رقیه کریم زاده

The stem and bulb nematode Ditylenchus dipsaci is one of the most important plant-parasitic nematodes with a worldwide distribution, causing damage mainly in temperate regions. Onion, garlic and alfalfa are its main hosts. The use of nematode-free seeds and plant propagation materials, crop rotation, resistant cultivars and chemical nematicides are common methods of its management. Due to the side effects of nematicides on human health and the environment, the use of safe, cost-effective alternative methods are necessary. In this study, the nematicidal effects of the essential oils of mountain thyme, oregano, clove, sage and savory as well as the metabolites of the fungus Scytalidium sp. were studied in comparison to metam sodium under laboratory conditions. To prepare the nematode population, nematodes were extracted from naturally infected garlic from the Gogan region of East Azarbaijan province, reared on carrot discs and incubated at 18 ± 1°C for 60 days. The effects of plant essential oils, fungal metabolites and metam sodium were investigated in bioassays with four replicates, and nematode mortality was recorded after 24 and 48 hours. After a probit analysis, the LC50 and LC90 values were calculated for each of the compounds tested. After 24 hours, the LC50 values for the essential oils clove, oregano, marzeh and thyme were 1748, 769.2, 1662 and 4913 ppm, respectively, and for the fungal metabolite and metam sodium were 207.6 and 6.7 ppm, respectively. Gas chromatography with a mass spectrometer (GC-MS) and a DB5 column was used to identify the components of the essential plant oils and the metabolites, the results of which are presented here. Based on the LC50 values, the compounds tested caused mortality and population decline of D. dipsaci at relatively low concentrations, with the exception of sage-flower.

The parasitic wasps Ooencyrtus telenomicida and Trissolcus grandis are among the most common biocontrol agents of the common sunn pest (CSP), Eurygaster integriceps. The Ooencyrtus spp. act as facultative hyperparasitoids of CSP eggs, which may earlier have parasitized by Scelionidae. The preference and choice of these wasps among hosts of different quality (recently deposited eggs, 2-, and 4d-old eggs, as well as recently parasitized CSP eggs by T. grandis, 3-, 7-, and 10 d-old parasitized eggs) was studied. The results indicated that, unexpectedly, parasitism rate was the highest in 4d-old eggs, while the wasps significantly avoided 10d-old parasitized eggs. The functional response experiments were carried out with the same set of hosts. The 72h-old inexperienced fertile females were confined individually with different host densities for 6h. The response of the wasp to all kinds of the host was a type III response. No response to 7d-old parasitized eggs was evident (non-significant parameters). Depending on the treatment, the highest parasitism rate occurred at densities 5 to 9 which was between 25.7 and 46.5%. The handling time and maximum attack rate ranged between 0.61 - 1.83 h and 3.27-9.85 host eggs respectively. The maximim parasitism rates was observed in the 10d-old parasitized eggs, newly deposited eggs and 4d-old eggs. The results of the functional response and host preference experiments were not confirming, and therefore more studies are still required to reveal the impact of host quality on the parasitoid.

This study was conducted to determine distribution pattern and related parameters of spotted alfalfa aphid, Therioaphis maculata (Buckten), pea aphid, Acyrthosiphon pisum (Harris) and two coccinellid species (Coccinella septempunctata L. and Hippodamia variegata Goeze) in six alfalfa fields during two growing seasons, 2016 and 2017. Weekly sampling was started when alfalfa plants reached 10 cm in height and continued until harvest. Each field was divided into 20m×20m plots. Two samples per plot per sampling time were randomly taken using a 1 × 1 m quadrat, to count adult coccinellids. Twenty alfalfa stems (longer than 10cm) per plot were randomly cut and shaken eight times on a white pan to record the aphids' density. The aphids that fell into the pan were counted and recorded. The ratio of variance to mean, as well as Taylor’s power law (TPL) and Iwao’s patchiness index (IPI), were used to determine the spatial distribution patterns of the insects. The variance exceeded the mean on all sampling dates, which may imply an aggregative distribution. Aggregation was also confirmed by using regression coefficient of both TPL (parameter b) and coefficient of IPI (β), which both were significantly above unity. Correlation between aphid counts and those of the coccinellids indicated that there was a positive but weak relationship between predator and prey densities in the fields, although a weak correlation may imply that factors other than prey accessibility contribute to the spatial distribution of the predators. Using different statistical methods provides useful information about the spatial distribution and dispersal pattern of aphids and natural enemies in alfalfa fields, and this information can be used in the biological control of pests.

Codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae) is the key insect pest of apple orchards in Iran. This study was conducted in the main apple-growing regions of East Azarbaijan Province to generate potential habitat suitability maps of C. pomonella using MaxEnt modeling and to determine the importance of vegetation index in improving the accuracy of these models. Field surveys for collecting the occurrence data of codling moth were conducted during three growing seasons, 2017 - 2019. The activity of codling moth adult males was monitored using delta-shaped traps baited with female sex pheromone. Fifteen environmental variables were considered as potential predictors for estimating codling moth distribution. These variables were categorized into topographic, climatic, and remote sensing variables. A MaxEnt modeling algorithm was used to predict the distribution of codling moth. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC). By using the topographic, climatic, and topographic+climatic variables, the AUC values were 0.840, 0.951, and 0.938, respectively. The model including normalized difference vegetation index (NDVI) had the highest AUC value (0.99), which strongly supports model predictive power and indicates the importance of vegetation index in codling moth distribution modeling. NDVI was the most contributed variable in the model followed by precipitation of September, slope, minimum temperature of May, and mean temperature of April. The distribution map obtained in MaxEnt provides an important tool for identifying potential risk zones of codling moth. This map can assist managers in forecasting and planning control measures and therefore, effective management of current infestations of codling moth.

In this study, the possibility of chemical control against 1st instar larvae of leopard moth Zeuzera pyrina  using peak flight time of adults, was assessed in walnut orchards of East Azarbaijan province. For this purpose, three areas were chosen in walnut orchards of Oskou and Azarshahr Counties. Pheromone traps were used to determine the peak flight time of leopard moth. The trees were sprayed with chlorpyrifos, imidacloprid, chlorpyrifos + imidacloprid, chlorpyrifos + indoxacarb, chlorpyrifos + fenvalerate and chlorpyrifos + cypermethrin, 12 days to two weeks after the peak of flight. Unsprayed trees were considered as controls. For damage assessment at the end of the growing season, eight to 16 trees were chosen from the control and treatment plots based on the plot area. Eight samples were taken per tree stratified as four main directions (N, E, S, and W) and two canopy levels (upper and lower half of the tree crown). Each sample was a 60 cm branch terminal. The number of larval tunnels in each sample was counted and recorded separately. Chlorpyrifos + cypermethrin had the greatest effect in reducing the number of larval tunnels (90.75 %), and imidacloprid had the lowest effect (37.5 %). Chlorpyrifos, chlorpyrifos + fenvalerate, chlorpyrifos + indoxacarb and chlorpyrifos + imidacloprid caused 51.11 %, 87.65 %, 83.33%, and 79.44 % reduction in infestation compared to control, respectively. All chemical treatments had significant difference with control at 0.05 probability level. The results of this study showed that in high populations of the pest, the use of chemical insecticide can be recommended at the peak of the emergence of first instar larvae to reduce the damage.

The growing demand for broadband services for moving devices led to the development of ESIM (Earth Station In Motion) technology. These services can be used in cars, trains, air and sea ships. The International Telecommunication Union (ITU) and many regional and national telecommunications regulators are developing standards and regulations that, when complied with by ESIM, minimize such interference. At WRC2015, the frequency band of 20.2-19.7 GHz and 29.5-30 GHz assigned to ESIM. In addition, at WRC2019, the frequency band was extended to 17.7-19.7 GHz and 27.5-29.5 GHz and the regulatory and interference considerations were raised by various countries. In WRC2023, these issues will be addressed, as well as the use of ESIM in FSS Non-GEO satellite systems in the 17.7-19.7 GHz and 27.5-29.5 GHz. Several services were already using part or all of the frequency band allocated to ESIM (GEO or Non-GEO). Service providers, operators, and regulators have largely taken into account interference and licensing processes over the years. In this research, an brief introduction of ESIM has been given. After a brief presentation on how the studies and analyzes have been done in order to extract the requirements for controlling ESIM interference in ITU documents and meetings, the initial scenarios for analysis the interference are stated. In the following, the technology of Network Control and Monitoring Center (NCMC) along with monitoring stations, monitors of radio-space spectrum, Geoloction system and the challenges of their implementation are briefly described. Finally, due to the need to provide ESIM service in the near future as well as the development of related technologies, the challenges in this area were summarized.

This study aimed to model spatial distribution of alfalfa plant bug Adelphocoris lineolatus in six alfalfa fields during two growing seasons. Weekly sampling was started early in the spring and continued until cutting the hay. The plant bugs were sampled using six to eight 180° sweeps per 400 m2 grid and bugs captured by sweep net were counted. The data were analyzed using regression methods, dispersion indices and geostatistical analysis. According to the results, the variance to means ratio, dispersion indices (ID), David -Moore index (IDM), Lloyd’s index (x*) and Green's Index ( ) were greater than one, indicating the aggregated distribution. Regression statistics also showed that in all studied fields in the first and second year, distribution of the pest was aggregated and random, respectively. Due to the high coefficients of determination and the low standard error values of the regression coefficients, Taylor’s model was more efficient than Iowa’s model. The results of geostatistics confirmed the results of regression methods and distribution coefficients; and K index was less than 0.8 for 18 out of 20 datasets, which indicates the aggregated distribution. These results can be used in sampling and pest management programs of alfalfa plant bug.

Among biological control agents of common sunn pest (CSP), Eurygaster integriceps Puton, egg parasitoids of family Encyrtidae have little been studied. The Encyrtidae can play different roles in a cereal agroecosystem depending on level which it will occupy in food chain. It means it can appear either as primary parasitoid of CSP or hyperparasitoid of the platygastrids. Although at first glance hyperparasitism seems an undesirable property, but it depends mainly on preference of the parasitoid. If parasitoid prefer unparasitized hosts, may enhance control level. In this study, host preference of Ooencyrtus fecundus Ferriere & Voegele (Hym.: Encyrtidae) was evaluated in pairwise experiments between three kinds of hosts (fresh host eggs, 6d-old host eggs and eggs parasitized by Trissolcus grandis (Thomson) (Hym.: Platygastridae) (8d-old)). The results revealed that the parasitoid definitely prefer the fresh eggs and the preference is not affected by relative densities of the hosts. When no suitable host was available, handling was declined considerably and negative effect of fetal development was stronger than previous parasitism. It seems that the wasp partly saves its reproductive energy for subsequent fortunes in circumstances that the favorable host is unavailable.

Compatibility of Beauveria bassiana (Balsamo) with hexaflumuron, chromafenozide, chlorfluazuron, phosalone, garlic extract and pepper extract was studied at the laboratory condition. In details, 75, 150, 300 and 500 µl of the insecticides and extracts were incorporated into 100 ml of liquefied potato dextrose agar (PDA) culture medium. Seven, 15, 17 and 19 days after treatment, diameter of the colonies was measured and compared in the treatments and control. In the second part of the study, the effects of B. bassiana, chromafenozide, chlorfluazuron, phosalone, garlic extract, pepper extract, hexaflumuron, azadirachtin and B. bassiana + garlic extract, were determined on alfalfa leaf weevil Hypera postica (Gyllenhal), pea aphid Acyrthosiphon pisum Harrisand the two species of coccinellids including Hyppodamia variegata (Goeze) and Coccinella undecimpunctata L. under field conditions. Experiments were conducted using randomized complete block design with four replicates. A sampling was conducted a day before treatments and three samplings were conducted 1, 3 and 7 days after treatments. The Efficacy of treatments was calculated using Henderson-Tilton's formula. The results indicated that garlic and pepper extracts were compatible with B. bassiana and those can be used simultaneously in pest management programs. Three days after treatment, efficiency of garlic and pepper extracts, hexaflumuron and B. bassiana + garlic extract was significantly higher on young larvae of H. postica than other treatments and those can be considered in this pest management programs. Chromafenozide, azadirachtin and hexaflumuron had > 50% efficiency on pea aphid population. Among these insecticides, hexaflumuron may be recommended for pea aphid control due to its relatively low effects on the lady beetles.

Use of pesticides as an important part of integrated pest management programs has principal role in control of tomato leafminer, Tuta absoluta (Meyrick). Therefore, evaluating the efficacy of insecticides and introducing new effective compounds are important for management of this pest. Eggs and 2nd instar larvae of tomato leafminer are the main stages exposed to insecticide sprayings. This study was conducted to determine the susceptibility of eggs and 2nd instar larvae of T. absoluta to five insecticides. LC50 values obtained for spinosad, chlorantraniliprole, indoxacarb, abamectin, and zeta-cypermethrin for 2nd instar larvae were 0.08, 0.09, 10.8, 0.29 and 232.2 mg ai/L respectively. The eggs were treated with LC50s of these insecticides for 2nd instar larvae to assess their ovi-larvicidal effects. Mortality of the egg/neonates in chlorantraniliprole, spinosad, indoxacarb, abamectin, zeta-cypermethrin treatments and control were 88.8, 76.8, 58.1, 35, 50.5 and 14.6 %, respectively. The results revealed that spinosadand chlorantraniliprole had strong ovicidal and larvicidal activities; and if perform equally well in large scale greenhouse and field conditions, they may be considered in T. absoluta management programs.

Understanding the spatial dynamics of insect distributions provides useful information about their ecological requirements and can also be used in site-specific pest management programs. Interactions between prey and predator are spatially and temporally dynamic and can be affected by several factors. In this study, geostatistics was used to characterize the spatial variability of spotted alfalfa aphid, Therioaphis maculata Buckton and coccinellid lady beetles in alfalfa fields. Global positioning and geographic information systems were used for spatial sampling and mapping the distribution pattern of these insects. This study was conducted in three alfalfa fields with areas of 7.3, 3.1 and 0.5 ha and two growing seasons, 2013 and 2014. The 0.5 ha field was divided into 10 × 10m grids and 3.1 and 7.3 ha fields were divided into 30 × 30m grids. Weekly sampling began when height of alfalfa plants reached about 15cm and was continued until the cuttings of alfalfa hay. For sampling, 40 and 10 stems were chosen randomly in 30 × 30m and 10 × 10m grids, respectively and shaken into a white pan three times. Aphids and coccinellids fallen in the pan were counted and recorded. Semivariance analysis indicated that distribution of T. maculata and coccinellids was aggregated in the fields. Comparison of the distribution maps of aphid and lady beetles indicated that there was an overlap between the maps, but they did not coincide completely. This study revealed that relationship between spotted alfalfa aphid and lady beetles was spatially dynamic. These results can be used in biological control and site-specific management programs of T. maculata.

Small walnut aphid (SWA) Chromaphis juglandicola is an economic pest of walnut trees. Population fluctuation of SWA was studied in Mamaghan walnut orchards (East Azarbaijan Province, Iran).Three factors affecting population density of SWA, including vertical divisions of canopy (upper and lower half), geographical orientations of canopy (at four levels) and elongation of branch (basal and distal ends), were investigated. Sampling unit was a cluster of five leaves. Totally 128 samples were taken weekly from all strata upon eight chosen trees, repeating 30 times during the season. Natural enemies also were counted. The first SWA individuals were observed early May, consisting of first instar larvae and alate females. A sudden population increase occurred in mid-May. Maximum 40 aphids/leaf were observed in early June with first and second instars dominant, followed by a sudden decline in late June. A small peak was observed at early October. A partial tendency was observed toward north of canopy, at basal half of downward branches. Positive linear correlation between natural enemie's and SWA populations suggests density dependence. Moreover 2-4 week delay was present between them. Trioxys pallidus (Holliday) was dominant natural enemy in the region. Contrary to previous works, overwintering stages of the SWA in the region were predominantly developed stages (third and fourth instars as well as pre-reproductive winged females).

Colorado potato beetle is one of the most important insect pests of potato plants. Frequently and prolonged use of chemical pesticides for controlling this pest, has caused environmental pollution, pest resistance to pesticides and destruction of natural enemies. Some herbal extracts are more degradable and relatively safer than most of the synthetic insecticides and can be used as suitable alternatives in integrated management of Colorado potato beetle. In this study, the effects of leaf extracts of Juglans regia, Sambucus ebulus, Artemisia annua, Satureja sahendica and Salvia sahendica were studied on 2nd instar larvae of Colorado potato beetle, Leptinotarsa decemlineata in laboratory conditions at 26 ± 2 °C, 55±5% RH and a photoperiod of 16:8 (L:D). Potato leaves were treated with 0.625, 1.25, 2.5, 5 and 10% concentrations of the plant extracts using leaf- dipping method. Control leaves were dipped in either methanol or distilled water only. Each treatment consisted of 20 up to 24 h old 2nd instar larvae and had three replicates. Mortality of the larvae was recorded 24, 48, 72 and 96 hours after treatment. The results showed that extracts of Juglans regia, Satureja sahendica and Artemisia annua were more toxic to 2nd instar larvae of the Colorado beetle than Salvia sahendica and Sambucus ebulus. Ninety six hours after treatment, 10% concentration of J. regia, S. sahendica and A. annua caused 93.33, 91.67 and 73.33% mortality and 5% concentration of these extracts caused 58.9, 100 and 48.2% mortality in Colorado potato beetle larvae, respectively. As expected, the mortality decreased with decreasing concentrations. According to the high mortality percent, especially in high concentrations, the extracts of these plants, can be used as potential botanicals for integrated management of Colorado potato beetle.

In this study, spatial distribution pattern of alfalfa leaf and root weevils was determined using geostatistics. This study was conducted in four alfalfa fields (0.4, 0.5, 3.1 and 7.3 ha) located in the experimental farm of Faculty of Agriculture University of Tabriz, Tabriz, Iran. The 0.4 and 0.5 ha fields were divided into 10 × 10 m grids and 3.1 and 7.3 ha fields were divided into 30 × 30 m grids. Weekly samplings were started at the end of winter and continued until the last clipping of the yield. Depending on the height of alfalfa plants, a 1 × 1 m quadrat and a standard sweep net were used for weevils sampling. One sample was taken from each grid. Spatial analyses of data were conducted using GS 5.1.1. Degree of dependence (DD) was used for determining spatial dependency of data and spatial distribution pattern of alfalfa weevils. Distribution maps were produced using ArcGIS 9.3. DD values were > 26% for 97 out of 116 data series, indicated that weevils are aggregately distributed in the alfalfa fields and has medium to strong spatial dependency. These results provide useful information about ecology of leaf and root weevils in the alfalfa fields and can be used in site-specific management programs.

Small walnut aphid (SWA), Chromaphis juglandicola (Kaltenb), is a pest of walnut trees in many regions. Population fluctuations as well as spatial pattern of distribution of small walnut aphid (SWA) was studied during growing season of 2012 by weekly samplings in Mamaghan walnut orchards, East Azerbaijan, Iran. Sampling program was conducted for about six months from late April to November. All stages of aphid were counted separately on 128 clusters of leaves collected from eight walnut trees. Discrepancy of the sampling data from whether Poisson (random) or negative binomial (aggregation) statistical distributions was investigated by Pearson's Chi square test. Disregarding stages of SWA, goodness of fit tests were carried out with total populations. Contagiousness indices as well as Taylor's power low were also used to distinguish the pattern of distribution. In all samplings from 10 May to 10 August, data fitted to negative binomial distribution only with two exceptions. Afterward population deeply declined and well fitted to random pattern up to 20 September. Relative increase of population in late season leads to a tendency to aggregation once again. As a conclusion, SWA colonization begins as random; aggregation occurs following on site reproduction of females and finally random situation returns following depletion of patches. A second aggregation occurs late in the season when autumnal natality regains. Taylor's power low also showed a clumped pattern with a slope of b=1.55.

Sunn pest Eurygaster integriceps Puton is the most important pest of wheat and barley in Iran. Using biological control agents, within which egg parasitoids are the most promising agents, is an effective tactic of management of this pest. For optimal use of biological control agents, one needs to beware of efficacy of them in different ecological conditions. Regarding priority of the parasitoids in their emergence in wheat fields compared to their host in spring, they are in a high risk of encountering with durations of host absence early season; hence in this study we evaluated the effect of different intervals of host unavailability upon the egg parasitoids in terms of parasitism rate. The parasitic wasp, Trissolcus grandis (Thomson) (Hym., Scelionidae), which is dominant species in Iran wheat fields was chosen for experiments. The wasp specimens were collected from Garamalek and Kujuvar villages, located in west of Tabriz. The experiments were conducted under laboratory conditions (25±1ºC, 50±10% RH and 16L: 8D h photoperiod) with five treatments including a control (complete access of wasps to the hosts), access every other days, every third days, once a week and complete access following a six day prevention period in 15 replications. The results revealed that parasitism rate decreases by increasing unavailability intervals of host. Results showed that a partial compensation was occured in all treatments except young females of T. garndis in the second treatment that the wasp could completely overcome host deficiency of the previous days during first few days of her lifespan.

In this study, lethal effects of indoxacarb and methoxyfenozide were assessed on Colorado potato beetle. To do the bioassays, potato leaflets were dipped in aqueous suspensions of the insecticides and the larvae were transferred on the leaflets after drying. The results were recorded 24 and 72h after treatment for indoxacarb and methoxyfenozide, respectively. LC50 of methoxyfenozide for the 1st instars was 80.6 mg ai/l and LC50 values for indoxacarb were 4.5, 6.85, 9.42 and 7.28 mg ai/l for 1st, 2nd, 3rd and 4th instars, respectively. LC50 value of methoxyfenozide for 1st instar was relatively high; therefore lethal concenteration was not estimated for next instars. Because of the importance of sublethal effects in insect growth regulators (IGRs) application, the sublethal effects were evaluated for methoxyfenozide by using its LC1 and LC7. First instars were fed on treated leaves for 48 or 96h and then on untreated leaves; and were monitored until adult stage. Fecundity of these adults was evaluated. The number of larvae developed to prepupae and adults was significantly lower in sublethal concentrations of methoxyfenozide compared with control. The treated larvae did not reach next generation. The results indicated that indoxacarb and methoxyfenozide were effective against Colorado potato beetle; and if they perform equally well in the field, they can be suitable candidates for management of this important pest.

Beet armyworm، Spodoptera exigua (Hübner) is an important pest of field crops with a wide range of host plants. Using safer insecticides with different modes of action and lower possibility of development of resistance such as insect growth regulators (IGRs) would be useful for effective control of this pest. In this study، effects of three IGRs namely methoxyfenozide، lufenuron and flufenoxuron were assessed on 1st instar larvae of S. exigua. To investigate the effect of insecticides، bioassays were performed using diet incorporation and leaf dipping methods. Mortalities were recorded 144 h after treatment. The LC50 values obtained for methoxyfenozide، flufenoxuron and lufenuron were 0. 154، 0. 254 and 2. 398 mg ai/l، in diet incorporation method; and 1. 302، 0. 427and 3. 510 mg ai/l in leaf dipping method، respectively. Comparison of the LC50 values for the insecticides revealed that the LC50 values for the treated insecticides were significantly different in both bioassay methods. The results indicated that in both bioassay methods، lufenuron had the lowest toxicity against the 1st instars of beet armyworm. It was revealed that all insecticides tested were effective against 1st instars of beet armyworm at low concentrations. If similar results are obtained in field conditions، due to fewer unwanted effects of these insecticides، they can be considered in beet armyworm control programs.

Sunn pest is considered as the most important insect pest of wheat and barley in Iran. Different studies have shown that various biotic and abiotic factors affect sunn pest populations. These factors can influence the population density of the pest which in turn can play a role in the control of the pest. In this study the relationship between sunn pest population fluctuations and climatic conditions, the area under wheat and barley cultivation as well as the area under chemical control was investigated. In addition, the possible influence of overwintering adults’ weight and environmental factors on sunn pest mortality in the overwintering sites was studied. Field data were collected from six infested counties of East Azarbaijan province, including Tabriz, Bostanabad, Sarab, Mianeh, Heris and Hashtrood during three study years. From the variables under study, only mean weights of the overwintering insects, altitude, mean monthly minimum relative humidity, as well as rainfall during the months of December, January, February and March indicated significant relationships with sunn pest mortality in the overwintering sites. The relationship between the area under wheat and barley cultivation and sunn pest population changes was not significant but there was a close relationship observed between the area under chemical control and sunn pest population fluctuations. Similar studies in other regions with long history of sunn pest outbreaks will produce valuable information that can be helpful in predicting sunn pest outbreaks.