معصومه ثمره فکری

Bemisia tabaci is one of the most important pests of crops. In this study, the preference of free and non-free hosts, the growth period, and the percentage of pre-maturation mortality of this pest on certain cucumber cultivars under greenhouse conditions were carried out in a completely randomized block design. the results showed that the effect of different cucumber cultivars on total insect attraction and free spawning rate was significant. The highest and lowest total number of insects per unit leaf area was recorded at 10.97 and 7.18 on Y353 and Brilliant, respectively. additionally, the highest and lowest number of eggs per unit leaf area was observed at 56.29 and 28.13 on Y353 and Brilliant, respectively. The results showed that there was a significant difference among tomato cultivars in terms of non-free spawning preference at a 1% level. the highest and lowest number of eggs per unit leaf area was observed on Y353 (43.77) and Brilliant (23.82), respectively. The effect of the host cultivar had a significant impact on both the length of the growth period and the percentage of mortality before reaching maturity. the highest growth period (32.86 days) and the highest percentage of mortality (60.20 days) were recorded on the Brilliant cultivar and the lowest growth period (26.74 days) and the lowest percentage of mortality (43.63 days) were recorded on the Y353 cultivar. Therefore, Brilliant is less suitable than other cultivars for controlling B. tabaci, making it an appropriate choice for pest management strategies to minimize damage.

Bemisia tabaci (Gennadius.) (Homoptera: Aleyrodidae) is one of the most important pests of crops, greenhouses, and ornamental plants. In this study, the sub-lethal effect of Teucrium polium(Lamark)(Lamiales:Lamiaceae) on parameters of life table age- bisexual stage of B. tabaci (Gennadius.) was evaluated on the sensitive cultivar ( Ergon) and resistant cultivar (Cal-JN3) of Lycopersicon esculentum . 2-4 leaves seedlings of L. esculentum from sensitive and resistant cultivar were submerged in methanol extract of T. polium and water+ methanol (control) and were placed in cup cages. 30 imago insects of the same age were released in the cup cage and after 24 hours the imago insects were omitted and the eggs whose age was less than 24 hours were kept. The sexuality of the imago insects exiting these eggs exposed to the contaminated plant was determined and the rate of spawning of the female insect was daily recorded to the last day of its life. The experiment was investigated in a glass greenhouse and 27+ 2  temperature and relative moisture of 50 ± 5 and in lighting conditions of 16 hours of light and 8 hours of darkness. The results showed that there is a significant difference in the one percent level. The intrinsic value of population increase, reproduction gross rate, and reproduction net rate on the sensitive cultivar (Ergon) and resistant cultivar (cal-JN3) of the L. esculentum treated with T. polium L. was acquired 0.069, 31/43 and 11.03 and 0.061, 18.51 and 6.66 respectively.  Generally, in this study conjugate application of resistant plant cultivar and extract caused more loss and considerable reduction of the intrinsic rate of population increase comparing other treatments which subsequently lower the population of B. tabaci. So, the combined application of using resistant cultivar and the herbal extract is considerable in the population control of this pest.

Saw toothed grain beetle (Oryzaephilus surinamensis) is one of the serious and destructive foods pests.it is a polyphagous insect, which feeds from variety of products. Nowadays, using plant-based combination instead of artificial insecticides usage, especially in storage pests, has received much attention. In the present research,  the effects of repllency and Oviposition deterrence of extract (concentration:240,320,400,480,560 (µl/l air ) )and powder (mix of 2 grams powder with 2 grams of wheat seeds) leaves and flowers of Acroptilon repence and Sophora aculeopoides was evaluated on final instar larvae and adult insects . The experiments were done in a dark room with the temperature range of 30±5°C and 70-75% relative humidity. The output results indicate that the extract and powder of the studied plants are effective on the repllency and oviposition deterrence of saw toothed grain beetle, and the effects of the extract and powder of A.repence on the desired parameters are greater than the S. aculeopoides of the expression. The results showed that the percentage of repllency and oviposition deterrence in the extracts of both plants were increased with concentration-increment. Intense insects reacted more in comparison with larvae against extracts and powders. The information obtained from this study could be helped the storekeeper for storing the warehouse products in a long-term and controlling the damages of saw toothed grain beetle.

Cotton whitefly, Bemisia tabaci (Gennadius) is one of the most important pests of agronomic in greenhouse’s crops and ornamental plants. In this study, the effect of sublethal dose of Fumria parviflora (Lamark) (Papaverales: Fumariaceae) extract on the age-stage, two-sex life table parameters of B. tabaci was evaluated. While insect was reared on sensitive (Ergon) and resistant (Cal j n3) tomato cultivars. A total of 30 adult insects of the same age were released into glass cage and the adults were removed after 24 hours. All less than 24 hours old eggs remained and the fecundity were recorded daily until the end of the last day of life. Experiments were done in greenhouse under controlled condition; 27 ± 2°C , 50 ± 5 %rh and 16 h light/8 h dark. Results showed lower intrinsic rate of increase, gross reproductive rate and net reproductive rate of pest on resistant varieties Cal j n3 with amount of 0.062 d-1, 37.2 egg/individual and 10.1 egg/individual respectively, than insects reared on susceptible cultivar, Eregon which were treated with Fumaria extract with amount of 0.071 d-1, 39.85 egg/individual and 13.82 egg/individual respectively. The intrinsic rate of increase reduction in control treatment of Cal j n3 cultivar showed the effect of resistant cultivars on pest population dynamic. Although extract of fumaria application increased a crash of population on both cultivars, coeffect of resistancy and herbal pesticide application showed a better result. The highest intrinsic rate of increase was observed in control and ergon treatments with 0.1 d-1 and the lowest rate was recorded on F. parviflora Cal j n3 (0.06 d-1) ones. Therefore, usage of resistant varieties beside the herbal pesticides application showe deeply effect on this pest population density and is very important in its IPM strategy.

In this research، the effect methanolic extracts of Fumaria parviflora، Teucrium polium and pesticide pymetrozine was assessed on the lethality and general esterase activity of adult Bemisia Tabaci (Genn.) at 27±2°C، 50±5 % RH and 16:8 (L: D) photoperiod. In bioassay experiments tomato plants of resistant (cal-j-n3) and susceptible (Ergon) cultivars with 2-4 leaves were immersed in different concentrations of plant extracts، and mortality was calculated 72 h after treatment. This study was conducted by using a randomized complete design with three replications. For each treatment، distilled water and methanol were used as control. To evaluate effects of treatments on esterase activity، seedling with 2-4 leaves are being thread with extracts and insecticides (LC25). The results showed that، the LC50 of the extract of F. parviflora، T. polium and pesticides pymetrozine for adults reared on susceptible and resistant cultivars، were، 17. 26، 93. 88، 0. 026 and 13. 26، 68. 36، 0. 019 (g/lit)، respectively. Sublethal effect of extracts and pesticides was significant on esterase enzyme activity compared to control. The amount of esterase enzymes، for control and adults treated with the extract of F. parviflora، T. Polium، pesticides pymetrozine on susceptible cultivar، were 0. 0161، 0. 0086، 0. 009، 0. 0038، respectively and for resistant cultivar were 0. 027، 0. 0068، 0. 0097، 0. 0043 (μg alpha naphtyl acetat per minute/mg protein) respectively. Thus the rate of toxicity of F. parviflora T. polium extracts، and pesticide pymetrozine was more insects that reared on resistant variety in comparison of adults that reared on susceptible variety. Also، pesticide Pymetrozine showed the most toxicity rate. The toxicity rate of F. Parviflora was recorded more than T. polium. Esterase enzyme activity was more in treated insects on resistant varieties compared to susceptible varieties. According to the results usage of resistant varieties with plant extract or pesticide can be a good strategy against whitefly in IPM programs.

Five separate Experiments were carried out to estimate food preference of sawtoothed on different stored grains. All experiments were conducted on a 1×1m2 wooden board at dark with temperature 25 ± 5°C and Relative Humidity (RH) 75-90%. The same age and naive male an female beetles were released on the center of each board. Eight intact and powdered kernels including wheat, rice, sultana, walnut, pistachio, almond, bean and lentile were separatedly compared at two series. Results of both treatments showed higher preference of saw-toothed to wheat than other foods (P