203 research outputs found

    Effect of four powdered spices as repellents against adults of Rhyzopertha dominica (F.), Sitophilus granarius (L.) and Tribolium castaneum (Herbst) in laboratory conditions

    Get PDF
    Studies were conducted to test the repellency of four powdered spices, black pepper (Piper nigrum.), chili pepper (Capsicum annuum), cinnamon (Cinnamomum aromaticum) and turmeric (Curcuma longa), against three stored-product insects, the lesser grain borer, Rhyzopertha dominica, the granary weevil, Sitophilus granarius and the red flour beetle, Tribolium castaneum. The cup bioassay technique was used, to determine the response of insects to potential repellents by measuring their movement from treated grain. The device is made of galvanized screening with 2 mm perforations shaped into a cylinder of 6 cm diameter and 15 cm high, with a mesh bottom, and is placed in the centre portion of plastic container of 15 cm diameter and 15 cm high. The powdered spices were poured into 200 g of wheat mass by a long-stemmed funnel at concentrations of 0, 0.25, 0.75, 1.5 and 2.5% on (w/w) basis. Twenty adults of three species are released into the centre of the grain mass in the container through a long-stemmed funnel. The experiments were conducted at room conditions. The number of trapped insects was determined at 3 different intervals after the introduction of the insects. Results showed that all tested plant powders had repellent activity against the three stored-product insects. Adults of S. granarius repelled faster, followed by T. castaneum and R. dominica. At the highest concentrations and intervals, wheat grains treated with cinnamon powder were the most repellent to adults of S. granarius (up to 92.5% after 1 h), followed by chili pepper treatment for T. castaneum (up to 72.5% after 6 h) and black pepper treatment for R. dominica(up to 58.75% after 24 h).Keywords: Repellency, Spices, Rhyzopertha dominica, Sitophilus granarius, Tribolium castaneu

    Some biological characteristics of the Batrachedra amydraula Meyrick (Lepidoptera: Batrachedridae) on main varieties of dry and semi-dry date palm of Iran

    Get PDF
    Although Iran is the leading producer of dates in the world, only 10% of its product is exported. One of the factors which limits exportation is postharvest pests. Lesser date moth (Batrachedra amydraula) is one of these postharvest pests. This pest is found in all date palm plantations of Iran. The biology of this pest has not been studied under laboratory conditions on main varieties of stored date in Iran. In this research some biological characteristics including survivorship, developmental time, fecundity, oviposition and postoviposition period, and longevity of adults on date palm varieties Zahedi, Ghasb, Rabbi, Deyri and a semi-artificial diet were studied. All experiments carried out at constant temperature room (30 ± 0.5 °C and 55 ± 5% r.h.). Highest survivorship of egg and combined larval and pupal stages were 86 and 85% respectively on semi-artificial diet. Shortest total development time from egg to adult was 43 days for males and 43 days for females on semi-artificial diet. Longest total development time was 69 days for male and 65 days for female on Ghasb variety. The highest (45 eggs per female) and lowest (25 eggs per female) fecundity occurred on the Deyri variety and semi-artificial diet, respectively. Results of this study would be useful for making pest management decisions in date palm storage.Keywords: Lesser date moth, Batrachedra amydraula, Biology, Date pal

    Effect of diethyl maleate on toxicity of linalool against two stored product insects in laboratory condition

    Get PDF
    Essential oil extracted from plants has been widely investigated for pest control properties, with some proving to be toxic in insect pests. In this study, effect of the synergist diethyl maleate (DEM) on toxicity of one monoterpenoids, linalool was studied against two most common stored-product insects such as Callosobruchus maculatus and Rhyzopertha dominica. Diethyl maleate was combined in mass ratios (1:8 and 1:4) with acetone used and applied on C. maculatus and R. dominica adult. Five concentrations of linalool were tested with four replications at 24 and 48 h with 30 adult insect in each replication. After 24 h of exposure, the LC50 values were estimated to be 23.61 and 31.01 μl/l air, and after 48 h, they were 15.07 and 21.84 for each insect, respectively. A combination of inalool with the synergist after 24 h of exposure, the LC50 values was estimated to be 11.93 and 13.07 μl/l air and after 48 h, they were 7.38 and 7.93, respectively for each insect. The synergist is able to block the specific system of enzymes involved in selection of tolerance in susceptible generations. Diethyl maleate is an inhibitor of glutathione S-transferase (GST) activity. These results show that diethyl maleate decrease doses of linalool.Key words: Diethyl maleate, linalool, LC50, synergism, Rhyzopertha dominica, Callosobruchus maculatus

    The rovibrational spectrum of BeH, MgH and CaH at high temperatures in the X 2Σ+X\,{}^2\Sigma^+ state: a theoretical study

    Full text link
    Accurate line lists for three molecules, BeH, MgH and CaH, in their ground electronic states are presented. These line lists are suitable for temperatures relevant to exoplanetary atmospheres and cool stars (up to 2000K). A combination of empirical and \textit{ab initio} methods is used. The rovibrational energy levels of BeH, MgH and CaH are computed using the programs Level and DPotFit in conjunction with `spectroscopic' potential energy curves (PECs). The PEC of BeH is taken from the literature, while the PECs of CaH and MgH are generated by fitting to the experimental transition energy levels. Both spin-rotation interactions (except for BeH, for which it is negligible) and non-adiabatic corrections are explicitly taken into account. Accurate line intensities are generated using newly computed \textit{ab initio} dipole moment curves for each molecule using high levels of theory. Full line lists of rotation-vibration transitions for 9^9BeH, 24^{24}MgH, 25^{25}MgH, 26^{26}MgH and 40^{40}CaH are made available in an electronic form as supplementary data to this article and at \url{www.exomol.com}.Comment: MNRAS (in press

    Biological characteristics of Cadra cautella (Lep.: Pyralidae) on different varieties of stored date palm fruit of Iran

    Get PDF
    The postharvest pests, including the dried fruit moth Cadra cautella Walker, are important limiting factors in the exportation of dates. The biology of C. cautella, its survivorship, developmental time, fecundity, oviposition, post oviposition period, as well as longevity of the adults were studied on four date palm varieties of Zahedi, Piarom, Rabbi, and Deyri under laboratory conditions in Iran. The experiments were carried out at constant temperature room (29 ± 1 °C, 60 ± 5% RH and photoperiod 16L: 8D hrs.). The highest survivorship of egg and larval stages was recorded 92.66%, 85.89% on Zahedi and 100% for pupal stage on Rabbi. The shortest larval period was 32.93 ± 1.41 days and 33.37 ± 1.87 days on Deyri and Zahedi respectively. The shortest total development time for males from egg to adult was 40.91 ± 1.15 days and 40.97 ± 1.59 days on Zahedi and Deyri respectively and for females was 43.76 ± 2.47 days on Deyri. The longest total development time for males was 47.61 ± 1.50 days on Piarom and for female was 55.88 ± 2.31 and 55.37 ± 3.87 days on Piarom and Rabbi respectively. The highest (247.00 ± 8.53 eggs per female) and lowest (147.40 ± 12.06 eggs per female) fecundity occurred on Zahedi and Piarom, respectively. The date palm varieties Zahedi, Deyri, Rabbi and Piarom are found to be on preferrence order for C. cautella. The results of this study would be useful for planning pest management strategies in date palm fruit storages

    Initial and delayed mortality of Rhyzopertha dominica (Col.: Bostrichidae) and Tribolium castaneum (Col.: Tenebrionidae) adults exposed to Silico-Sec® formulation of diatomaceous earth

    Get PDF
    Efficacy of temperature and exposure interval on the toxicity of Silico-Sec®, a diatomaceous earth formulation, was determined on 7-14 days old adults of Rhyzopertha dominica (F.) and Tribolium castaneum Herbst under laboratory conditions at 22, 27, 32 ºC and 65 ± 5% R.H. Insects were exposed for 8-72 hours to diatomaceous earth at the rate of 10 g/m2 on a filter paper inside plastic Petri dishes separately. Then the initial mortality was counted and, to determine delayed mortality, live individuals were held for a week in clean Petri dishes without food at the same conditions of previous experiment. LT50 values of initial mortality for R. dominica were 21, 12 and 9 hours at 22, 27, 32 ºC, respectively, and in the case of T. castaneum, they were 52, 27 and 18 hours at the same temperatures. The LT50 values indicated that R. dominica was more sensitive to Silico-Sec® than T. castaneum under identical conditions. Results indicated that the initial mortality of both species was significantly lower at 22 ºC in comparison with 27 and 32 ºC, and a direct relationship between temperature and exposure period was observed. Mortality percentage of both storage pests was higher after a week than initial mortality. Therefore, Silico-Sec® can be recommended as a structural treatment of stored grain facilities

    Study on the resistance components in 33 commercial potato cultivars to Colorado potato beetle, Leptinotarsa decemlineata (Col.: Chrysomelidae)

    Get PDF
    Greenhouse and field experiments were conducted to evaluate the resistance components in 33 potato commercial cultivars to Colorado potato beetle, Leptinotarsa decemlineata (Say) in 2008. In a field choice test, the numbers of attracted beetles to the cultivars was determined as antixenosis index. To evaluate the antibiosis, potato tubers were planted in pots under greenhouse conditions and on each pot, one sleeve cage was set up, in which 15 first instar larvae were released and reared. The Larval weight after 12 days of releasing, mortality percentages of larvae and pupae and the durations of developmental stages were analyzed as the antibiosis indices. To study the level of tolerance of cultivars, the infested and non infested plots were isolated and arranged based on a randomized complete block design in field. In infested plots, each plant was infested by 40 medium larvae (second and early third instars) 15 days prior to the blooming of plants. At the end of the season, defoliation and yield loss among infested plots were determined and compared to non infested plots for each cultivar. Significant differences were observed in all studied traits. The cultivars Cardinal, Carlita and Sinja showed antixenosis effects with the least numbers of attracted beetles, whereas cultivars Carlita, Sinja, Delikat, Aparet and Bridjet showed antibiosis effects in comparison to the others. The cultivars Santana, Satina, Nicola and Bridjet showed tolerance to damage of the pest. Using cluster analysis, UPGMA procedure was based on Euclidean distance and 33 experimental cultivars were grouped in 7 distance groups

    The curious case of thin-body Ge crystallization

    Get PDF
    The authors investigate the templated crystallization of thin-body Ge fin structures with high aspect ratios. Experimental variables include fin thickness and thermal treatments, with fin structures oriented in the direction. Transmission electron microscopy determined that various crystal defects form during crystallization of amorphous Ge regions, most notably (111) stacking faults, twin boundaries, and small crystallites. In all cases, the nature of the defects is dependent on the fin thickness and thermal treatments applied. Using a standard 600 degrees C rapid-thermal-anneal, Ge structures with high aspect ratios crystallize with better crystal quality and fewer uncured defects than the equivalent Si case, which is a cause for optimism for thin-film Ge devices. (C) 2011 American Institute of Physics. (doi:10.1063/1.3643160

    Poor prognostic clinicopathologic features correlate with VEGF expression but not with PTEN expression in squamous cell carcinoma of the larynx

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to assess the relationship between expression of vascular endothelial growth factor (VEGF) and phosphatase and tensin homolog deleted in chromosome ten (PTEN), angiogenesis and clinicopathological parameters of squamous cell carcinoma of the larynx.</p> <p>Methods</p> <p>We examined immunohistochemical expression of VEGF and PTEN and CD34 for microvessel density (MVD) in sections of formalin-fixed, paraffin embedded tissue blocks of 140 patients with squamous cell carcinoma of the larynx. The intensity of VEGF and PTEN staining and the proportion of cells staining were scored.</p> <p>Results</p> <p>The tumor grade was not significantly related to PTEN expression, but it was to VEGF expression (p = 0.400; p = 0.015, respectively). While there was no significant relationship between PTEN expression and tumor size and cartilage invasion (p = 0.311, p = 0.128), there was a significant relationship between the severity of VEGF expression and tumor size (p = 0.006) and lymph node metastasis (p = 0.048) but not cartilage invasion (p = 0.129). MVD was significantly higher in high-grade tumors (p = 0.003) but had no significant relationship between MVD, lymph node metastasis, and cartilage invasion (p = 0.815, p = 0.204). There was also no significant relationship between PTEN and VEGF expression (p = 0.161) and between PTEN and VEGF expression and the MVD (p = 0.120 and p = 0.175, respectively).</p> <p>Conclusions</p> <p>Increased VEGF expression may play an important role in the outcome of squamous cell carcinoma of the larynx. PTEN expression was not related to VEGF expression and clinicopathological features of squamous cell carcinoma of the larynx.</p

    Mutations of PIK3CA in gastric adenocarcinoma

    Get PDF
    BACKGROUND: Activation of the phosphatidylinositol 3-kinase (PI3K) through mutational inactivation of PTEN tumour suppressor gene is common in diverse cancer types, but rarely reported in gastric cancer. Recently, mutations in PIK3CA, which encodes the p110α catalytic subunit of PI3K, have been identified in various human cancers, including 3 of 12 gastric cancers. Eighty percent of these reported mutations clustered within 2 regions involving the helical and kinase domains. In vitro study on one of the "hot-spot" mutants has demonstrated it as an activating mutation. METHODS: Based on these data, we initiated PIK3CA mutation screening in 94 human gastric cancers by direct sequencing of the gene regions in which 80% of all the known PIK3CA mutations were found. We also examined PIK3CA expression level by extracting data from the previous large-scale gene expression profiling study. Using Significance Analysis of Microarrays (SAM), we further searched for genes that show correlating expression with PIK3CA. RESULTS: We have identified PIK3CA mutations in 4 cases (4.3%), all involving the previously reported hotspots. Among these 4 cases, 3 tumours demonstrated microsatellite instability and 2 tumours harboured concurrent KRAS mutation. Data extracted from microarray studies showed an increased expression of PIK3CA in gastric cancers when compared with the non-neoplastic gastric mucosae (p < 0.001). SAM further identified 2910 genes whose expression levels were positively associated with that of PIK3CA. CONCLUSION: Our data suggested that activation of the PI3K signalling pathway in gastric cancer may be achieved through up-regulation or mutation of PIK3CA, in which the latter may be a consequence of mismatch repair deficiency
    • …
    corecore