الفهرس 
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Abstract
Fruit flies are important pests of major economic significance in most of the temperate, subtropical and tropical countries. The Larvae of most species attack soft fruit, including many commercial hosts. B. zonata is an active insect pest throughout the year in Egypt and it has four to six considerable economically generations per year.
The control of fruit flies is mainly dependent on the use of insecticides. The control measures for fruit flies adopted mainly on contact conventional insecticides that cause destructive effects on the environment, human health and wild life and biological control agents. There are several ways to solve the problems involved with chemical insecticides. One solution is to use chemical insecticides that are relatively safe or have low mammalian toxicity such as pyrethroids. Another solution is using insecticides of natural origin that are eco-friendly and safer than traditional ones such as natural oils. To decrease the hazards of synthetic insecticides on human health and the environment, chemical insecticides at low concentrations can be combined with other safe control agents as natural oils.
Factors like time of adult emergence and longevity, female size and number of eggs produced, the length of oviposition period, and the time needed for larval development may all be influenced by insecticides used. Also, the biochemical actions on the same pest were studied.
6.1. Toxicological Studies
Three insecticides (malathion, Lambda-cyhalothrin and spinosad), two natural oils (lemon-grass and sesame) and mixtures of pesticides and oils were used as toxic agents for adult of B. zonata.
6.1.1. Estimation of the toxicity of malathion, plant oils and their mixtures against the peach fruit fly
For male of peach fruit fly, LC50 values for malathion with lemon-grass oil, (0.008%) was the most potent compound. Also, female of peach fruit flies, LC50 value for females of malathion with lemon-grass were 0.007%. The combination between different values of lethal concentrations of malathion with lemon-grass and sesame plant oils revealed a potential action against males and females of B. zonata.
6.1.2. Estimation the toxicity of lambda-cyhalothrin, plant oils and their mixtures against the peach fruit fly
Lambda-cyhalothrin surpassed the other tested compound against males and females of B. zonata at LC25 and LC50 recording the lowest values of 0.0008 and 0.002, respectively.
6.1.3. Estimation the toxicity of spinosad plant oils and their mixtures against the peach fruit fly
For males of the peach fruit fly, the LC50 values for spinosad, lemon-grass oil, sesame oil, mixtures of spinosad + lemon-grass oil and spinosad + sesame oil were 0.7, 0.30, 0.4, 0.2 and 0.07 %, while for females they were 0.6, 0.3, 0.6, 0.07 and 0.17%; respectively. Mixing spinosad with lemon-grass or sesame oils showed lower LC50 values.
6.2. Biological Studies
6.2.1. Biological activity of malathion, natural oils and their mixture on adult of B. zonata
The obtained data statistically clarified that there was no remarkable effect on the pre-oviposition period for all tested compounds compared to control, except malathion with sesame which significantly increased the pre-oviposition period. The tested compounds significantly reduced the oviposition period compared the untreated individuals. Tested compounds differently and significantly reduced the fecundity, the percentages of egg hatchability, pupation and emergence percentages compared to control. Statistical analysis of variance proved that the longevity of males and females of B. zonata significantly decreased for all tested compounds compared to control.
6.2.2. Biological activity of lambda-cyhalothrin, natural oils and their mixtures on adult of B. zonata
The results of the study showed that there was no significantly differences between the pre-oviposition period for lambda-cyhalothrin, sesame and lemon-grass and control, but lambda-cyhalothrin with sesame and lambda-cyhalothrin with lemon-grass significantly increased the pre-ovipostion period compared to control, whereas, all tested compounds significantly reduced the oviposition period compared to control. Both lambda-cyhalothrin and lemon-grass significantly increased the post oviposition period, whereas sesame, lambda-cyhalothrin with sesame or lemon-grass shortened this period. Comparing the untreated individuals with the tested compounds, a significant reduction in the fecundity, the percentages of egg hatchability, pupation and emergence was observed. The longevity of males and females of B. zonata significantly decreased by all tested compounds compared to control.
6.2.3. Biological activity of spinosad, natural oils and their mixtures on adult of B. zonata
The pre-oviposition period of individuals treated with spinosad alone and spinosad mixed with either sesame or lemon-grass insignificantly showed the highest periods. Females treated with lemon-grass only significantly showed the highest post-oviposition period. Also, significant decreases were investigated in case of the mean number of eggs laid by treated females. For hatchability of laid eggs, significant decrement took place after treatment with the tested compounds. The formed larvae hardly succeeded to pupate compared to control and that was insignificantly different with lemon-grass oil treatment alone. Percentage of adult emergence greatly and significantly decreased when mixing spinosad with lemon-grass oil or with sesame oil compared to the tested compounds separately. Males and females significantly showed reduced longevity periods in all tested compounds compared to control.
6.3. Biological Activity of the Tested Compounds and Mixtures with Lemon-grass and Sesame on F1 Progeny of B. zonata
6.3.1. Biological activity of malathion, natural oils and their mixtures against F1 progeny of B. zonata
The tested compounds insignificantly affected the pre-oviposition period of B. zonata. But the oviposition period was significantly influenced. All tested compounds differently and significantly shortened the period of oviposition. In case of post-oviposition period the all tested compounds showed longer periods than control, whereas, the all tested compounds significantly reduced the fecundity, % hatchability, pupation and emergence. Comparing the untreated individuals with all tested compounds different reduction in the longevity of both males and females were observed.
6.3.2. Biological activity of lambda-cyhalothrin, natural oils and their mixtures against F1 progeny of B. zonata
Lambda-cyhalothrin significantly reduced the pre-oviposition period which insignificantly differed with that of lemon-grass, sesame and lambda-cyhalothrin with lemon-grass. The untreated females of F1 progeny and that of lambda-cyhalothrin with sesame insignificantly showed the highest period. Tested compounds significantly reduced the oviposition period. On the other hand, all tested compounds significantly increased the post oviposition period. The untreated individuals significantly recorded the highest values of fecundity. The percentages of egg hatchability, pupation and emergence of the treated individuals significantly decreased. Also, the male and female longevities significantly decreased compared to control.
6.3.3. Biological activity of spinosad, natural oils and their mixtures against F1 progeny of B. zonata
All tested biological aspects of F1 progeny of B. zonata showed the same trend of the parent progeny. The untreated individuals significantly recorded the highest values, except with the post-oviposition period.
The differences of pre-oviposition period between treatments were statistically insignificant. The oviposition period of treated individuals was significantly lower than that of the untreated ones. All tested compounds reduced the fecundity, % hatchability, % pupation and % emergence compared to control. Also, males and females longevities significantly decreased compared to control.
6.4. Fraction protein pattern of adult abdomen tissues after treatment with the insecticides, oils and their mixtures
In all tested compounds on adults (males and females) of B. zonata the results showed that protein pattern differ not only between different treatments but also at different time intervals in same treatment, as the study showed absence of some protein bands, reduction in the intensity of others and appearance of a new bands.