*3.5.2 Mortality rate of treated larvae*

Mortality due to crude OMW was 33, 67 and 100% at 216, 224 and 456 h, respectively (**Table 4**). In the same way, Kemaban exhibited 33% mortality at 192 and 174 h with application of doses of 0.5 and 1 μL/mL, respectively. The mortality


#### **Table 3.**

*OMW phenolic compounds determined by HPLC.*

**Figure 7.** *Weight loss of* P. opaca *larvae treated with crude OMW and different doses of commercial insecticides.*

**499**

*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*

**Time after treatment (Hour)**

**Treatment**

Control Crude OMW

95 mg/mL Cordus 0.5 μL/mL

1 μL/mL Kemaban

0.5 μL/mL

1 μL/mL

**Table 4.**

*Percentage of dead Potosia opaca larvae for each treatment.*

0.00 0.00

0.00

0.00

33.33

33.33

66.67

66.67

100

100

100

100

0.00

0.00

0.00

33.33

33.33

33.33

66.67

100

100

100

0.00 0.00 0.00

33.33

33.33

66.67

66.67

100

100

100

100

100

100

0.00

33.33

66.67

66.67

66.67

100

100

100

100

100

0.00

0.00

0.00

0.00

0.00

33.33

33.33

66.67

66.67

100

**0** 0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

**144**

**146**

**174**

**192**

**198**

**216**

**218**

**224**

**288**

**456**

*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 4.** *Percentage of dead Potosia opaca larvae for each treatment.*

*Biotechnological Applications of Biomass*

result of larval death.

*3.5.2 Mortality rate of treated larvae*

**Peak Retention time** 

**(min)**

*OMW phenolic compounds determined by HPLC.*

two active substances, whose weight loss was similar to that of OMW for the two doses applied. The greatest weight loss over the first three days compared to the other treatments was achieved at a dose of 1 μL/mL, which resulted from the slow decrease in weight. Then, a more or less similar weight loss was observed for both doses. Kemaban insecticide is formed by a single active substance and resulted in significant weight loss at both doses compared to control and other treatments (Cordus and OMW) (**Figure 7**). Significant weight loss was seen during the first 4 days at a dose of 1 μL/mL of Cordus compared to 0.5 μL/mL of Kemaban. Thereafter, weight loss was found to be almost similar until 174 h, and then became slight and stable at a dose of 1 μL/mL until 224 h. The stability was the

Mortality due to crude OMW was 33, 67 and 100% at 216, 224 and 456 h, respectively (**Table 4**). In the same way, Kemaban exhibited 33% mortality at 192 and 174 h with application of doses of 0.5 and 1 μL/mL, respectively. The mortality

 3.950 654.660 0.146 Gallic acid 9.967 3191.702 0.248 Hydroxytyrosol 13.317 2005.142 0.201 Tyrosol 14.450 53.766 0.122 Hydroxybenzoic acid 15.167 186.037 0.128 4-dihydroxybenzoic acid 16.117 102.685 0.124 Vanillic acid 17.317 42.461 0.122 Caffeic acid 22.250 53.637 0.122 Coumaric acid 30.933 39.469 0.122 Oleuropein 44.417 674.747 0.147 Quercetin

**Concentration (g/L)**

**Compounds**

**Area (mAU)**

*Weight loss of* P. opaca *larvae treated with crude OMW and different doses of commercial insecticides.*

**498**

**Figure 7.**

**Table 3.**


*b SE, standard error.*

*c Df, degree of freedom.*

#### **Table 5.**

*LT50 and LT90 values of OMW and two positive controls applied by using spray toxicity bioassay to control Potosia opaca larvae.*

rate was 100% when larvae were treated with Kemaban at 218 and 216 h for 0.5 and 1 μL/mL, respectively. Otherwise, mortality of larvae treated with Cordus was significantly higher compared to other treatments. After 144 and 146 h, the effect began with doses of 1 and 0.5 μL/mL, respectively. However, larvae treated with OMW, Kemaban and Cordus started to die for the first time from day 9, 8 and 6 respectively. In contrast, the two commercial insecticides caused 100% mortality within 8 (Cordus) and 9 (Kemaban) days for all doses tested, compared to OMW which showed 33 and 100% mortality after 9 and 19 days, respectively.

### *3.5.3 Spray toxicity bioassay*

Boutaj et al. [31] reported that OMW showed insecticidal activity to control *P. opaca* larvae with LT50 and LT90 values of 245 h and 324 h, respectively (**Table 5**). Furthermore, a positive correlation was found between treatments and the duration of exposure (Letal time to kill 50% and 90% of the population). The highest efficiency was recorded for Cordus insecticide with LT50 of 160 h and 173 h for 1 and 0.5 μL/mL doses, respectively and LT90 of 199 h and 211 h for 1 and 0.5 μL/mL doses, respectively. Median lethal times (LT50 and LT90) generally decrease when insecticide concentrations increase. The least effectiveness was observed in *P. opaca* larvae for crude OMW. However, the results were close to Kemaban at a dose of 0.5 μL/mL.
