PLANT PROTECTION JOURNAL
Year:2010 | Volume:2 | Issue:1 (5)|Papers Count:10

Bemisia tabaci Gennadius was introduced over one hundred years ago and has seriously damaged the farming and non-farming products in the tropical regions. Many biological factors including host widespread range, being multi-generations, high productive rate, ability to transmission of the plant viruses and developing resistant to insecticides have been created many problems for managing this whitefly. In this research the effect of five insecticides. i.e. Pyriproxyfen, Imidaclopride, Pymetrozine, Fenpropathrin and Buprofezin on B.tabaci have been studied in order to determine the least most effective insecticide. By using leaf sampling, three leaves were chosen from upper, middle and lower parts of three shrubs. Totally nine leaves were selected from each plot randomly and the mature insects of pest lodging under leaves were counted. In order to count nymphs and puparium, the leaf pests were separated from stems and counted under a Binocolar. Subsequently, the obtained data were statistically analyzed and grouped at levels of %1 and %5. The results showed that none of the 10 treatments has an acceptable impact on nymph and puparium population. However, in adult pest insects the treatments Pyriproxyfen (Ec 10%) 750 cc/ha, Imidaclopride (SC35%) 750 cc/ha, Pymetrozine (WG25%) 1 kg/ha, Pymetrozine (WG25%) 1.25 kg/ha have had far superior results compared to the control group.

The pistachio psylla, Agonoscena pistaciae Burckhardt & Lauterer, is a major pest of pistachio trees throughout pistachio producing regions in Iran. Nowadays, degree-day models are considered as one of the most important tools in integrated pest management and forecasting of pest status. The cumulative effective temperatures were calculated for different percentages of nymph based on the lower development threshold of 9.960C and upper development threshold of 32.50C and different biofix during years 2007 and 2008 under field conditions. The cumulative effective temperatures form 21 January to 75 percentage of nymphs for first generation was calculated 510 DD. To calculate the cumulative effective temperatures for generations 2 to 6, 75% of nymph of last generation was selected as biofix. The cumulative effective temperature for generations 2 to 6 based on 75 percentage of last generation was calculated 339, 333, 313, 389 and 337 DD respectively. The mean cumulative effective temperature from 75 percentages of nymphs of each generation to next generation was calculated 342±28.13 degree-day. By using degree-day model, we can determine the suitable control time of pistachio psylla.

Sugar beet Root aphid Pemphigus fuscicornis (Koch) (Hem. Aphididae) is an important sugar beet pest (Beta vulgaris L.) in many countries. Recently, this pest has attacked sugar beet fields in Borujerd, north of Lorestan province, Iran. In this research, resistance to sugar beet root aphid was evaluated in nine sugar beet genotypes, under laboratory conditions in a randomized complete design during 2001-2002. At first, sugar beet seeds were planted in a small plot, and were grown for about 50 days, and then plants were transplanted into a peat-vermiculite mix in pots. Five reproductive aphids were placed on the root mass before being transferred into the pot. The pots were transferred to an incubator (set at 20±2oC and 16h artificial light and 8h dark). Forty days after infestation, the incubator temperature was suddenly decreased to 5oC and then the aphids were counted. Results showed that, variety of Simin1 was highly susceptible, BR1 Karaj was moderately susceptible and two varieties of Polyrave and Dez Elit were moderately resistant.

Damask rose (Rosa damascena Mill.), a plant growing in low water area of Kashan (Iran), has economic importance. One of the pests of the plant is Epiblema aquana (Hubner) [=Notocelia raborana Den. &Sciff.] from Lepidoptera order and Tortricidae family. During 2000-2001 some aspects of pest morphology and biology were studied in rose gardens of Kashan region. By inspecting rose gardens in different regions of Isfahan province (Iran), host range of the pest was studied by inspecting different plants inside and margins of the rose gardens and infected regions were recorded. Results showed that the larvae start their feeding from early May. After formation of flower buds, they make a feeding nest, through spinning threads between buds and the nearest leaves. Larval feeding leads to destruction of small buds and damage to larger buds. Adults appeared from late June to early August and females laid the eggs in clusters, under leaves. In addition to damask rose, the pest could feed on other roses and also on fruit trees in the margins of rose gardens. The pest was distributed in different rose gardens of Kashan and Ghamsar regions. The highest density, however, belongs to Barzok region, which has the highest cultivation area of damask rose in the province.

During 2009-2010, A study was carried out to collect and identify the mites of the suborder Prostigmata in south of Kamfiruz region (Fars province).A new species of Adamystis Cunliffe, 1957, in the family Adamystidae was collected and identified. Record of this family and genus is new to the mites' fauna of Iran.

During 2009-2010, a faunistic study was carried out on the edaphic mites of the family Bdellidae in Fars Science and Research Center region and the mite Hexabdella sp. near maraugia Schyff, Theron & Ueckermann was identified. This is the first report of genus Hexabdella from Iran. Mites of the family Bdellidae are predators of insects and mites.

During 2008-2009 a faunistic survey was carried out to collect and identify mites of family Macrochelidae in Islamic Azad University Fars Science and Research Branch. A total of 6 species were collected and identificated of these Holostaspella ornata (Berles) is new record for fauna of Iran.

During 2009, in the course of the faunistic survey of mites related to mushroom in Seidan region, Fars province, one species from the Lardoglyphidae was collected and identified as Lardoglyphus konoi Sasa & Asanuma. This species is newly recorded from Iran in mushroom growing compost.

The cereal cyst nematode, Heterodera filipjevi, is recognised as one of the most important soil-borne pathogens limiting yield in many rain-fed wheat growing areas throughout the world. It also occurs in many cereal growing regions of Iran. Two pot experiments were conducted under field conditions to evaluate the response and tolerance limit of winter wheat cv. Sardari to infestation with different population densities of H. filipjevi. Pots were artificially infested with initial population densities (Pi) of 0, 2.5, 5, 10 and 20 eggs and second-stage juveniles (J2s)/g soil. Each treatment was replicated seven times during two successive growing seasons. Tolerance limits (T) of 0.8 and 0.6 eggs and J2/g soil for the grain yield were estimated in the first and second years respectively, with an average of 0.7 egg and J2/g soil for both years. Minimum relative yields were 0.4 at the Pi of 40 in the first year and 0.45 at the Pi of 64 in the second year for the grain yield. The final population of H. filipjevi increased with increasing the Pi levels. The maximum reproduction rates of the nematode were 4.6 and 3.9 at the lowest Pi of 2.5 eggs and J2s/g soil in the first and second years respectively.