p. namvar

Many aphids attack cucumbers in the greenhouse and reduce their quality and quantity. Various varieties of greenhouse aphid species, particularly Aphis gossypii Glover, are responsible for considerable damage to cucurbits and vegetables, including cucumbers, tomatoes, watermelons, melons, etc. In addition, these insects can transmit many plant viruses from infected plants to healthy ones.

This study was conducted in the cucumber greenhouses of the three provinces of Sistan and Baluchestan, western Azerbaijan, and southern Kerman by a randomized complete block design with five treatments and four replicates. The efficiency of Emamectin benzoate 4.8% + Acetamiprid 6.4% EC at a ratio of 1.5/1000 and 2 /100 was compared with Flonicamid (Teppeki 50 WG) at a ratio of 0.25 /100, Primicarb (DF 50%) at a ratio of 0.7 /1000, Dichlorvos (EC 50%) at a ratio of 0.5 /1000, and the control (water spraying). The sampling was done one day before and 3, 7, and 14 days after treatment. The Henderson-Tilton formula was used to calculate the efficiency of the pesticides. And the means were compared by Tukey's test and SAS software. In the second part of this study, to measure the pesticide residues, 11 samples (one sample from each both different doses were collected three times: 3, 6, 8, 13, and 15 days after spraying, while one sample was taken as a control with no treatment) were collected in West Azerbaijan Province and transferred to the Pesticide Residues Reference Laboratory in the Pesticide Research Department. The samples were crushed, homogenized, and prepared. The organic phase obtained in the process was used for the cleanup stage and then centrifuged. Furthermore, residual pesticide content was identified and quantified by optimizing the operating conditions of the LC-MS/MS instrument. Finally, a comparison of the calculated levels with the national MRLs was made to determine the level of the toxin residues present in the product.

The results showed the following on the third day after spraying:The concentration of Emamctin benzoate + Acetamiprid treatment in Sistan and Baluchestan province was 2/1000 (77. 30 ± 4.6%). The concentration of Imamctin Benzoate + Acetamiprid insecticides in the Western Azerbaijan province was 2/1000 and 1.5/1000, and the concentration of Flonicamid was 95.02 ± 2.35, 94.42 ± 1.07, and 91.68 ± 3.65% respectively. Subsequently, Emamectin benzoate + Acetamiprid in the concentration of 2/1000 with an efficiency of 100% performed better than the others. The examination of the pesticide residues in the insecticide-treated cucumbers showed that the residues of Emamectin benzoate in all the samples sent after harvest were so low that LC-MS/MS was not able to detect it both quantitatively and qualitatively. Although the Acetamipride residue was 0.058 and 0.063 mg/kg respectively in both treatments on the third day after spraying, the level was below the permissible limit. Moreover, it was not detectable from the sixth day after spraying.

Tomato leaf miner, Tuta absoluta Meyrick, is a pest which entered Iran in 2010; it was spread rapidly in many areas including Jiroft, in the southern Kerman province. The predatory bug, Nesidiocoris tenuis Reuter (Hempitera, Miridae) is an effective biocontrol agent against T. absoluta in tomato greenhouses. To evaluate the efficiency of N. tenuis in controlling T. absoluta, the predator was released in five treatments including: one pair of adult predator per plant, 6 fourth stage nymphs per plant in the same time with the artificial pest release, one pair of adult predator per plant and 6 fourth stage nymphs per plant one week before artificial pest release and control (no predator). The experiments were done in a completely randomized block design with 3 replications. Evaluation was done on 40 and 70 days after the artificial pest release on 20 plants per plot which had been selected randomly. The results showed that the two treatments of predator release before pest release were significantly better than the others in reducing the number of larvae (5 ± 1.52, 5.1 ± 1.01 on 40th day and 2 ± 0.58, 4 ± 0.58 on 70th day), mines (11.4 ± 2.96, 10.7 ± 2.2 on the 40th day and 4.67 ± 0.67, 6.7 ± 0.88 on 70th day) and the percent of the damaged fruit (4.7 ± 1.45 and 7.3 ± 1.21), as well as increasing the predator established on plants (3.6 ± 0.14, 3.1 ± 0.07 on the 40th day and 5.8 ± 0.2, 4.6 ± 0.24 on the 70th day). Moreover, these two mentioned treatments had no significant difference with the others in regard to the symptoms of N. tenuis damage in plants, especially in the final evaluation; so they could be recommended for use in commercial greenhouses.

Tomato leaf miner, Tuta absoluta Meyrick (Lep.: Gelechiidae) is a invasive pest for country since 2010 and spread rapidly in different regions including Jiroft. Regarding the increased area of tomato cultivation under greenhouses conditions in this region, the unknown status of pest and its high potential for damage, the study of population fluctuation and determining the best area of the plant for sampling of pre-adult stages is very important to make reliable management decisions. In this study in a tomato cultivated greenhouse, leaves were weekly sampled to check various stages of insect growth including eggs, larvae, and leaf mines. The results showed that the insect activity observed from the middle of growing season and population density gradually increased to its peak in April and May. During this period of time, it reproduces 4-5 generations. The highest number of insect eggs was found on the upper half of the plants and mainly in the lower surface of the leaves. In addition, it was revealed that the sampling of leaf mines was more accurate than counting different developmental stages in estimating the population density of this pest. Based on Correlation test, it was found that there is a positive correlation between the changes in the number of leaf mines and density of larval population in the upper half of the plant. Accordingly, the population density of larvae can be estimated only by sampling the leaves in this section and counting the number of leaf mines.

In this study, susceptibility of the first three larval stages of Spodoptera exigua to Bacillus thuringiensis was investigated. To determine the LC50 values for each larval instar, 6 different logarithmic concentrations of Bacillus thuringiensis were used. A control was also included in each of the bioassays. The value of LC50 for 1st instar larvae, that had been treated one to four hours after hatching, was 311.617 ppm. For the 2nd and third instars, the larvae values of LC50 were 1356.95 and 2708.27 ppm, respectively. It was clear that larval susceptibility to Bacillus thuringiensis decreased with age. In order to enhance the Bacillus thuringiensis efficiency to control Spodoptera exigua under field conditions, Bacillus thuringiensis should be applied at egg hatch peaks.