الفهرس 
Chemical used as InsecticidesOnly 14 pages are availabe for public view
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Abstract
The tomato leafminer, T. absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a major pest of fresh tomatoes, both in greenhouse and open field crops, and is one of the most serious polyphagous insect pests. T. absoluta can develop on cultivated and wild Solanaceae. However, its preferred host plant is tomato. It can also occur on potato, eggplant, sweet pepper, pepino, and tobacco. In the absence of cultivated Solanaceae, this pest can attack a wide range of weeds of the same family. Recently in 2009, the tomato leafminer, Tuta absoluta was recognized in Egypt. Larvae can completely destroy the tomato canopy by mining leaves, stems and buds and burrowing tunnels in the fruits, causing the UN marketability of fresh tomatoes and yield losses up to 100%. To avoid damage should be early detection of the pest by using pheromone traps to identify the presence of pest and attract males and control. Control of tomato leafminer infestations is difficult, because of the endophytic habit of larvae, which are protected in the leaf mesophyl or inside fruits.Using pesticides it won, t affect the pest because there was no contact,the pest need a pesticide that transform between the leaves know as ”translaminar effect”. This investigation was carried out on tomato plants in the Agricultural Experimental Farm of the Faculty of Agriculture, Qena, South Valley University, Egypt, during the two successive seasons, 2012 and 2013.
The present study aimd to control of tomato leaf miner T. absoluta
The results in our investigation can be summarized as follows:
1. Evaluate the influence of sex pheromone and trap colour on the attractiveness of male T. absoluta moth in open field tomato crops.
Field experiments were conducted to determine the attractive action of different colors (yellow and blue) of Tuta absoluta moths and to asses the influence of trap color on their capture moths in sex pheromone with water traps. Data showed fluctuations in the number of males caught per trap/ week during the period of experiment. The mean number catch of T. absoluta moths per trap/observation were (430.7, and 826.7) for trap colors (yellow, and blue), respectively. In the 1st seasons, while in the 2nd season were 71.2 and 126.5). Color preference of T. absoluta moths was indicated by the numbers caught on the water traps. Significant differences were found in the mean capture of moths among two colors of water traps. Blue water traps captured significantly more moths than the yellow traps.
IV.1. Bioassays for evaluation of the relative toxicity of certain insecticides against the 3rd instars larvae of tomato leafminer, T. absoluta under laboratory conditions
Eight insecticides representing different classes or types with different modes of action were chosen to evaluate their toxicity against the 3rd instar larvae of field strain of T. absoluta. The tested insecticides in the present study were chlorpyrifose, methomyl, lambada cyhalothrine, imidacolpyrid, abamectin, chlorfenapyr, chlorantraniliprole, and emamectin benzoate. The residual film bioassay method was used to evaluate the toxicity of the tested insecticides. .
Data clearly indicate that the order of efficiency of the tested insecticides were the same at both LC50 and LC90 levels. The tested insecticides could be in arranged descendingly as follows: abamectin, chlorfenapyr, chlorantraniliprole, methomyl, emamectin benzoate, chlorpyrifos, lambada cyhalothrin, and imidacloprid. Based on the LC50 values the results indicated that the abamectin was the most toxic insecticide (LC50 =48.02 mg/L) followed by chlorfenapyr (154.64), chlorantraniliprole (314.73), methomyl (539.99), emamectin benzoate (566.36), chlorpyrifos (899.71), cyhalothrin (1663.90), and imidacloprid (2115.70). The difference in toxicity between the most toxic insecticide (Abamectin) and the least toxic one (imidacloprid) was up to 44.06 fold. The corresponding LC90values were 678.76, 1884.63, 3540.34, 4797.71, 6545.56, 12028.37, 34962.43, and 62008.05. It is clear that abamectin was the most toxic compound whereas imidacloprid was the least toxic one, and the remained compounds were in between.
3. Field efficacy of certain insecticides against the tomato leafminer, T. absoluta on tomato plants during 2012 and 2013 seasons.
3.1. Mean number and infestation percent of the infested tomato leaves by T. absoluta
Field experiments were conducted to evaluate eghit insecticides, i.e. chloropyriphose, methomyl, lambada cyhalothrine, imidacolpyrid, abamectin, chlorfenapyr, chlorantraniliprole, and emamectin benzoate. against T. absoluta on tomato plants during 2012 and 2013 seasons. The tested insecticides were applied two times at two weeks intervals; in two seasons.
Data show the larvicidal action of the eight tested insecticides. It is obvious that number of living larvae/120 leaves was greatly decreased after insecticide application. Also, data indicated that all the tested insecticides had significantly affected the insect population (larval instar) from infested leaves. Abamectin was the more effective than other tested insecticides. The insecticides are arranged according to their potency as follow; abamectin, chlorantraniliprole, chlorfenapyr, methomyl, emamectin benzoate, cyhalothrin, imidaclopride, and chlorpyrifos. The average percentages reductions of infestation were 85.37, 83.25, 81.87, 77.37, 73.83, 73.62, 64.25, and 64.80 % in the first season. While, in the second season were 84.90, 86.39, 78.55, 75.00, 81.00, 70.40, 36.30, and 36.50 %. It’s obvious that from data abamectin was the most effective insecticides and chlorpyrifos was the least effective in the first season, while in the second season were chlorantraniliprole was the most effective insecticides and imidaclopride was the least effective. Chlorfenapyr, methomyl, emamectin benzoate, and cyhalothrin were intermediate position. The tested insecticides showed a variable adverse effect on T. absoluta, this may be due to the differences between the chemical structure, mode of action of the used compound, and the prevailing environmental conditions during individual studies.
Iv.3.2. Mean number and infestation percent of the infested tomato fruits by T. absoluta
In this experiment data showed that the insecticidal treatments decreased the mean number of the infested fruits/ 120 fruits on tomato plants, and percentage of infestation. In both seasons, the percentage reduction of infestation increased in the 1st week, while decreased in the 2nd week, this may be due to rate of decomposition of pesticides from plants. The average percentages reduction of infestation for abamectin, chlorfenapyr, chlorantraniliprole, methomyl, emamectin benzoate, chlorpyrifos, cyhalothrin, and imidaclopride on the tomato fruits were 49.62, 47.34, 50.76, 41.28, 38.02, 34.00, 32.56, and 35.37 %, respectively in the first season. While in the second season, the corresponding values were 58.07, 56.06, 60.12, 48.27, 49.00, 43.67, 42.00, and 46.67 %. It’s obvious that from data chlorantraniliprole was the most effective insecticides and lambda cyhalothrin was the least effective. This study reavaled that there is a slight difference in the efficiency of pesticides tested between leaves and fruits due to the amount of pesticides that are located on the surface plant.
It concluded that the results obtained from the field trails showed the same trend with laboratory studied. Also, the results indicated that all the tested insecticides had significantly affected the insect population and the average percentages reduction of infestation with T. absoluta in tomato plants in open field. The average percentages reduction of infestation had affected by tested insecticides and part of plant (leafs & fruits).Finally it is should be applied an integrated pest control program by pheromone with colour traps to monintoring and mass trapping for this pest recommended by using abamectin, chlorfenapyr, and chlorantraniliprole in controlling this insect according