Two-spotted spider mite, Tetranychus urticae Koch, is one of the important pests of bean, which can cause severe damages on it. Silicon is one of the micronutrient elements, as its spray on the leaves can decrease the...Two-spotted spider mite, Tetranychus urticae Koch, is one of the important pests of bean, which can cause severe damages on it. Silicon is one of the micronutrient elements, as its spray on the leaves can decrease the population of the pest. In this research, the impact of four different doses of Si (0, 1, 1/5, 2 ppm) was investigated on biological and population growth parameters of T. urticae. The experiments were carried out in Petri dishes in an incubator at 25°C ± 2°C, 65% ± 5% RH and 16 L: 8 D. The duration of developmental stage was significantly affected by Si dose. The longest immature period, the shortest longevity of females and the shortest oviposition period were obtained at 2 ppm. In addition, Si dose significantly affected population growth parameters of the mite. The intrinsic rate of natural increase (rm) of the mite ranged from 0.246 to 0.215 day which lowest and the highest values were at 2 ppm and control plants, respectively. The lowest net reproductive rate (R0) and finite rate of increase (λ) of the mite and the highest value of mean generation time (T) and doubling time (DT) were estimated at 2 ppm. The results of this peruse represented that 2 ppm had better potential for decreasing the population of the two-spotted spider mite, and it can be used in the mite integrated pest management programs.展开更多
The volatile constituents of the essential oil of Hymenocrater longiflorus Benth. growing wild in Kurdistan-Iran were investigated using the GC and GC/MS techniques. Fifteen compounds, representing twenty (97.03%) of ...The volatile constituents of the essential oil of Hymenocrater longiflorus Benth. growing wild in Kurdistan-Iran were investigated using the GC and GC/MS techniques. Fifteen compounds, representing twenty (97.03%) of the total oil were identified. The main components were: α- Pinene (22.47%), β-Caryophyllene (18.05%), β- Eudesmol (14.92%), α-Copaene (9.84%), γ-Elemene (6.79%), δ-Cadine-ne (6.13%), (–)Bornyl acetate (5.61%), α-Amorphene (3.84%), α-Fen- chyl acetate (2.35%) and β-Pinene (2.07%). Some of the physicochemical properties like the logarithm of calculated Octanol-Water partitioning coefficients (log Kow), total biodegradation and (TBd in mol/h and gr./h), water solubility (Sw, mg.L-1 at 25oC) and median lethal concentration 50 (LC50) were calculated for the 15 com- ponents of Hymenocrater longiflorus Benth.展开更多
文摘Two-spotted spider mite, Tetranychus urticae Koch, is one of the important pests of bean, which can cause severe damages on it. Silicon is one of the micronutrient elements, as its spray on the leaves can decrease the population of the pest. In this research, the impact of four different doses of Si (0, 1, 1/5, 2 ppm) was investigated on biological and population growth parameters of T. urticae. The experiments were carried out in Petri dishes in an incubator at 25°C ± 2°C, 65% ± 5% RH and 16 L: 8 D. The duration of developmental stage was significantly affected by Si dose. The longest immature period, the shortest longevity of females and the shortest oviposition period were obtained at 2 ppm. In addition, Si dose significantly affected population growth parameters of the mite. The intrinsic rate of natural increase (rm) of the mite ranged from 0.246 to 0.215 day which lowest and the highest values were at 2 ppm and control plants, respectively. The lowest net reproductive rate (R0) and finite rate of increase (λ) of the mite and the highest value of mean generation time (T) and doubling time (DT) were estimated at 2 ppm. The results of this peruse represented that 2 ppm had better potential for decreasing the population of the two-spotted spider mite, and it can be used in the mite integrated pest management programs.
文摘The volatile constituents of the essential oil of Hymenocrater longiflorus Benth. growing wild in Kurdistan-Iran were investigated using the GC and GC/MS techniques. Fifteen compounds, representing twenty (97.03%) of the total oil were identified. The main components were: α- Pinene (22.47%), β-Caryophyllene (18.05%), β- Eudesmol (14.92%), α-Copaene (9.84%), γ-Elemene (6.79%), δ-Cadine-ne (6.13%), (–)Bornyl acetate (5.61%), α-Amorphene (3.84%), α-Fen- chyl acetate (2.35%) and β-Pinene (2.07%). Some of the physicochemical properties like the logarithm of calculated Octanol-Water partitioning coefficients (log Kow), total biodegradation and (TBd in mol/h and gr./h), water solubility (Sw, mg.L-1 at 25oC) and median lethal concentration 50 (LC50) were calculated for the 15 com- ponents of Hymenocrater longiflorus Benth.
