**2.5 Chemical properties of palm wastes**

Date palm wastes were used as food for *P. opaca* larvae. The sampling of these wastes was carried out in April 2016 in Marrakesh area (Morocco). **Table 1** summarizes the main chemical composition of date palm wastes.

### **2.6 Main chemical composition of OMW**

Sampling of OMW was carried out in a semi-modern three-phase olive mill installed in Marrakesh (Morocco) and the samples were conserved at 4°C. The determination of the volatile matter (VM) was performed by differentiating between the dry matter (DM) obtained by evaporation at 105°C and the ash residue obtained from calcination at 550°C over a two-hour period.

#### **2.7 Phenolic compounds analysis**

### *2.7.1 Phenols extraction from OMW*

OMW total phenolic compounds were obtained by liquid–liquid extraction according to the method described by El Abbassi et al. [37]. HCl (2 M) was added to OMW

**493**

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

**Parameters Mean ± SD** Ph 7.03 ± 0.17 TOC (%) 40.80 ± 2.47 NTK (%) 1.06 ± 0.08 C/N 38.60 ± 4.88 Ashes (%) 29.80 ± 1.58

(mg/g) 738.00 ± 30.1

 (mg/g) 0.70 ± 0.08 Available phosphorus (μg/g) 9.00 ± 0.80

(×1000) 1.05 ± 0.75

samples (5 mL) to adjust pH to2.0.OMW were defatting using n-hexane and two extractions were performed with ethyl acetate. The aqueous ethyl extracts were dried at 40°C under reduced pressure via a rotary evaporator and then recovered in methanol (5 ml).

Estimation of the total phenol content was determined by the Folin–Ciocalteu calorimetric method [38] where gallic acid was used as the standard. Therefore, it was measured as gallic acid equivalent (GAE) and expressed as g of GAE/L of OMW.

HPLC analysis was conducted at the Center for Analysis and Characterization (Cadi Ayyad University, Marrakesh, Morocco) with C18 column (Eurospher II 100–5, 250 x 4.6 mm) in gradient system (eluting solution A = acetonitrile; eluting solution B = *o*-phosphoric acid/water (pH = 2.6), 5/95 v/v). A volume of 10 μl was injected at a flow rate of 1 mL/min and pressure of 117 bar. The characterization of phenolic compounds was carried out using their UV–Vis diode-array detector at a spectrum of 280 nm and their identification was performed by comparing their retention time (RT) with standards. Then these compounds were quantified through the calibration curve of the corresponding standards. The results obtained were expressed in g/L.

Sampling of larvae of *P. opaca* var. cardui Gyllenhal (**Figure 3**) was conducted according to section sampling techniques. The larvae were reared in round boxes (8 cm x 5 cm: diameter x height) containing a mixture of palm waste (150 g). The larvae culture was maintained in darkness at an optimal temperature between 25 and 30°C inside an incubator. The experiments were conducted in the same

The insecticidal activity of crude OMW and the two commercial insecticides (used as positive controls, Cordus and Kemaban 48 EC) to control *P. opaca* larvae was assessed by a spray toxicity bioassay conducted using 5 g of palm compost in

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

*TOC, total organic carbon; TKN, total Kjeldahl nitrogen.*

*Chemical characteristics of date palm waste.*

*2.7.2 Total phenolic content*

NH4 +

NO3 −

NH4 + /NO3 −

**Table 1.**

**2.8 Larvae cultures**

conditions as those for the cultures.

**2.9 Spray toxicity bioassay**

*2.7.3 OMW phenolic compounds identification*

*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*


#### **Table 1.**

*Biotechnological Applications of Biomass*

*P. dactylifera*. The breeding substrate was composed of a mixture of untreated natural soil and debris of dead wood, rotted wood and sawdust. Care was taken not to import diseases on bringing boxes of dry dung in breeding substrate in order to increase its acidity, which disadvantages the development of diseases. The breeding substrate was constantly renewed as soon as the feces of larvae appear in large quantities on the surface and more debris and wood in the rearing environment was observed. This breeding operation continued in incubators refrigerated and illuminated with controlled temperature and humidity. However, larvae are lucifugous (escape behavior of light); the optimum temperature is between 25 and 30°C. The nymphal hulls were placed in boxes with slightly damp peat. The duration of pupation varies according to the temperature supported by the larvae and also the male or female sex. The infected nymphal hulls were removed as soon as possible from the breeding

*Exploration of the* P. canariensis *palm crown using a scaffold (A); base of leaves (B and C).*

environment to avoid pathological contamination of the rest of the cocoons.

Date palm wastes were used as food for *P. opaca* larvae. The sampling of these wastes was carried out in April 2016 in Marrakesh area (Morocco). **Table 1** summarizes

Sampling of OMW was carried out in a semi-modern three-phase olive mill installed in Marrakesh (Morocco) and the samples were conserved at 4°C. The determination of the volatile matter (VM) was performed by differentiating between the dry matter (DM) obtained by evaporation at 105°C and the ash residue

OMW total phenolic compounds were obtained by liquid–liquid extraction according to the method described by El Abbassi et al. [37]. HCl (2 M) was added to OMW

**2.5 Chemical properties of palm wastes**

**2.6 Main chemical composition of OMW**

**2.7 Phenolic compounds analysis**

*2.7.1 Phenols extraction from OMW*

the main chemical composition of date palm wastes.

obtained from calcination at 550°C over a two-hour period.

**492**

**Figure 2.**

*Chemical characteristics of date palm waste.*

samples (5 mL) to adjust pH to2.0.OMW were defatting using n-hexane and two extractions were performed with ethyl acetate. The aqueous ethyl extracts were dried at 40°C under reduced pressure via a rotary evaporator and then recovered in methanol (5 ml).
