A New Trend for Controlling Tomato LeafMiner , Tuta absoluta ( Meyrick )

The tomato leafminer, Tuta absoluta causing a huge economic problem in Egypt. The effects of Agree 50% WG, Avaunt 15% EC, Excellent 1.9% EC, Titan, Castor aqueous extract, K.Z oil, and Alboleum oil against the tomato leaf- miner, T. absoluta (Meyrick) were evaluated. Avaunt 15% EC is succeeded in T. absoluta management since it is initially reduced of the infestation were 80.42 and 78.29, respectively. Meanwhile, the total mean of reduction after 1, 3, 10, and 15 days were 79.20, and 79.26 respectively, for the 1st  and 2nd  spray. While the initial reduction of Excellent 1.9% EC, Agree 50% WG, Castor aqueous extract, Titan, K.Z oil, and Alboleum oil were 80.68, 80.38, 79.70, 71.62, 72.44, and 70.68, respectively for 1st  spray. Furthermore, the initial reduction of Excellent 1.9% EC, Agree 50% WG, Castor aqueous extract, Titan, K.Z oil, and Alboleum oil were 80.76, 77.23, 77.30, 72.58, 70.00, and 69.98 for 2nd  spray, respectively. The total mean of reduction for Avaunt 15% EC, Excellent 1.9% EC, Agree 50% WG, Castor aqueous extract, Titan, K.Z oil, and Alboleum oil were 79.20, 74.71, 74.59, 72.72, 70.35, 69.15, and 64.96 for 1st  spray, respectively. Although, the total mean of reduction for Avaunt 15% EC, Excellent 1.9% EC, Agree 50% WG, Castor aqueous extract, Titan, K.Z oil, and Alboleum oil was 79.26, 74.73, 73.88, 73.40, 68.49, 67.47, and 62.27 for 2nd  spray, respectively


INTRODUCTION
Tuta absoluta, the tomato leafminer, invade a huge number of crops. it has grown into one of the cosmopolitan pests for tomato (Larrain, 1986) Lietti, et al., 2005. Egypt and other countries in Africa were recorded as a spot of this pest infestation (Bloem & Spaltenstein, 2011). Larvae of T. absoluta attack tomato plants' parts, both yield and fruit quality can be significantly diminished by direct feeding of larvae, and consequently by pathogens arriving at tunnels causing fruit rot. Seriously compromised tomato fruits made them lose their commercial value (Robredo-Junco & CardenosoHerrero, 2008).
Several research have studied the potential of B. thuringiensis in regulating T. absoluta González-Cabrera et al., 2011;Ladurner et al., 2011;Sellami et al., 2015). Beauveria bassiana was reported for its efficacy towards immature stages of T. absoluta (Gregorio et al., 2009;Urbaneja et al., 2009). Considering insufficient define biological agents are operating against tomato leafminer and to conquer the dilemma of resistance that may occur against biological agents. The use of ecofriendly and efficiently biodegradable plant products with natural insecticidal activity has elevate in recent years. Plant materials with insecticidal properties have been used to control insects all over the world for long time, because of their low toxicity to animal and humans. (Belmain et al., 2001). Using of minerals' oils and Bacillus thuringiensis on Tuta absoluta was poorly studied on tomato fields in southern Egypt. Therefore, the present investigation may contribute to add some information about safe control of the pest, which in twin may help in achieving a successful control program for checking of the ravages of pests in tomato fields. The present work was undertaken to evaluate the efficacy of some pesticides and certain alternatives against the tomato leafminer, T. absoluta on tomato under field and laboratory conditions.

Insecticidal Test Against T. absoluta Larvae Under Field Conditions:
The present work was carried out to evaluate the toxicity of Avaunt 15% EC, Excellent 1.9% EC, Agree 50% WG, Titan, aqueous extraction Castor (Ricinus communis), and two minerals oils (K.Z oil and Alboleum oil) at recommended concentrations, table (1) against T. absoluta associated with tomato plants during the summer cultivations of 2016/2017 and 2017/2018 seasons at the Experimental Farm, Faculty of Agriculture, South Valley University, Qena, Egypt. The Experimental design was a complete randomized block design with three replicates, and each replicate was 7m. long by 6m. wide (1/100 Fd). Tomato cultivars (Super Jakal) were cultivated in October.
The pesticides and their alternatives were sprayed using a knapsack sprayer with one nozzle, as foliar treatment, diluted with distilled water at the rate of 200-liter spray liquid per feddan. Two sprays were applied. The control plots were sprayed with distilled water. The experiment was established with randomized complete block design (RCBD) was performed with each treatment replicated 3 times. The control treatment was sprayed with deionized water as untreated. Avoid sampling circumference plants to ignore border effects. Leaves collecting always executed in the morning. Samples were randomly collected at cross A new Trend for Controlling Tomato Leaf-Miner, Tuta absoluta (Meyrick) 263 direction per each plot at weekly intervals. Live and dead larvae were counted. The total number of larvae and mines was counted under the microscope. To evaluate the effect of pesticides on T. absoluta, samples of 10 leaves were randomly picked from every single replicate. Sampled leaves representing upper, middle, and lower leaves of the chosen shoots, then placed in paper bags. All samples were transferred to the laboratory for inspection. Inspection of infestation was carried out 1 hour before the application, 1,3,7,10, and 15 days after spraying.
Percent reduction in infestation was calculated using (Henderson & Tilton, 1955). % Reduction Percentage =100 {1-(Cb/Ca x Ta/Tb)} Where: T a = Aveg. % of infestation in treatment plots after spray. C b = Aveg. % of infestation in check plots before spray. T b = Aveg. % of infestation in treatment plots before spray. C a = Aveg. % of infestation in check plots after spray.

Bioassay:
Bioassay was conducted in the (Plan Protection department Lab, Faculty of Agriculture, South Valley University).Ten larvae were placed in 120 mm Petri dishes. Aqueous dispersions of commercial insecticide formulations were used. Tomato leaf dip bioassay (Cahill, M. et al., 2009). Dipping tomato leaves for 5 sec. in aqueous solutions of recommended insecticide concentrations while the untreated leaves were dipped in distilled water. Each treatment was replicated 6 times and mortality was recorded after 24, 48, and 72 hours.

Statistical Analysis:
Results for the bioassay were analyzed with SAS 9.2 using Duncan test at α= 0.05. Mortality rates of larvae were submitted to ANOVA test. For the Field experiment collected data were analyzed statistically for analysis of variance to determine the significant difference among the treatments. Reduction percent was calculated according to the percent reduction in infestation (Henderson & Tilton, 1955), using LdP line software, (Bakr, 2005).

Insecticidal Test Against T. absoluta Larvae Under Field Conditions:
The effects of Agree 50% WG, Avaunt 15% EC, Excellent 1.9% EC, Titan, Castor aqueous extract, K.Z oil, and Alboleum oil against the tomato leaf-miner, T. absoluta (Meyrick) were evaluated. The present data stated that tested insecticides could be arranged in descending order according to their potency as follows: Avaunt 15% EC > Excellent 1.9% EC > Agree 50% WG > Castor aqueous extract > Titan > K.Z oil > Alboleum oil According to the recommendation of the Egyptian ministry of agriculture for using insecticides and their alternatives in controlling pests, effective materials should give initial effect not less 264 than 70% reduction and residual effect not less than 40% reduction (Anonymous, 2001). Based on this recommendation, the result in Tables 2 and 4 showed that the recommended rate of Avaunt 15% EC is succeeded in managing T. absoluta since its initial reduction of the infestation were 80.42 and 78.29, respectively. Meanwhile, the total mean of reduction after one hour, 1, 3,5,7,10 and 15 days were 79.20 and 79.26 respectively, for the 1 st and 2 nd spray. while, the initial reduction of Excellent  (Dağlı et al., 2012) stated that Avaunt 15% EC has a high impact on the larvae and the mortality was 100% this means that this Pest developed resistance towards this insecticide and we should do more investigations to find more effective compounds. The total mean of reduction for Avaunt 15% EC, Excellent 1.9% EC, Agree 50% WG, Castor aqueous extract, Titan, K.Z oil, and Alboleum oil were 79.20, 74.71, 74.59, 72.72, 70.35, 69.15, and 64.96 for 1 st spray, respectively. While The total mean of reduction for Avaunt 15% EC, Excellent 1.9% EC, Agree 50% WG, Castor aqueous extract, Titan, K.Z oil, and Alboleum oil were 79.26, 74.73, 73.88, 73.40,68.49, 67.47, and 62.27 for 2 nd spray, respectively. Data in, table (2) showed that reduction percent of infestation by T. absoluta due to the application of tested pesticides and their alternatives indicated that Excellent 1.9% EC was the most effective compound in reducing the infestation. It exhibited that the initial reduction was 80.68 %. On the other hand, Castor aqueous extract exhibited 79.70 and 77.30 % in its initial effects of both sprays, respectively. These results agreed with those of (Chowański et al., 2014) stated that Insecticides extracted from plants have a harmful impact on the environment and create a low risk of insecticide resistance than synthetic insecticides; therefore, they can be proposed as a safe tool for controlling this pest.
Several problems have resulted from the intensive use of conventional pesticides for pest control such as insect resistance; outbreaks of pest population; destruction of non-pest species; environmental pollution and human health hazards. Nanomaterials and Plant extractions and mineral oils such as KZ oil and Alboleum oil could be considered promising alternatives to insecticides for use against T. absoluta and they are currently being marketed for that purpose in liquid and dust forms. These findings agreed with those reported by many investigators (Maurya & Malik, 2016). Also, mineral oil might play an important role as effective alternatives (Helmy et al., 2012).
Data represented in tables (2 & 4) showed the initial reduction of K.Z oil and Alboleum oil were 72.44% and 70.68% for 1 st spray and 70.00 % and 71.27 % for 2 nd spray, respectively, and all of the used compounds are above 70% reduction. From these results, it should be suggested to employ some effective alternatives such as K.Z oil and Alboleum oil in controlling T. absoluta incompatible program with chemical insecticides instead of conventional insecticides. The initial deposit of Avaunt 15% EC, Excellent 1.9% EC, and Agree 50% WG were 80.42, 80.68, and 80.38 % for 1 st spray. While it was 78.29, 80.67, and 77.23 % for the 2 nd spray, respectively. This illustrates that the traditional insecticides exhibited outstanding potency in reducing infestation by T. absoluta as compared with the oils. However, this is not enough to recommend using these insecticides widely in controlling this pest species. It is better to suggest using alternatives of pesticides in controlling T. absoluta incompatible program with other controlling agents instead of the traditional insecticides alone.
Data stated in tables (2,3,4 & 5) indicated that all the used insecticides had affected the insect population. The most effective insecticide was Avaunt 15% EC while the Alboleum oil was the least effective one. While the mean percent of reduction for one hour, 1, 3,5,7,10, and 15 days intervals were 72.72 and 73.40 % for both sprays, respectively. Data clearly show that there is a wide range in the response of the insects to the action of the seven tested compounds. It is noticeable that the percent reduction of infestation depended on the type of used compounds.
The present study recommends that Avaunt 15% EC insecticide was better than Excellent 1.9% EC, Agree 50% WG insecticides for managing T. absoluta, while Castor aqueous extract was better than Titan, K.Z oil and Alboleum oil and it should use as an alternative candidate. So that, Castor aqueous extract, K.Z oil, and Alboleum oil should be considered in integrated pest management (IPM) programs of T. absoluta.    Chemical methods have been the most common control method used by growers. However, the extensive usage of pesticides has caused negative effects, such as the selection of resistance biotypes, causing growers to increase dosages or repeated application for a short time that obtained less satisfactory results over time (Siqueira et al., 2000). The newer insecticide classes have provided good activity against this pest (Irac, 2010;Shahini et al., 2021). A rotation of compounds with different modes of action usually provides a sustainable and effective approach to managing insecticide resistance (Irac, 2009).

Bioassay:
Selected compounds were tested at lab conditions 26 o C ±2 against T. absoluta 3 rd instar larvae according to the recommended rates. Table (6) and fig (1) showed that Agree 50% WG was the most effective compound on the larvae for the 1 st day of treatments with a 4.5 mean number of individuals. However, Titan was the least effective one 8.8. For the 2 nd day, Avaunt 15% EC has the highest impact on larvae with 1.8 this result agreed with (Shalaby et al., 2012) and Aqueous extract of Castor was the least effective compound 7.0 comparing with control. After the 3 rd day Agree 50% WG was the most powerful compound for controlling T. absoluta larvae with 0.5 mean number of individuals. Moreover, aqueous extract of Castor was the same as 2 nd day 6.7. From these results we recommend using the insecticide list that used in this bioassay, Agree 50% WG for controlling such a pest because of its ability to maintaining killing larvae within days as mentioned by (Khidr et al., 2013;Balzan &Moonen, 2012 andHafsi et al., 2012) that Bacillus thuringiensis was the most effective in larval reduction percentage.