Nature and Science

An experiment was conducted toward the development of integrated control program for the tomato leafminer Tuta absoluta in the summer growing season of 2012 at Manwat village, Giza governorate. An integrated pest management (IPM) program which consisted of mass-trapping T. absoluta males in red plastic basin traps at a density of 8 traps / feddan, biweekly application of voliam flexi 40 % WG (20 % Thiamethoxam+ 20 % chlorantaniliprole) and Dan top 50 % WG (Clothianidin) in sequence during vegetative stage and weekly application of Dipel DF 6.4 % W G(Bacillus thuringiensis) during fruiting stage was compared with mass trapping only and farmers practice in which farmers sprayed several insecticides at their own discretion. The results showed that mean percent fruit damage was lower in the field treated with pheromone baited water traps only (44.33 %) than that in the farmers field (41.93 %), both being significantly higher than that in the field treated with such traps in combination with insecticide application. Therefore T. absoluta sex pheromone appears to be a valuable component in the integrated management of T. absoluta. [Taha, A. M.; A. F. E. Afsah and Fargalla, F. H. Evaluation of the effect of integrated control of tomato leafminer Tuta absoluta with sex pheromone and insecticides. Nat Sci 2013;11(7):26-29]. (ISSN: 1545-0740). http://www.sciencepub.net/nature. 5


Introduction
Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) commonly known as tomato leafminer is an important pest that also feeds on other host plants from the Solanaceae family ( Vargas, 1970). It was first recorded in Western Egypt in late 2009 (Temerak, 1199). Young larvae can mine leaves, stems, shoots, flowers and developing fruits. later instars can attack mature fruits (Vargas, 1970). In the absence of control strategies, larval feeding can result in up to 100 % crop losses (Apablaza, 1992 andEstay, 2000). Although various control measures have been practiced to reduce the damage caused by the tomato leafminer, insecticide applications remain the main control method (Siqueria et al., 2001). The internal living and feeding habits of the larvae and its ability to produce several broods each year make it necessary for farmers to apply insecticide every 4 -5 days / season with minimum and maximum numbers of sprays 8 to 25 sprays respectively (Temerak,2011). Intensive use of insecticides results in environmental damage, build up of insecticides residues on tomato fruits (Walgenbach et al., 1991), destruction of natural enemy populations (Campbell et. al., 1991), and rapid development of insecticide resistance. In Argentina, Tuta absoluta was reported to be resistance to deltamethrin, and abamectin (lietti et al., 2005). Resistance to cartap, abamectin,permethrin and methamidophos (Siqueira et. al., 2000) and acephate and deltamethrin (Branco et. al., 2001) has been reported in Brazil. The devastation of the tomato leafminer coupled with the fact that it has the capacity to develop resistance very rapidly to any control measure used singly has made this pest the focus of IPM research in many countries of the world. Among components of IPM programs, the use of sex pheromonebaited traps has given promising results against the tomato leafminer in Spain (Robredo-Juncoard cardensoso-Herrero, 2008) and Argentina (Botto, 1999) There have been few efforts on using of synthetic sex pheromone of tomato leafminer in Egypt. In this paper the effectiveness of mass-trapping only and mass-trapping together with insecticide applications in controlling the pest are reported.

Materials and Methods
The experimental area of two feddans (feddan = 4200 m 2 ) located at Manwat village in Giza governorate (Egypt) was subdivided into three fields ( Figure 1). Field 1 (½ feddan) was treated with insecticides together with pheromone-bated water basin traps (IPM program) ( Table 1). Field 2(½ feddan) used pheromone-bated water basin traps only. Field 1 and field 2 were separated from each other by about one feddan cabbage. Field 3 (one feddan) separated from other tomato fields by about 2 feddans lettuce was treated with pesticides commonly used by tomato farmers (farmers program) ( Table 1) each experimental field was divided into three replicates. Thirty-day-old seedlings of tomato (lycopersicon esculentum Mill Cv. Supper strain B) were transplanted on 10 February 2012. Tillage, fertilizer application and irrigation followed the recommended cultivation practices. In pheromone treated fields four red plastic basin water traps (40 cm. dimeter, 21 cm. high) with water containing detergent (0.2 %), red traps appeared to be the most attractive color for monitoring T. absoluta moths (Taha et al., 2012), were baited with a pheromone lure obtained from Chemtica, Heredia, Costa Rica) containing 0.5 mg of the synthetic pheromone (E3, Z8, Z11tetradecatrienyl acetate).The traps were placed 30 cm above the ground for trapping male moths throughout the period from transplanting to harvest. Traps were visited weekly to remove moths and replenish water and detergent with pheromone Lures renewed every four weeks. The tomato leafminer infestation in each treatment was determined weekly by recording the numbers of eggs, live larvae and mines in a random sample of 60 leaflets from each treatment (20 leaflets / replicate).The fruits damaged caused by Tuta absoluta larvae were assessed at weekly intervals for 3 weeks starting May 17. At each date 60 plants / treatment (20plants / replicate) selected randomly were inspected carefully and the number of healthy and damaged fruits were recorded to calculate the percentage of damaged fruits. Data from treatments were subjected to analyzed and the difference between means was tested for significant at 5 % level by F. test according to Fisher (1944), Sendoecor (1956) and Sendecor and Cochron (1972).

Results
The population level of the pest was slightly higher for the first 3 weeks as can be seen from the number of eggs, larvae and mines found per leaflet. The mean number of eggs was significantly lower in fields treated with pheromone-baited traps together Dirt road with insecticide applications (IPM) (0.39 / leaflet) and field treated with pheromone-baited traps only (0.33 / leaflet) than in the field treated with insecticides (farmers field)(0.59 / leaflet) ( Table 2). Similarly the mean number of surviving larvae was significantly lower in the field treated with pheromone-baited traps together with insecticide applications (0.09/ leaflet) and in the field treated with pheromone-baited traps only (0.12/ leaflet) than in the farmer ُ ُ s field (0.24/leaflet). (Table 2). * * * ** * = Significant different (0.05). ** = Highly significant different (0.01) Means followed by the same letters are not significantly different at 0.05 level of probability.
The mean number of mined leaflets was vary significantly among different treatment methods. The mean number of mined leaflets was significantly lower in IPM field (0.19/ leaflet) than in the pheromone -baited traps field (0.45/leaflet) or in the farmer ُ ُ s field (0.67/leaflet). Nevertheless level of mined leaflets in the farmer's field was significantly higher than that of the field treated with pheromone. baited traps only ( Table 2). Mean percent damaged fruit by T. absoluta larvae was significantly higher in the farmer's field (39.16 % damaged fruits) than in IPM field (4.65 % damaged fruit) but not significantly different than pheromone-baited traps field (37.44 % damaged fruits) (Fig. 2) b a a.

Discussion
The tomato leafminer which have a short generation time and high biotic potential are at increased risk of developing resistance to insecticide use. Resistance to organophosphate and pyrathyroid insecticides has been reported in Chile (Salazer & Araya, 1994. Previous reports demonstrated the feasibility of using the tomato leafminer synthetic pheromone in monitoring (Balizan and Moonen, 2012) and mass trapping (Robredo-Juncoard cardensoso-Herrero, 2008). However, to our knowledge, this is the first report demonstrating the efficacy of the integrated application of pheromonebaited traps and insecticides to suppress the tomato leafminer infestation.
Our results indicated that mass trapping of male moths together with selected insecticide applications (IPM program) was effective in reducing damage below the economically acceptable limit (1 -5 % damage fruits) reported for fresh-market and processing tomato (Gravena, 1991). Moreover, the IPM program used a lower total number of sprays (11) than the corresponding regular farmer , s practice sprays (16). In the farmer , s field, the tomato leafminer larval population densities still remained at high larval population densities during flowering and fruiting stages and caused damage to fruits above the economical acceptable level in spite of multiple insecticide applications. One reason may be that the farmer used non selective and effective insecticides, the other reason may be that the chemical insecticide was difficult for farmers to spray on the pest uniformly, particularly as vegetable grow large.
In the filed treated with pheromone bated traps only, the patterns of fruit damage did not differ significantly from that in the farmer , s field. Among the many possible reasons for the failure of mass trapping in the control of T. absoluta are that the trapping system employed did not capture all the available males and migration of gravid females from other places to the pheromone-treated area Therefore, the sex pheromone of the tomato leafminer T. absoluta appears to be a valuable component in IPM programs against this pest. Integrating sex pheromone-baited water traps with alternative weekly applications using insecticides from different made of action groups offers even better control.