نشریه آفات و بیماریهای گیاهی
سال نود و یکم شماره 1 (پیاپی 116، شهریور 1402)

Recognition of environmental factors and variables affecting the incidence and distribution of insect pests has always been considered by researchers as one of the strategic aims of pest control. Nezara viridula L. and Acrosternum millieri Mulsant & Rey. have been introduced recently as one of the most important pests of pistachio and almond products in the Yazd province of Iran. In this study, the effect of environmental variables on the presence and distribution of these species was performed using the maximum entropy method. The results of the Jacknife test for N. viridula showed that the variables of altitude and maximum temperature of the warmest month have the maximum effect on incidence and distribution when used separately.Finally, by observing the maps obtained from the species distribution model, "vegetation" for N. viridula and "altitude" for A. millieri were suggested as critical climatic factors in the presence and distribution of the studied species.

Field studies were carried out to evaluate the attractiveness of different food attractants viz. protein hydrolysate 10%, torula yeast 10%, yeast instant 7%, casein 5% and sugar molasses 10% towards the fruit fly, Bactrocera species in pear orchard. Different concentrations of food baits (as mentioned above) were prepared in 200 ml of water and transferred to locally designed traps made up of 1.5 liter cold drink plastic bottles. The traps were hung on fruit trees at a height of about 2 m and at appropriate distance from each other. No insecticide was used in the food attractants. Data were regularly recorded at weekly intervals on the total number of B. zonata or B. dorsalis captured their sex ratio and aggregate population density of both the species. Results showed that yeast instant attracted significantly higher population of B. zonata and B. dorsalis and hence the highest cumulative population of both species followed by treatment of sugar molasses and protein hydrolysate. Among all the treatments, torula yeast was found to be the least preferred attractant for B. zonata and B. dorsalis. Sex ratio (%) of B. zonata and B. dorsalis revealed that all the baits attracted significantly higher number of females than males with highest female percentage in protein hydrolyzate and the lowest in sugar molasses. The results showed that yeast instant, sugar molasses and protein hydrolysate were highly effective and could further be exploited in combination with certain chemicals to enhance their effectiveness and developing a strong fruit fly attractant.

Potato, as one of the strategic crops, plays an important role in the economy of the country. The potato golden cyst nematode (Globodera rostochiensis), was reported from Hamedan province in 2007. In present study, the reaction of 19 commercial potato cultivars and 23 advanced potato clones together with resistant and susceptible cultivars were evaluated against potato golden cyst nematode Globodera rostochiensis in greenhouse and field conditions. As the result, the cultivars Savalan, Jili, Sagita, Panamera and the clones 5/25, 870787, 1/27, 870861, 13/75, 1 were evaluated as susceptible. The cultivars Anosha, Banba, Kolomba, Kaiser, Fabula and clones 24/24, 19/75, 8701125, 11 and KSG613 were evaluated as resistant which could be introduced as the new resistant cultivars. The cultivars Khavaran, Boren and the clone 8708133 were evaluated as tolerant. The cultivars Challenger, Georgia and Taurus (commonly cultivated in Iran) were evaluated as susceptible. Besides the phenotypic evaluations, the molecular approches were also employed to amplify two TG689 and 57R markers linked to the H1 resistance gene in studied cultivars and clones.

In this research, the seeds of 12 sugar beet hybrids along with four control genotypes were planted in microplot conditions. After evaluating the roots against Rhizoctonia solani AG 2-2, the six genotypes that had the lowest amount of fungal infection were selected and tested for their reaction to Rhizomania virus disease. After examining ten soil samples from the farms of Kermanshah province and microplots located in Mahidasht research station, the contamination of the microplots of the experimental site with Rhizomania was confirmed based on serological and molecular methods. The seeds of six selected genotypes were planted in sterile soil and the seedlings were transferred to the microplate at the four-leaf stage. After harvesting, the roots were evaluated for BNYVV contamination using the ELISA method and based on Duncan's comparative test, they were divided into three groups. In general, due to the favorable resistance of the hybrid genotype (SB36*7112)* S1-92309 to both diseases, the use of the parents of this hybrid is suggested to continue for breeding experiments.

Plum fruit moth Grapholita funebrana is one of the most harmful pests of plum. In this research, the seasonal population fluctuation and host preference of the damaging plum moth population was investigated. Twenty six plum germplasms were used. The quantitative and qualitative characteristics of the fruits were evaluated. The cluster analysis method was used to separate cultivars and genotypes.Tthe degree of influence of different fruit characteristics on host preference was studied by calculating correlation and multiple regression analysis. The maximum index of effective larvae day was equal to 116.5 to 42.5 larvae per day for plum germplasms in late July to early August. The maximum activity of pest larvae was recorded with a slight delay in some cultivars such as Angelo, Gholaman, Kh-Kermanshah and Zojelo in late August to early September, and in others earlier in late June such as Kermanshah. The highest and lowest three-year average value of the preference index was 2.03 and 0.23 for Zojelo and 19 genotype, respectively. Various morphological and qualitative of the fruit characteristics including pH, core thickness, firmness of flesh tissue, ratio of length to diameter, engineering diameter, surface area and TSS were effective in the occurrence of larval host preference reaction. The fruit surface area, fruit width, engineering diameter and fruit fresh weight explained 27.1%, 13.2%, 22.9% and 12.7% of the host preference changes of plum moth larvae, respectively. The results of this research are important for the selection of suitable plum cultivars for the development of cultivation in the country.

Chilo suppressalis, is one of the destructive pests of rice in many rice producing countries, including Iran. Considering the adverse effects of using chemical pesticides in the rice crop ecosystem against striped stem pest, pheromones are also considered as an expensive pest management tool. The present research was conducted in two cropping seasons at Rice Research Institute of Iran, (Rasht). In this research, 5 treatments including: 1- sex pheromone with 1 trap per hectare, 2 - sex pheromone with 3 traps per hectare, 3- sex pheromone with 5 traps per hectare, 4- sex pheromone with 7 traps per hectare and 5- control (spraying granules of 10% Diazinon 15 kg/ha) was applied in the research field. The results of the present study showed that the least dead hearts and infestation of white heads, the number of counted larvae and the highest yield obtained from  using  the concentration of 2 mg of the effective substance of the sex pheromone of striped stem borer with 5 to 7 traps per hectare. Also the highest contamination of dead hearts and white heads, the number larvae and the lowest yield were observed in the treatments of one and three traps per hectar. According the results of the present study, it seems that the control of striped stem borer pest using sex pheromone creates a promising in an integrated pest management program.

Scale insects are the important pests of the forest, horticulture and crops, which may weaken plants. Zagros oak forests are one of the most important natural reserves of Kermanshah province that their protection is vital. More than 8,000 species of scale insects have been reported worldwide and 300 species of these insects recorded from Iran. In this research, which was carried out from 2021 to 2022 in Zagros oak forests, Kermes spatulatus specifically feeds on oak trees Quercus spp. is recorded for the first time from Iran. The oak branches and stems which infected with this scale insect were collected from Chalabeh and Dalahu regions in Kermanshah province. After being separated from the branches, the scales were clarified and microscope slides were prepared from them. Then macroscopic and microscopic characteristics of their adult insects and their first-instar nymph were evaluated and described; Adult female of this species shows different colors in two regions; Dalahu samples are black and Challabeh samples are orange in color. But the color of the first nymphal instar are same in the two regions. Also this scale was compared with close scale related species.

The khapra beetle, Trogoderma granarium (Everts) is one of the most important insect pests of stored products, especially wheat grains, in Iran and some other countries of the world. In this research, effect of various wheat genotypes including Heidari, Aftab, Gaskojen, Kouhdasht, Tirgan, N-91-9, and N-92-19 was studied on biology and two-sex life table parameters of T. granarium under 33 ± 1°C, relative humidity of 65 ± 5%, and a photoperiod of 14:10 (L:D) h. Our results showed that the immature period of T. granarium was the longest on N-91-9, Heidari, and Aftab. The net reproductive rate (R0) ranged from 9.03 offspring on N-92-19 to 34.13 offspring on Gaskojen. The lowest intrinsic rate of increase (r) was for T. granarium reared on Heidari, Aftab, N-91-9 and N-92-19. The results of this study indicated that Heidari, Aftab, N-92-19 and N-91-9 were unfavorable genotypes for T. granarium development and population increase. These genotypes could be used as one of the sources of resistance in management programs of T. granarium.

Increase of the population of grape cicada was occurred in the major vineyards of Zanjan province in 2012- 2015. Identification the damaging species and its growth process were carried out in four infected orchards located in Shenat vicinity of Abhar, Zanjan, Iran during two-year study from early June 2013. In each weekly visit, 30 grape bushes selected randomly in each orchard and were examined carefully to find the presence of nymph exit holes from the soil, exuviae, adult cicadas, egg laying clefts and incubated eggs. All the collected specimens were identified as Chloropsalta smaragdula Haupt 1920. First exit holes, larval exuviae, and adults were observed on June 11and 14, June 11and 14, June 16 and June 14 respectively; first egg laying symptoms on the newly grown shoots were also observed on July 2nd incubated on Aug. 2nd. Additionally, to prepare the preliminary distribution and infection rate map of the pest in the region ,three grape shrubs of three orchards in 40 villages in Abhar and Khorram- Dareh counties were examined for recording the percent of egg laying clefts to estimate the infection rates using the software of Arc view.

Tthis research was conducted with the aim of evaluating of two common spraying methods for Brevicoryne brassicae control during stemming stage and to introduce a more suitable method according to the technical parameters affecting the performance and efficiacy of spraying. The test was conducted in the form of a completely randomized design in three treatments and three replications based on the obtained results, for the tractor-mounted boom sprayer and tractor-mounted lance sprayer, the amount of consumed volume was 179 and 279 L/ha, respectively, the effective field capacity was 5.0 and 0.8 ha/hr, respectively, the field efficiency was 56.8% and 55.5%, respectively, the crop damage area obtained 3.85% and 4.45%, respectively, the spray quality coefficient was 1.96% and 3.31%, respectively, and the average drift was 21.0% and 35.7%. Also, there was no significant difference between the two sprayers in 3 and 7 days after spraying. However, 14 days after spraying, there was a significant difference between the treatments, and the spraying efficacy of the boom sprayer reached 83% and 41% for the lance sprayer. Considering the better results of the tractor-mounted boom sprayer and its greater spraying efficiency than the tractor-mounted lance sprayer, this method is recommended to control pests during the canola stemming stage.

Garlic is an herbaceous plant from the Alliaceae, which ranks second among Allium species after onions in terms of global production. Garlic is one of the most widely grown crops in Tarom County, Zanjan Province, Iran. Recently, a new disease with symptoms of severe yellowing and terminal drying of the leaves, known as garlic yellowing disease, was observed in many fields of Tarom County of Zanjan province. To identify the causal agent and assess the prevalence of garlic yellowing disease in Tarom, symptomatic leaves were collected from fields for three years. After isolation, the cause of garlic yellowing disease was identified as Stemphylium vesicarium, based on both morphological characteristics and sequencing of the rDNA-ITS, glyceraldehyde-3-phosphate dehydrogenase (gapdh) and calmodulin (cmdA) genomic regions. A severe epidemic of yellowing disease on garlic caused by S. vesicarium was found in all garlic fields in Tarom.

Scab disease caused by Venturia inaequalis is the most important diseases of apple in the world which causes serious damage, especially in areas with wet and moderate weather. In order to investigate the effect of fungicides on the time progression curve of apple scab disease in North Khorasan province, the experiment was conducted in the form of Randomized Complete Block Design with eight treatments and eight replications in Bojnord city. With the appearance of disease symptoms, samples were taken in a regular schedule every week until the disease progression was reduced in the control.  Disease Incidence and severity percentage of the disease in each tree were determined and statically analyzed. Using linear regression, disease progression curves were fitted with six growth models as conventional models including linear, exponential, monomolecular, logistic, log-logistic and Gompertz linearized. The results showed that the progression curves changes from the Gompertz model in the control samples by using of fungicides according to the efficiency of each treatment to the log-logistic model and finally to the monomolecular model.