الفهرس 
ACKNOWLEDGMENT
Evaluation of some biological control agents againstOnly 14 pages are availabe for public view
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Abstract
5.1- Identification of Culex mosquitoes
Three species of Culex were identified in Assiut area using agarose gel analysis of PCR amplified products. At Al-Azhar University area, Cx. pervigilans was identified (PCR produced in bp was 713). In Arab-Almadabegh area, Cx. quinquefasciatus was identified (PCR product in bp was 623), whereas Cx. p. pallens was recorded at El-Ghorieb area (PCR product in bp was 648).
5.2- The predatory efficiency of four aquatic predators against mosquito larvae and pupae under temperature, salinity, breeding water and pH.
a- Temperature
The predatory efficiency of four aquatic predators was evaluated against culicine mosquito larvae and pupae at 15, 25 and 35°C under laboratory condition, results revealed that:
1- The average number of mosquito larvae consumed by one tadpole ranged between 0.00 and 1.66 with an average of 0.36 larva /day at 15°C, 0.66 and 16.0 with an average of 9.33 larva /day at 25°C and 0.00 and 18.0 with an average of 5.4 at 35°C. Significant variation in consumption rate was recorded between the three temperatures tested. The highest consumption rate was recorded at 25°C followed by 35°C, then 15°C.
2- The average consumption rate of one nymph of odonate species Orthetrum spp. from mosquito larvae varied significantly between the three temperature degrees tested, the highest predation rate was recorded at 35°C (15.66 to 42.66 with an average of 25.73 larva /day), followed by 25°C (12.66 to 35.66 with an average of 33.1 larva /day), while the lowest average predation rate was recorded at 15°C (3.0 to 11.0 with an average of 6.16 larva /day).
The average consumption rate from pupae was significantly higher at 35°C (1.66 to 10.0 with an average of 6.60 pupa/day) than that at 25°C (1.33 to 6.66 with an average of 4.1 pupa /day) or 15°C (0.33 to 3.00 with an average of 1.13 pupa /day).
The average consumption rate of Orthetrum spp. from mosquito pupae, was much lower than that from larvae.
3- As for the backswimmer bug predator A. sardea, the average consumption rate of one nymph from 4th instar larvae of culicine mosquitoes was significantly higher at 35°C (8.66 to 17.33 with an average of 14.83 larva /day) than that at 25°C (8.0 to 17.33 with an average of 12.7 larva /day) and 15°C (3.33 to 18.0 with an average of 9.3 larva /day).
The average consumption rate of the predator nymph from mosquito pupae was higher at 35°C (1.33 to 6.66 with an average of 3.55 pupa /day) than that at 25°C (1.33 to 4.0 with an average of 2.13 pupa /day) and 15°C (0.00 to 3.0 with an average of 1.53 pupa /day) with no significant variation.
At the three temperature degrees, the consumption rate from larvae was much higher than that from pupae.
4- For the aquatic predator S. selecta, the average consumption rate from mosquito larvae or pupae was much lower than that recorded for the previous three predators. The relatively high average consumption rate from larvae was recorded at 35°C (0.00 to 2.66 with an average of 1.89 larva / day) and for pupae it was at 25°C (0.00 to 3.0 with an average of 1.16 pupa / day).
5- Generally, irrespective of the temperature degrees the predator Orthetrum spp. was the most active one for devouring mosquito larvae or pupae.
b- Salinity:
The predatory efficiency of four aquatic predators was evaluated against culicine mosquito larvae and pupae at salinity levels 0.5, 1.0 and 2.0 gm sodium chloride /L water in laboratory, results revealed that:
1- The average consumption rate of one tadpole B. regularis from mosquito larvae was higher at salinity level 2.0 gm NaCl /L water (4.00 to 17.33 with an average of 11.40 larva /day) than that at 1.0 gm NaCl / L water (3.33 to 15.33 with an average of 10.53 larva /day) or 0.5 gm NaCl /L water (2.66 to 17.66 with an average of 10.40 larvae /day) with no significant variation.
2- The average consumption rate of one nymph of odonate species Orthetrum spp. from mosquito larvae was higher at salinity 1.0 gm NaCl /L water (21.66 to 49.33 with an average of 33.50 larva /day) than that at salinity 0.5 gm NaCl /L water (9.33 to 46.66 larvae with an average of 32.63 larva / day) or salinity 2.0 gm NaCl /L water (7.66 to 50.0 with an average of 27.53 larva / day) with no significant variation.
The average consumption rate from pupae was higher at salinity 2.0 gm NaCl /L water (2.0 to 5.66 with an average of 3.73 pupa / day) than that at 0.5 gm NaCl /L water (1.0 to 5.0 with an average of 2.83 pupa / day) or 1.0 gm NaCl /L water (1.66 to 4.66 with an average of 3.20 pupa /day) with no significant variation.
3- As for the backswimmer bug predator A. sardea, the average consumption rate of one nymph from 4th instar larvae of culicine mosquitoes was higher at salinity level 2.0 gm NaCl /L water (6.66 to 18.66 with an average of 14.37 larva / day) than that at 1.0 gm NaCl /L water (10.0 to 18.33 larvae with an average of 14.10 larva /day) or 1.0 gm NaCl / L water (5.0 to 19.0 larva with an average of 14.03 larva / day) with no significant variation.
The average consumption rate of the predator nymph from mosquito pupae was higher at 1.0 gm NaCl /L water (0.66 to 7.66 with an average of 3.89 pupa / day) than that at salinity 2.0 gm NaCl /L water (0.66 to 6.66 with an average of 3.56 pupa / day) or salinity 0.5 gm NaCl / L water (1.0 to 8.0 pupae with an average of 3.33 pupa / day) with no significant variation.
4- For the aquatic predator S. selecta the average consumption rate from mosquito larvae or pupae was much lower than that recorded for the previous three predators. The relatively high average consumption rate from larvae was recorded at salinity level 1.0 gm NaCl /L water (0.33 to 4.0 with an average of 1.80 larva /day) and for pupae it was at salinity level 0.5 gm NaCl /L water (0.00 to 3.66 pupae with an average of 1.36 pupa / day) with no significant variation at all salinity levels.
5- Generally, irrespective of the salinity levels the predator Orthetrum spp. was the most active one for devouring mosquito larvae, but A. sardea was the most active one against pupae.
c- Breeding water:
The predatory efficiency of four aquatic predators was evaluated against mosquito larvae and pupae in distilled, irrigation and cesspool water in laboratory, results showed that:
1- The average consumption rate of one tadpole from mosquito larvae varied significantly between the three types of breeding water tested, the highest predation rate was recorded in irrigation water (3.00 to 19.66 with an average of 10.81 larva /day) followed by distilled water (4.0 to 16 with an average of 8.57 larva /day). However, tadpole live for one day only in cesspool water and consumed 4 mosquito larvae.
2- The average consumption rate of one nymph of odonate species Orthetrum spp. from mosquito larvae varied significantly between the three types of breeding water tested, the highest predation rate was recorded in distilled water (6.0 to 35.66 with an average of 22.44 larva/ day), followed by irrigation water (1.0 to 25.33 with an average of 13.14 larva /day), while the lowest predation rate was recorded in cesspool water (3.33 to 21.0 with an average of 11.87 larva /day).
The average consumption rate from pupae was higher in irrigation water (5.33 to 6.66 with an average of 5.43 pupa /day) than that in distilled water (2.0 to 5.66 with an average of 3.83 pupa /day) or in cesspool water (0.00 to 2.66 with an average of 1.38 pupa /day) with no significant variation.
The average consumption rate of Orthetrum spp. from mosquito pupae was much lower than that from larvae.
3- As for the backswimmer bug predator A. sardea, the average consumption rate of one nymph from 4th instar larvae of culicine mosquitoes was higher in distilled water (1.33 to 15.33 with an average of 7.50 larva / day) than that in cesspool water (3.0 to 11.66 with an average of 7.27 larva / day) or in irrigation water (2.33 to 8.0 with an average of 6.03 larva / day) with no significant variation.
The average consumption rate of the predator nymph from mosquito pupae was higher in cesspool water (1.0 to 9.33 with an average of 4.94 pupa / day) than that in irrigation water (1.33 to 7.33 with an average of 3.56 pupa / day) or in distilled water (1.0 to 8.33 with an average of 3.53 pupa / day), with no significant variation.
At the three types of breeding water, the average consumption rate from larvae was much higher than that from pupae.
4- For the aquatic predator S. selecta the average consumption rate from mosquito larvae or pupae was much lower than that recorded for the previous three predators. The relatively high average consumption rate from larvae was recorded in cesspool water (0.00 to 3.0 with an average of 1.4 larva / day), and for pupae it was in irrigation water (0.00 to 3.0 with an average of 1.24 pupa / day).
5- Generally, irrespective of the breeding water, the predator Orthetrum spp. was the highest active ones for devouring mosquito larvae, while the predator A. sardea was the highest active ones against pupae in cesspool water.
d- pH:
The predatory efficiency of the four aquatic predators was evaluated against mosquito larvae and pupae under 3 different of pH levels in laboratory, results revealed that:
1- The average consumption rate of one tadpole B. regularis from mosquito larvae varied significantly between pH, 11and 7 or 9, the highest predation rate was recorded at pH 7.0 (3.0 to 14.66 larvae with an average of 8.83 larva / day), followed by pH 9.0 (1.66 to 17.0 larvae with an average of 8.0 larva / day) while the lowest predation rate was recorded at pH 11 (1.00 to 5.66 with an average of 3.0 larva / day).
2- The average consumption rate of one nymph of odonate species Orthetrum spp. from mosquito larvae varied significantly between the 3 different pH levels tested, the highest predation rate was recorded at pH 7.0 (6.00 to 41.0 larvae with an average of 25.03 larvae /day) , followed by pH 9.0 (9.00 to 27.33 larvae with an average of 19.87 larva / day), while the lowest predation rate was recorded at pH 11 (0.66 to 16.33 larvae with an average of 7.0 larva / day).
The average consumption rate from pupae was higher at pH 7 (2.33 to 5.66 pupae with an average of 3.83 pupa / day), followed by pH 11 (2.33 to 4.33 pupae with an average of 3.33 pupa / day) then pH 9.0 (2.66 to 4.33 pupae with an average of 3.14 pupa /day), with no significant differences.
The average consumption rate of Orthetrum spp. from mosquito pupae was much lower than that from larvae.
3- As for the backswimmer bug predator A. sardea, the average consumption rate of one nymph from 4th instar larvae of culicine mosquitoes was higher at pH 9 (3.0 to 12.33 larvae with an average of 7.46 larva / day) than that at pH 11 (3.66 to 11.33 larvae with an average of 7.10 larva / day) or pH 7.0 (3.66 to 10.33 larvae with an average of 5.96 larva /day) with no significant differences.
The average consumption rate of the predator nymph from mosquito pupae was significantly higher at pH 11 (1.00 to 11 with an average of 5.36 pupa /day) than that pH 9.0 (1.66 to 7.0 with an average of 3.59 pupa / day) or pH 7.0 (0.66 to 9.0 with an average of 3.23 pupa / day).
4- For the aquatic predator S. selecta, the average consumption rate from mosquito larvae or pupae was much lower than that recorded for the previous three predators. The relatively high average consumption rate was recorded at pH 7 for larvae (0.00 to 1.66 with an average of 0.93 larva / day), and pupae (0.33 to 3.0 with an average of 1.33 pupa / day).
5- Generally, irrespective of the pH levels, the predator Orthetrum spp. was the highest active ones for devouring mosquito larvae and A. sardea was the lowest active ones against pupae. So, nymphs of Orthetrum may be recommended to use as an element of biological control agents for successful mosquito control.
5.3- Larvicidal activity of some isolates extracted from P. nigrum and M.hortensis against 4th instar larvae and pupae of Cx. pipiens under laboratory condition:
a- Larvae:
Five isolates, three extracted from M. hortensis and two extracted from P. nigrum were evaluated for their larvicidal activity against 4th instar larvae of Cx. pipiens under laboratory condition, results showed that:
1- The LC50, and lower and upper confidence limits value of -terpinene extracted from M. hortensis were 0.896 and 0.797 and 0.992 mg/ml, respectively. The correspondence values for LC90 were 1.625 and 1.419 and 1.998 mg/ml. The slope value of LCP line was 4.96.
2- For the isolate 4-terpineol, the LC50, LC90, and their lower and upper confidence limits were, 0.338, 0.302 and 0.374; and 0.59, 0.511 and 0.747 mg/ml, respectively. The slope value was 5.28. According to LC50 and LC90 values, the isolates 4-terpineol was much toxic to mosquito larvae than -terpinene.
3- The LC50, LC90, and their lower and upper confidence limits of the isolate piperine extracted from P. nigrum were 0.053, 0.037 and 0.069; and 0.236, 0.164 and 0.441 mg/ml, respectively. The slope of LCP line was 1.96.
4- The LC50 and its lower and upper confidence limits of volatile oil extracted from M. hortensis were 0.489 and 0.444 and 0.538. The corresponding values for LC90 were 0.879 and 0.748 and 1.179 mg/ml. The slope value was 3.77.
5- The LC50 and its lower and upper confidence limits of the isolate alkaloid extracted from P. nigrum were 0.027, 0.022 and 0.031 mg/ml respectively. The corresponding values for LC90 were 0.067, 0.054 and 0.094 mg/ml. The slope of LCP line was 3.51.
6- Comparing the toxicity of the five isolates according to LC50 and LC90 value, it might be concluded that, alkaloid extracted from P. nigrum, was the highest toxic one against mosquito larvae, followed by piperine. On the other hand, according to slope values of LCP lines of the five isolates, Cx. pipiens larvae showed relatively more homogeneity response to 4-terpineol.
7- b- Pupae:
1- Two isolate compounds, alkaloid and volatile oil were evaluated for their toxicity against Cx. pipiens pupae. The LC50 and its lower and upper confidence limits were 0.049, 0.037 and 0.059 mg/ml. The corresponding values for LC90 were 0.199, 0.164 and 0.270 mg/ml. The slope of LCP line was 5.48.
2- For the volatile oil isolate, the LC50 and its lower and upper confidence limits were 0.596, 0.525 and 0.666 mg/ml. The corresponding values for LC90 were 1.303 and 1.063, 1.918 mg/ml. The slope of LCP line was 5.72.
3- According to the LC50 and LC90 values, alkaloid was more toxic than volatile oil against mosquito pupae.