PLANT PROTECTION JOURNAL
Year:2013 | Volume:5 | Issue:1 (14)|Papers Count:13

Tortrix viridanais a serious pest of oaks in the Kamfirooz oak forests. Oak bud tortricid (Tortrix viridana) has five larval instars in Kamfirooz oak forests. The pest overwinters as diaposed eggs. The first larval instar emergence coincides with tree budburst when they enter bud scales. First instar larvae appear between 10th to late march, depending on weather condition. Weather parameters such as low temperature at the time of egg hatching determine losses of the pest to the host tree. First, second, third, fourth and fifth instars of the pest take 4-7, 5-8, 5-8, 6-12 and 7-14 days respectively. Pest larvae make their feeding sites by attaching leaves in clusters through webbing. Larvae suspend themselves from a fine silken thread until they find a suitable feeding site and when there is a crowd of larvae on the some branches of the trees, larval movement between trees through hanging can be facilitated by wind. Many predators including spiders, ants, beetles and occasionally birds feed on pest larvae. The pest finishes its larval stages between 26 and 47 days (with an average 31.5 days). Pupal stage lasts 1-2 weeks. Trees can offset pest damages after pest outbreak, provided rainy winter precede, but if pest outbreak occurs in a year with low precipitation followed by a dry and hot summer, high losses due to pest will be unavoidable. Egg, larva, pupa and adult temporal distribution frequencies were 72.61, 10.14, 2.73, and 14.52 percent respectively. Direction had no significant effect on pest damage. Pest moths emerge during late April up through mid may. Moth population reaches its peak within 2-3 weeks after its appearance, and gradually disappears after its unimodal peak. Swarming as a social phenomenon may be observed during the emergence of adults. Twenty species of Aranidae belong to more than 7 families including Lycacidae, Oplinoidae, Clubionidae, Araneidae, Ulobridae, Phomicidae, Salticidae, four species of Coleoptera including Tenebrionidae (one unidentified species) and three coccinellids (Coccinellidae) as well as four species of Hymenoptera were among frequently collected natural enemies of the pest. Population dynamics of Exochomus quadripustulatus, one of the important coccinellids was also studied in sampling plots.

Hover flies (Diptera: Syrphidae) are considered as one of the most important natural enemies of aphids, and one of the most useful pollinators of plants. Their larvae are predators of aphids and they have an important role in ensuring biological balance. In this study, which were performed in Garmsar region in 2010, these flies were collected and identified. The species diversity of these insects was measured by indexes of Shanon-Winer (H´), Brilloun (Ĥ), and Margalov (Dmg). In the faunistic studies, 16 species belonging to 10 genera and 2 sub-families, were identified, among them the species, Eupeodes lapponicus, is considered as the new record form Iran. The maximum diversity and abundance of hoverflies in Garmsar were as Ĥ=1.125, H´=2.247, Dmg=22.878 at the first week of Khordad month (end of May). Also, Episyrphus balteatus is dominant speciesin Garmsar region.

The olive fruit fly, Bactrocera oleae (Diptera: Tephritidae) is the most important and widespread pest in the olive growing countries in the world. The larvae feed upon the pulp, resulting in a significant quantitative and qualitative loss in the production of table olives and oil. In this research, infected fruits from infected areas were collected and biological and reproductive parameters were evaluated at 27±1oC, 60-70% RH and photoperiod of 16L: 8D on olive fruit, Zard variety. Because of internal function of immature stages of the pest, we supposed that the gross hatch rate was equal to 1 and survival rate (lx) of adults was compared with the initial egg number. Results showed that incubation period of eggs, larval and pupal stages lasted in 3.26±0.095, 13.13±0.28 and 9.13±0.34 days respectively. Development time of the pest in suitable condition was 25.53±0.48 days. Pre-oviposition time, oviposition time and post-oviposition time was 5.64±0.31, 51.64±1.73 and 4.07±0.68 days respectively. The average of adult longevity for males was 38.57±2.56 and for females was 61.36±2.15 days. The total number of laid eggs laid in suitable conditions was 214.25±22.38 per female (139-256). The sex ratio was 1.1: 1, female: male. The survival rate until last stages of life cycle was equal to 1 but in this time some females was dead that it appeared as fluctuations in the rate. The gross and net fecundity and fertility rate of the pest on olive fruits was 118.20 and 46.97 respectively, because the gross hatch rate was supposed equal to 1. Mean egg per day was 1.90 and mean eggs/female/day was 0.89. Mean fertile eggs per day and mean fertile eggs/female/day were equal to 1.90 and 0.89 too. Results of showed that generation time (T) was 58.18 days, doubling time (DT) was 8.88 days, finite rate of increase (l) was 1.08 and intrinsic rate of increase (rm) was 0.078.

Armored scale, Pseudaulacaspis pentagona, is the most important pest on kiwifruit in the North of Iran.The aim of this project was theprecise usage ofwinter oil spray and pesticides for control the pest with minimum side effect on its parasitoeid (Prospaltella berlesei). For evaluating of emulsified oils against the pest in the winter the following treatments were used: emulsified oil at rate of 0.5%, 1%, 1.5%, 2%, Chlorpyrifos 0.15%+emulsified oil 1% and control (only water). In addition, the effect of Pyriproxyfen, Buprofezin and Chlorpyrifos at rate of 0.05, 0.05 and 0.15 % respectively in comparison with control were sprayed on crawlers of P. pentagona in the spring. The mortality percentage of pest and its parasitoide was evaluated. The results indicated that, Chlorpyrifos 0.15%+emulsified oil 1% and emulsified oil 2% caused the most mortality in over wintering generation of pest and its parasitoid too. Also, spring application of Chlorpyrifos 0.15% caused the most mortality in crawlers and parasitoid while Pyriproxyfen and Buprofezin had reliable effect on pest with moderate effect on its parasitoid and can use instead of organophosphate pesticides.

Due to chemical and synthetic pesticides hazards on the environment and the human health, trend to using botanical and natural pesticides increased. Eucalyptus plant as a potential plant for pest control can be studied for this purpose. This experiment was conducted to investigate the insecticidal effects of hexane extract of three species eucalyptus (Eucalyptus globules, E. microtheca & E. camaldulensis) on different developmental stages of Saw-toothed grain beetle (Oryzaphilus surinamensis) In this experiment larvae and adult were exposed to eucalyptus hexane extract for 24 hours under laboratory conditions 28±1oC, 65±5% RH. LC50 values of three Eucalyptus hexane extract (E. microtheca, E. globules, E. camaldulensis) were estimated 1507, 1552, 1608 ml/l air and 2078, 2172, 2229 ml/l air for adult and larval stage respectively. According to values calculated, the adults insect were more susceptible than larval stage to eucalyptus hexane extract.

The root-knot nematode, Meloidogyne javanica is one of the most important pathogens in many crops, especially in tomato. Formation of giant cells by nematode is the most important histological changes in disease process. Two arbuscular mycorrhizal fungal species, Glomus mosseae and G. intraradices were used to study the effects of arbuscular mycorrhizal fungi on pathogenicity and histopathological changes of root-knot nematode, in a completely randomized design, performed in glasshouse. Fungi and nematode were propagated on white clover and tomato, respectively. Nematode-related factors and pathogenicity indices were evaluated, after the nematode completed three generations. Analysis of variance showed the positive effect of mycorrhizal fungi on nematode damages. Mean comparison of the number and size of giant cells were showing significant difference between mycorrhizal and non-mycorrhizal plants. Thus mycorrhizal fungi caused reduction in number and size of giant cells in plants infected with nematode, but decrese in juvenile development.

In order to evaluate the rotation potential of different cultivars of oilseed radish (Rhaphanus sativus oleifera) named Adagio, Luna, Colouel and Accent on quantitative and qualitative Characteristics of Sugar Beet (Zarghan cultivar) and reduction of rhizomania infection severity, an experiment was conducted using Latin Square Design with five replications in Zarghan station in 2009-2011 in Fars province. The treatments were applied in first year as 1- no trap plant (check), 2- Adagio, 3- Luna, 4- Colouel, 5- Accent, and in second year Zarghan cultivar was planted in the same plots. Quantitative and qualitative traits and rhizomania infection severity measured after harvest. Results of compound analysis showed that the effect of rotation with trap plant cultivars on qualitative traits in Zarghan cultivars was not significant, but based on Friedman test, rhizomania infection severity in cultivated plots with trap plant was significant in 5% probability level so that in plots that Luna and Accent had been cultivated mean of disease degree was 1.85 and 2.5, respectively, that was less than other treatments. The biomass produced in the trap plant Luna and Accent less than other cultivars and their impact on disease reduction was remarkable. The effect of Trap plant compared to control treatment (without traps planted) on root yield and sugar yield was very evident in Zarghan comparison to control that root and sugar yield was reduced. In the control plot (without trap plant) the lowest root yield (36.65 t/ha) and sugar yield (6.28 t/ha) were included in separate groups. Acording to results it can be said that crop more than two years rotation with trap plant and using relatively tolerant sugar beet cultivars, can use to decrease virus growth potential and increase quantity in sugar beet.

Rhizoctonia root rot and crown rot of bean, caused by Rhizoctonia solani is one of the most important diseases of this crop in Iran. In this study, during 2004-2005, plant and soil samples were collected from the main bean-growing areas in Tehran province and totally, 81 isolates of the fungus were obtained.The morphological characteristics of the isolates including the color of colony, production of aerial mycelia, shape and size of sclerotia, the diameter of hyphae and the number of nuclei per cells were surveyed. After staning the nuclei, all of the isolates except two, were characterized as multinucleous. Anastomosis studies showed that 81.3% of the isolates belonged to the anastomose group 4 (AG-4), 16.04% to AG-6 and two isolates to AG-2. The two last groups are first reports from common bean in Iran. Pathogenicity tests were carried out on common bean, Naz cltivar. The inoculum consisted of wheat and barly seeds colonized with the fungus in complete randomized blocks design. We identified high variation in the pathogenicity of isolates. All of the isolates, except those belonging to the anastomosis group 6 (AG-6) wer relatively aggressive. The isolates Rs21 and Rs71 showed the highest and the lowest pathogenicity, respctivly. Sixteen improved cultivars of navy bean, kidney bean, French bean, green bean were tested for resistance to the five highely pathogenic isolates Rs7, Rs18. Rs21, Rs62 and Rs74 in greenhouse. Results showed that, all of the cultivars were susceptible or semi-susceptible to R.solani and just two cultivars Goli and Sayyad kidney bean, showing the average disease severity (2.58 and 2.9 using the 1-5 scale) were semi-resistant to the disease.

This investigation was conducted to evaluate the effect of herbicides trifluralin, ethalfluralin, alachlor and metribuzin on mycellial growth of Rhizoctonia solani anastomosis group 4, the causal agent of cotton and soybean damping off. The experiments were carried out in 2011 at Department of Weed Research, Iranian Research Institute of Plant Protection, Tehran. At first stage, growth reaction of the fungal colonies to the herbicides on PDA was studied. Then, this reaction to discs contaminated with the herbicides, compared with not using herbicide control, in two series of experiments was investigated. The results of high concentration of herbicides in PDA indicated that growth of the fungal colonies on PDA containing trifluralin at 12500 or 25000 ppm, ethalfluralin at 17500 or 35000 ppm, alachlor at 20000 or 40000 ppm was completely inhibited. R. solani growth on PDA containing metribuzin at 2500 or 5000 ppm was not completely inhibited, but this treatments, compared with control, significant reduced mycellial growth of the pathogen. The experiment at lower concentrations of the herbicides showed that alachlor, trifluralin and ethalfluralin, resprctively at 509, 318 and 445 ppm, significantly reduced the colonies growth. Among the recent treatments, the effect of alachlor was significantly more than the others. Paper discs contaminated with herbicides at three different concentration, showed no evidence of their effect on mycellial growth of the pathogen.

During 2011-2012, a faunistic study was conducted to collect and identify on edaphic mites associated with apple trees in Eghlid region (Fars province) One species of pachylaelapidmites, Pachyseius humeralis Berlese, 1910, was collected and identified. This is the first record of Pachyseius humeralis in Iran.

Trichoderma species are cosmopolitan, typically soil-born, able to growth on plant debris and frequently dominant member of soil microflora. In this study, 20 fungal isolates include Trichoderma asperellum, T. atroviride and T. arundinaceum were isolated base on antiseptic methods from root and stem of different hosts. These species could be endophytic Trichoderma of Kurdistan Province that are reported for first time from Iran.

During 2012, a faunistic study was conducted to collect and identify the mites associated with carabid beetles in Marvdasht region (Fars Province), Neotrochometridium sensillum (Acari: Heterostigmata: Trochometridiidae) is collected and identified. The mite was found phoretic on ventral body, grasping hairs of thorax of carabid beetle, Siagona europaea.