local irrigation system) are still visible. As Marrakesh city, the area is under a semi-arid climate regime characterized by relatively cold and humid winters and hot and dry summers with a large diurnal temperature range [35]. This study was performed on *P. dactylifera* and *P. canariensis*. 60-year-old trees with a diameter of 70–90 cm were selected for larvae sampling (**Figure 1**). Analyzed leaves were 4–5 m long with 80–100 segments on each side of the spine. No specific permissions were required for these locations and activities. The field studies did not involve endangered or protected species. The pathogen presence was visually confirmed. No plants were available at very early stage of infection.
