الفهرس 
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Abstract
Toxicity, levels of resistance, development of resistance and certain biochemical effects of certain pesticides on the Mediterranean fruit fly Ceratitis capitata were studied.
1. Toxicity of tested Pesticides
1.1. Spinosad (Conserve 0.024%CB)
Females of C. capitata were slightly more tolerable to the used pesticide than males on LC50, LC90 and LC99values, where females showed differently levels of tolerance to Conserve 0.024%CB. The respective values were 5635.24, 15558.62, 35604.21 ppm (for males) and 6033.97, 20395.43, 55041.84 ppm (for females). The toxicity line of males was nearly steeper than that of females.
1.2. spintoram (Radiant 12%SC)
Results indicated that males of the laboratory strain of the Mediterranean fruit fly were proportionally more susceptible than females. The values of LC50, LC90 and LC99 for males and females were 1285.43, 3096.39, 6339.96 and 1456.86, 3515.23, 7207.43 ppm, respectively. The slope values of Ld-p line were nearly the same (3.356 and 3.350).
1.3. Spinosad (Tracer 24% SC)
Both males and females of C. capitata laboratory strain were differently affected by Tracer 24 % SC showing values of LC50, LC90 and LC99 of 315.19, 364.55; 1893.36, 2763.15, and 8164.99, 14402.71 ppm, respectively. The slope value of toxicity lines of males was slightly more steeper (1.64) than that recorded for females (1.45).
1.4. Malathion (Malatox 57% EC)
The corrected mortalities for males were greatly closer to that of females. Thus, the values of LC50, LC90 and LC99 for males and females were 202.41, 998.85, 3669.59 and 222.18, 1101.70, 4063.32 ppm, respectively. The toxicity lines for the two sexes of the tested species were greatly parallel showing relatively the same slope values of 1.848 (for males) and 1.843 (for females).
1.5. Lambda-Cyhalothrin (Karilot gold 5% EC)
Toxicity for males and females of C. capitata laboratory strain gradually increased with the increase of Karilot gold 5% EC concentrations from 50 to 200 ppm. Mortality percentages for the two sexes were nearly the same. The values of LC50, LC90 and LC99, fore males were 95.97, 351.03 and 1010.31 ppm, respectively. The respective values for females were 98.78, 376.98 and 1123.14 ppm. The slope values of the Ld-p lines were 2.27 and 2.20 for males and females, respectively.
1.6. Dimethoate (Dimetox 40% EC)
The response of both males and females of the laboratory strain of the Mediterranean fruit fly at the used concentrations of Dimetox 40% EC were greatly the same showing values of LC50, LC90 and LC99 of 717.12, 4235.07, 18012 ppm (for males) and 851.32, 4399.41, 16781.9 ppm, respectively. The slope values of the toxicity line slightly differed recording 1.66 and 1.79 for that of males and females, successively.
2. Comparative Efficacy
2.1. Males
Lambda-cyhalothrin (Karilot gold 5% EC) was the most potent for males of C. capitata according to LC50, LC90 and LC99 values that recorded 95.97, 351.03 and 1010.31 ppm, respectively. But, Spinosad (Conserve 0.024% CB) was the lowest toxic compound recording the highest values were 5635.24, 15558.62 and 35604.21 ppm for LC50, LC90 and LC99,respectively. Spintoram (Radiant 12% SC) showed the steepest Ld-p lines recording the highest value of 3.36.
2.2. Females
Lambda-cyhalothrin (Karilot gold 5% EC) was the most efficient pesticide recording the lowest values of sub-lethal and lethal concentrations, but Spinosad (Conserve 0.024% CB) was the lowest toxic pesticide The values of LC50 ranged between 98.78- 6033.97 ppm. The values of both LC90 and LC99 ranged between 376.98- 20395.43 and 1123.14- 55041.84 ppm, respectively. Spintoram (Radiant 12% SC) had the steepest Ld-p lines (slope values 3.35), whereas Tracer 24% SC showed the flattest one recording slope value of 1.45.
3. Resistance Levels of Three Field Colonies to the Tested Pesticides
3.1. Spinosad (Conserve 0.024% CB)
Conserve 0.024% CB recorded the lowest levels of The mortality percentages of the males and females collected from strain of Sharkia governorate (29.41 for males and 6.66 for females) and showing the highest level of resistance ranged between 70.29 and 93.27% for males and females, respectively. The resistance levels of males of C. capitata was nearly the same both strains of Qaluobia and Behira governorates to Conserve 0.024% CB recording 59.59 and 58.84% comparing with control, respectively. But, in case of females the difference was relatively high, where females of Qaluobia governorate was more resistant to Conserve 0.024% CB than that of Behira governorate. The respective %resistance values were 79.79 and 65.04.The sensitivity of males and females of the Mediterranean fruit fly of the three tested governorates was relatively and nearly the same.
3.2. Spintoram (Radiant 12 % SC)
The sensitivity of males and females of the Mediterranean fruit fly of the three tested governorates to Radiant12 % SC was relatively low. The used pesticide gave 20, 38.23 and 33.33% mortality for male strains of Qaluobia, Behira and Sharkia governorates, respectively. But, the respective once for females were 0, 32.43 and 29.62%. The resistance percentages for males and females were 79.79, 100; 61.38, 67.33 and 66.33, 70.08 for Qaluobia, Behira and Sharkia governorates comparing with control, respectively. Males and females strain obtained from Qaluobia governorate were the most resistant to Radiant 12% SC. While strains of the other tested governorates were more susceptible to Radiant 12% SC by 1.29, 1.48 and 1.20, 1.42 times for males and females of Behira and Sharkia governorates, consecutively.
3.3. Spinosad (Tracer24 % SC)
The strain of Qaluobia governorate was completely resistant to Tracer 24% SC recording 100% resistance for both males and females. The mortality percentages of male and female strain of Behira governorate was 57.69 and 42.30, while the strain of Sharkia governorate recorded 28.57 and 23.80, respectively. Male resistance levels were 41.72 and 71.14. But, female resistance levels were higher than males in Behira and Sharkia governorates (57.27 and 75.95), successively. The resistance levels of males and females of Qaluobia governorate were relatively higher than that found in Behira and Sharkia governorate by 2.39, 1.74 and 1.40, 1.31 times, respectively.
3.4. Malathion (Malatox 57% EC)
The mortality percentages of Malatox 57% EC were 20, 0, 26.66, 11.11 and 42.3, 33.33 for both males and females of strains of C. capitata of Qaluobia, Behira and Sharkia, successively. The resistance percentages were 79.79, 100; 73.07, 88.77 and 57.27, 66.33 in males and female strains in the same three tested field governorates. There were no significantly differences in resistance levels of males and females of the tested governorates where, the strain of C. capitata of Qaluobia governorate was the most resistant to Malatox 57% EC and the strains of the other tested governorates (Behira and Sharkia) relatively showed 1.09, 1.12 and 1.39, 1.50 times resistant of males and females of Qaluobia governorate, respectively.
3.5. Lambda-cyhalothrin (Karilot gold 5% EC)
Both male and femaleof C. capitata strain collected from Qaluobia governorates were completely resistant to Karilot gold 5% EC. The mortality percentages of males and females of both Behira and Sharkia governorates were 28.57, 21.05 and 25.0, 10.0, recording resistance levels71.14, 78.73 (for Behira) and 74.74, 89.89 (for Sharkia governorate), respectively. The relative resistance of the latest two governorates was 1.40, 1.27 and 1.33, 1.11 times for males and females strains, respectively.
3.6. Dimethoate (Dimetox 40% EC)
The strain of C. capitata collected from Qaluobia governorate was the most resistant showing resistance levels 19.19 and 49.49 for males and females, respectively. The response of males of both Behira and Sharkia governorates was nearly the same which recorded 90.90 and 90 with resistance levels ranged between 8.18 and 9.09, respectively. While, in case of females, the mortality percentages slightly varied (88.57 and 81.25) to record resistance percentages of 10.53 and 17.92 for Behira and Sharkia governorates, respectively. There lative resistance of the tested males and females of C. capitata of both Behira and Sharkia governortes recorded 2.34, 4.69 and 2.11, 2.76 of that obtained for Qaluobia governorate, successively.
4. Comparative Resistance
4.1. Males
The resistance percentages of males of C. capitata differently varied according to the tested strains and the used pesticides. Dimethoate (Dimetox 40% EC) was the most effective compound showing the lowest values of % resistance for males of C. capitata of the three tested strains. Males of the Mediterranean fruit fly of Qaluobia strain were completely resistance to Spinosad (Tracer 24% SC) and Lambda-cyhalothrin (Karilot gold 5% EC) 100%.
4.2. Females
Females of C. capitata of Qaluobia colony strain were completely resistant to Spinosad (Tracer 24 % SC), Spintoram (Radiant 12% SC), Malathion (Malatox 57% EC) and Lambda-cyhalothrin (Karilot gold 5% EC). Except Spinosad (Conserve 0.024% CB) and Dimethoate (Dimetox 40% EC), showed 79.79 and 49.49 resistance percentages, respectively. The resistance percentages of females of C. capitata of Behira and Sharkia colonies were 65.04, 93.27; 57.27, 75.95; 67.33, 70.08; 88.77, 66.33; 78.73, 89.89 and 10.53, 17.92% for Spinosad (Conserve 0.024% CB), Spinosad (Tracer 24% SC), Spintoram (Radiant 12% SC), Malathion (Malatox 57% EC), Lambda-cyhalothrin (Karilot gold 5% EC) and Dimethoate (Dimetox 40% EC), respectively.
5. Resistance Development in C. capitata Adults
5.1. Spinosad (Conserve 0.024% CB)
The continuous treatment with LC20 of Conserve 0.024% CB to either males or females of the laboratory strain of C. capitata through eleven successive generations increased the resistance levels showing gradual decrement in mortality percentages which ranged between 29.88- 92.10 for males and 34.78- 94.73 for females. The resistance ratios of the second generation to the eleven one in proportion to the first generation gradually reduced from 0.99 to 0.32 for males, but those recorded for females decreased from 0.99 to 0.36. This means that the resistance level increased throughout the treated successive generations.
5.2. Spintoram (Radiant 12% SC)
Males of C. capitata completely susceptible to Radiant 12% SC from the first generation to the fourth one showing 100% mortality, but the susceptibility of females expanded to the 5th generation. The mortality percentages for males gradually decreased from the 4th generation (100) to the 8th one (55.55), but those recorded for females were reduced from 100 (in case of the 5th generation) to 77.27 (in case of the 8th generation). The mortality percentages for both males and females of C. capitata sharply decreased in case of the 9th generation to record 11.76% mortality for males and 25% mortality for females.
5.3. Malathion (Malatox 57%EC)
The mortality percentages of males and females of C. capitata treated with Malatox 57% EC through the successive seven generations ranged between 92.68- 100 and 90- 100, respectively. The mortality during the latest three generations (the 8th to 10th generations was sharply reduced to record 86, 85.41; 73.33, 63.3 and 27.16, 12.5 for males and females, respectively. Hence, the resistance ratio in proportional to the first generation ranged between 0.27- 0.98 (for males) and 0.13- 0.99 (for females).
5.4. Lambda-cyhalothrin (Karilot gold 5% EC)
The mortality percentages of both males and females of laboratory strain of C. capitata treated with Lambda-cyhalothrin gradually decreased through the ten successive generations. The % mortality of males was 95 (for the first generation) that gradually reduced to 37.5 (for the 10th generation), but the respective mortality percentages for females were 94.82 and 33.33. The resistance of both males and females of C. capitata to Lambda-cyhalothrin gradually increased via the consequent treatment throughout the consecutive generations. The resistance ratio of the successive generations to the first one ranged between 0.39- 0.98 (for males) and 0.35- 0.96 (for females).
5.5. Dimethoate (Dimetox 40% EC)
Both males and females of C. capitata through five successive generations showed complete susceptibility to Dimetox 40% EC recording resistance ratio of 1 for each. The sex generations gave high resistance level showing resistance ratio of 0.33 and 0.40 for males and females, respectively. The respective mortality percentages were 33.33 and 40.
6. Rate of Resistance
6.1. Spinosad (Conserve 0.024% CB)
The resistance rates of both males and females of the Mediterranean fruit fly to Conserve 0.024% CB differently varied through successive eleven generations. The highest rates for both males and females were recorded for the latest three generations (the 9th, 10th and 11th) of 0.09, 0.9; 0.19, 11 and 0.15, 0.18, respectively. The lowest rates of 0.01 and 0.007 were observed with the second and fourth generations of males and females, respectively.
6.2. Spintoram (Radiant 12% SC)
The resistance ratesof males and females of C. capitata to Radiant 12% SC ranged through successive nine generations between 0- 0.77 and 0- 0.52, respectively.
6.3. Malathion (Malatox 57% EC)
During the firstly successive seven generations, rates of resistance were very low (0- 0.02), but they began to increase from the 8th generation to the 10th one by 0.07, 0.13 and 0.46 (for males) and 0.05, 0.22 and 0.5 (for females) for the 8th, 9th and 10th generations, respectively.
6.4. Lambda-cyhalothrin (Karilot gold 5% EC)
The resistancer ates of males of C. capitata to Karilot gold 5% EC gradually increased with the increase of generations till the 6th one by 0.02, 0.03, 0.03, 0.06 and 0.1. But, the rate decreased to 0.05, 0.07, 0.07 for the 7th, 8th and 9th generations, respectively. The 10th generation showed the highest value of resistance rate recorded 0.18. Also, the same trend was took place with females that recorded rate of resistance to Karilot gold 5% EC of 0.04, 0.04, 0.03, 0.05 and 1 for the 2nd, 3rd, 4th, 5th and 6th generations, respectively. The resistance rate of females of C. capitata to Karilot gold 5% EC highly decreased to 0.01 for both the 8th and 9th generations, but it re-increased to 0.13 for the 10th generation.
6.5. Dimethoate (Dimetox 40% EC)
The resistance ratesof both males and females of C. capitata to Dimetox 40% EC were nil through the successive five generations, but they accidently showed high level of resistance rates of 0.67 and 0.6 for at the 6th generation for males and females, respectively.
6.6. Total rates of resistance
Spinosad (Conserve 0.024% CB) recorded 0.68 and 0.64 for males and females through eleven generations, respectively. But, Radiant showed 0.89 for males and 0.75 for females through nine generations. Malathion (Malatox 57% EC) and Lambda-cyhalothrin (Karilot gold 5% EC) gave resistance rates ranged between 0.73 & 0.61 (for males) and 0.87 &0.65 (for females) during ten successive generations, respectively. Finally Dimethoate (Dimetox 40% EC) recorded resistance rates were 0.67 and 0.60 for males and females through six successive generations, respectively. The rates of resistance for males were higher than that of females with Spinosad (Conserve 0.024% CB), Spintoram (Radiant 12% SC) and Dimethoate (Dimetox 40% EC), whereas in case of Malathion (Malatox 57% EC) and Lambda-cyhalothrin (Karilot gold 5% EC) the reverse was true.
7. Bio-chemical Effects of the tested compounds on different strains
7.1. Acid phosphatase activity
Statistical analysis and variance of data revealed that the differences in amounts of acid phosphatase between the examined colonies were highly significant in both males and females of the Mediterranean fruit fly. The amounts of acid phosphatase insignificantly varied in males of the three examined field colonies and higher than that of laboratory strain. The highest amount of acid phosphatase (29.07 mU /g.b.w.) was shown in males of Qaluobia field colony followed by Behira and Sharkia field colonies (28.50 and 26.90 mU /g.b.w., respectively) in case of females, the highest value of acid phosphatase amount (33.9 mU /g.b.w.) was significantly observed in Sharkia field colony strain. But, the lowest value of 20.83 mU/g.b.w. was recorded with females of Behira colony strain that insignificantly varied compared with females of laboratory strain (20.77 mU /g.b.w.). The activity ratios of the three tested field colonies were 1.36, 1.33, 1.26 fold (for males) and 1.11, 1.003, 1.63 fold (for females) of the laboratory strain.
7.2. Alkaline phosphatase activity
The differences in alkaline phosphatase between the examined colonies were statistically high significant. Qaluobia field colony strain significantly recorded the highest amounts of alkaline phosphatase in both males and females (932.67 and 1074.33 mU/ g.b.w) showing the highest values of activity ratio 3.63 and 5.63fold compared to laboratory strain, respectively. The amounts of alkaline phosphatase in males and females of both Behira and Sharkia colony strains were insignificantly differed (603.33, 463.0 and 553.67, 430.67 mU/ g.b.wt., respectively. The respective activity ratios were 2.35, 2.43 and 2.15, 2.25 fold compared tolaboratory strain, successively.
7.3. Effect on acetylcholine esterase activity
Amounts of acetylcholine esterase in males and females of the tested colony strains high significantly differed. The highest amounts of enzyme (396.67 and 317.67 AchBr/min/g.b.w.) were shown with males and females of Behira field colony strain recording the highest ratios of activity of 1.23 and 1.61 fold compared to those of the laboratory strain. The activity ratios of males and females of the other two used colony strains (Qaluobia and Sharkia) were 1.16, 1.60 and 1.14, 1.59 fold of the laboratory strain, successively.
7.4. Effect on total protein content
The amounts of total proteins in males and females of the used colony strains high significantly varied. Males of Behira colony strain significantly showed the highest amount of total proteins that insignificantly differed with those obtained with Qaluobia colony strain. The differences in amounts of total proteins in males of Sharkia colony strain insignificantly varied with those of Qaluobia colony strain compared to the laboratory one. But, females of Sharkia colony strain significantly recorded the highest amount of total proteins showing the highest value of activity ratio of 1.49 fold of the laboratory strain.