m. forouzan

Cabbage aphid, Brevicoryne brassicae L., is one of the most important pests of cruciferous crops worldwide. In the present study, the lethal (LC50) and sublethal (LC25) effects of Clothianidin and summer oil were investigated on biological properties and population growth rate parameters of cabbage aphid under greenhouse conditions. The leaf dipping method containing aphid adults was used for bioassays. The life table data were analyzed based on the age-stage, two-sex life table theory. Results indicated that Clothianidin affected the population growth rate of aphids by prolongation of the pre-adult stages, decreasing survival rate, adult longevity, and reproduction in comparison to summer oil. The lowest fecundity rate (14.14 nymphs per female) was recorded in Clothianidin treatment. The lowest and highest intrinsic rate of increase (r) was observed in Clothianidin (0.2123 day-1) and control (0.3636 day-1), respectively. The results also demonstrated that population growth of the cabbage aphid in different treatments was exactly in consistent with the estimated population growth parameters. For example, aphids treated with Clothianidin, had slower growth rate and, thereby prolonged mean generation time (T). The overall results demonstrated that Clothianidin could be considered as an effective insecticide in the management of cabbage aphid.

Two-spotted spider mite, Tetranychus urticae Koch, is a serious pest for many agricultural crops. Use of effective pesticides and release of biological control agents are common methods in integrated pest management programs. In the present research, effect of different concentrations of Ebron Speed® and Kane Mite® on mortality of two-spotted spider mite and number of predatory mites Phytoseiulus persimilis and Amblyseius swirskii were investigated in laboratory conditions. LC50 values of Ebron speed® and Kane Mite® were calculated for egg stage of this pest as 252.47 and 1564.10 ppm, and for protonymph stage, as 207.17 and 1120.00 ppm, respectively. Therefore, results of this study showed that egg is more resistant stage than protonymph stage. Time required for 50% lethality (LT50) of Ebron Speed® and Kane Mite® on protonymph stage as 22.984 and 25.097 hours were calculated, respectively. The highest amount of feeding on eggs and protonymph stages infected with acaricides after 48 hours from time of spraying in predator mite P. persimilis was observed. According to results, use of Ebron Speed® and release of P. persimilis predator after 48 hours are recommended in the integrated pest management programs of this pest.

Aphis gossypii Glover is a polyphagous pest that infects a wide range of host plants in temperate, tropical and subtropical regions. Therefore, it has a great ability to maintain its population in different environmental conditions. Quantitative and qualitative damages of this pest are through feeding on plant sap, transmission of viral diseases, reduction of photosynthesis and secretion of honeydew. Various factors such as excessive use of chemical insecticides, the destruction of natural enemies and the emergence of resistant pest populations have increased the population of aphids and turned it into a damaging pest. However, the most common method of controlling aphids, despite its negative effects, is usage of chemical insecticides. The high potential of this pest in resistance to chemical compounds requires investigating and using of newer insecticides with different modes of action. Insect reproductive parameters as an ecological and indicator tools, can indicate the behavior and physiology of different types of pests after pesticides using. Studies have also been conducted on the effect of sub lethal concentrations of insecticides on behavior, biological characteristics and growth of insect population, which provides a more realistic estimate of the effect of insecticides on pests and natural enemies. Therefore, in this study, the lethal and sub lethal effects of the new combined insecticide Emamectin benzoate 4.8% + Acetamiprid 6.4% which has contact and oral function, was evaluated on the aphids biological and population growth parameters in greenhouse conditions.

The colony of cotton aphid used in the experiment was obtained from pinto beans fields in Urmia, West Azerbaijan (Iran), during September 2021. The aphid population was reared on pinto beans var. Khomein in plastic pots (12 × 6 cm) under controlled greenhouse conditions (21 ± 1°C, 50% ± 10% RH, and a photoperiod of 16: 8 [L: D] h). The LC50 concentration of Emamectin benzoate + Acetamiprid for cotton aphid adults was 23.84 ppm 24 hours after treatment. The values of LC10, LC20 and LC30 were estimated at 1.76, 4.31 and 8.22 ppm, respectively. The insecticide spraying method on leaves containing aphids was used in bioassay and life table studies against adults of aphid insects. The age stage, two-sex life table method was used to analyze the collected data. We used the bootstrap technique with 100,000 iterations to estimate the variance and standard errors of the biological and population parameters and used Sigma Plot software to draw graphs. The growth of the pest population in a period of 60 days was done with Timing-MsChart software.

According to the results, the adult lifespan/longevity was significantly different from the control by LC20 and LC30 concentrations. The shortest lifespan of adult aphid in LC30 treatment was recorded as 5.90 days. Fertility and the duration of Nymphal period were significantly reduced in sub lethal concentrations of the insecticide compared to the control. The highest value of pre adult period in LC30 concentration was recorded 8.88 days and the lowest value in control treatment was 5.06 days. All biological table parameters of cotton aphid treated with sub-lethal concentrations were significantly affected by the insecticide compared to the control. The highest value of intrinsic rate of increase (r) was 0.39 per day in control. The net reproductive rate (R0) decreased from 28.37 nymphs per female/generation in control to 6.90 in LC30 concentration. The lowest value of finite rate of increase (λ) was observed in LC30 concentration, which was 1.18 per day. The gross reproductive rate (GRR) in sub lethal concentrations was significantly lower than the control. The highest and lowest values of mean generation time (T) were estimated in LC30 (11.28 days) and control (9.11 days), respectively.

Based on the findings of the present study, considering the necessity of using chemical insecticides for aphid management, and the significant effect of this pesticide on the aphid Emamectin benzoate + Acetamiprid insecticide can be used to control and reduce population of cotton aphids and it can be a suitable alternative to old insecticides. In order to confirm the greenhouse results, it is necessary to conduct similar experiments in field conditions, and conduct laboratory and field studies on the effects of this compound on the natural enemies of A. gossypii especially bees and coccinellids.

Brevicoryne brassicae is one of the most serious cabbage pests in the world. This pest feeds on the leaves, mostly on the host plant's middle leaves. Despite having many natural enemies, aphids are not entirely controlled by natural enemies due to their rapid reproduction. Applying chemical insecticides is one of the essential methods used to control aphids; using one pesticide to control several pests can reduce the costs and frequency of spraying. In this study, the lethal and sub-lethal effects (LC25) of matrine insecticide with a contact and stomach function on the cabbage aphid, were evaluated under laboratory conditions.

The dipping method was used in bioassay and life table studies against adults of aphid insects. The LC50 value of matrine insecticide for adults of cabbage aphid was 83.33 μl/ml after 24 hours, and LC25 concentration (30.11 ml/ml) was used to estimate the sub-lethal effects of matrine on the biological parameters of the cabbage aphid. Experiments were performed on the acephala variety of cabbage. One common method of investigating insecticides' non-lethal effects is demographic toxicology, which uses life table and growth population parameters to evaluate toxicity.

According to the results, the female lifespan/longevity and fertility affected by sub-lethal concentration were significantly reduced compared to the control (distilled water and citowett). The mean oviposition period of adult aphids decreased from 8.92 days in control to 3.79 days in LC25 concentration of the insecticide. The present study's data also showed that the sublethal concentration also affected the offspring of treated cabbage aphids. Accordingly, the sublethal concentration of matrine reduced the net reproductive rate (R0) from 23.96 nymphs per female in each generation in the control treatment to 3.26 nymphs in LC25. The intrinsic rate of increase (r) in sublethal concentration was recorded as 0.36 (day-1) and in control as 0.1 (day-1). Other parameters, such as finite rate of increase (l) and gross reproductive rate (GRR), were also significantly lower than the control. The mean generation time (T) of treatment affected by LC25 concentration of matrine increased compared to the control treatment.

Results of the current research in laboratory conditions showed that this insecticide has significant lethal and sublethal effects on the cabbage aphid. Therefore, matrine, as an herbal insecticide, can be considered in the management programs of cabbage aphids.

Cucumber, Cucumis sativus L. is one the most important economic vegetables crop cultivated in Iran and many countries of the world. The cotton-melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is one of the most destructive polyphagous pests of Cucurbitaceae plants in greenhouses and open fields. A. gossypii can cause severe damage in commercial fields. The honeydew that aphid excretes decreases the photosynthetic activity of plants and contaminates fruit, resulting in severely reduced quality. Moreover, A. gossypii can transmit more than 80 type of viral diseases that can cause substantially greater losses than the damage from direct feeding of the insect. The focus of the control methods against this pest in our country is the use of insecticides. Additionally, A. gossypii has developed different levels of resistance to many insecticides. Agricultural adjuvants can improve the efficacy of pesticides and can be effective in reduction of pesticides use. In the current research, the effects of two adjuvants (Scorch and Torpedo п) on efficiency of imidacloprid (SC35%) and flonicamid (WG50%) to control this aphid were investigated on cucumber in greenhouse. These two insecticides have systemic property doing their job after leaf penetration. It is known that the leaf penetration step is very determinative for systemic pesticides. Besides, Scorch and Torpedo п are multi-functional adjuvant, showing penetration, wetting, adhesion and spreading properties.

The project was performed based on a completely randomized design with 15 treatments and 3 replicates. The efficacy in the sampling units was recorded at 1, 3, 7 and 14 days after treatment. The treatments were: 1) imidacloprid (recommended dose); 2) imidacloprid+Scorch; 3) imidacloprid+Torpedo п; 4) imidacloprid (10% reduction of dosage)+Scorch; 5) imidacloprid (20% reduction of dosage)+Scorch; 6) imidacloprid (10% reduction of dosage)+Torpedo п; 7) imidacloprid (20% reduction of dosage)+Torpedo п. Flonicamid was replaced by imidacloprid in the treatments 8 to 14. The control treatment (No. 15) was sprayed by water only. The efficacy was calculated using the Henderson and Tilton formula. Statistical analysis was performed using the SAS software (ver. 9.1). One row was considered as the distance between the experimental units. Two rows on either side of the greenhouse were also considered as margins.

The combine analysis of variance showed that interaction of treatment × place was not significant, meaning that the experimental treatments had the same respond in different locations. Therefore, the data were statistically analyzed based on this, without considering the locations (Urmia and Karaj). The results showed that both adjuvants were able to improve the efficacy of imidacloprid and flonicamid, as it was confirmed at all times after spraying. For example, three days after spraying, the efficacy of imidacloprid alone was estimated at 81.47%, while "imidacloprid + Torpedo" and "imidacloprid + Scorch" were estimated at 92.60% at 93.43%, respectively. Similarly, seven days after spraying flonicamid alone showed 87% efficiency, whereas the treatment of "flonicamid+Torpedo" and "flonicamid+Scorch" exhibited 94.34% and 95.31%, respectively. When Torpedo п was used in combination of reduced doses of imidacloprid, the efficacy was severely reduced. Thus, the addition of Torpedo п is not recommended with reduced doses of imidacloprid. Instead, adding the Scorch when reducing the imidacloprid dosage, the efficacy was remained as high. For example, three days after spraying, "Imidacloprid with 10% dose reduction + Scorch" and "Imidacloprid with 20% dose reduction + Scorch" treatments were 93.65% and 94.23% efficacy, respectively. Besides, by reducing the flonicamid dosage and adding both adjuvant, the efficiency was as high as to the treatment using the recommended dosage. For example, 14 days after spraying, flonicamid with 10% dose reduction + Scorch and flonicamid with 20% dose reduction+ Scorch showed 93.94% and 93.48% efficacy, respectively. Our results can be important from both economic and environmental point of view, as the obtained results indicated that imidacloprid and flonicamid dosage can be reduced by 20%. However, it should be keep in mind that other factors, such as the price of adjuvants, are involved in their practical and field use by farmers, which should be taken into account.

The turnip moth, Agrotis segetum is considered as one of the most important pests of sugar beet. The larvae of this pest feed on sugar beet crown from the second age onwards and cut off the root from the stem causing seedling dryness. This research was conducted during 2013-15 in West Azerbaijan and Lorestan provinces. The efficacy of Bt Semisolid bait was compared with an organophosphate pesticide, Dursban in West Azarbaijan and Lorestan provinces. Four treatments including Dursban (Chlorpyrifos) EC 40.8% 2 l/ha, Bt bait (5l Bt (Biolop) + 50l water + 100 kg wheat bran)/ha, Bt (Biolop) Spray (3 ml/l), Semisolid Bt bait (100 Kg/ha) were used on the turnip moth in sugar beet fields in a randomized complete block design with four replications, in two periods of 7 and 10 day after emergence. In the province of West Azerbaijan, results of combined analysis of variance showed that the treatment of premature Bt semisolid bait with 4.3% damage had thehighest rate of damage reduction and was significantly better than other treatments. In the Lorestan province, the efficacy of Semisolid Bt bait and Dursban was better than the other treatments.