171 research outputs found

    Cellular immune reactions of the sunn pest, Eurygaster integriceps, to the entomopathogenic fungus, Beauveriabassiana and its secondary metabolites

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    In this study, five morphological types of circulating hemocytes were recognized in thehemolymph of the adult sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae),namely prohemocytes, plasmatocytes, granulocytes, adipohemocytes, and oenocytoids. Theeffects of the secondary metabolites of the entomopathogenic fungus Beauveria bassiana oncellular immune defenses of Eurygaster integriceps were investigated. The results showed thatthe fungal secondary metabolites inhibited phagocytic activity of E. integriceps hemocytes andhampered nodule formation. A reduction of phenoloxidase activity was also observed. The datasuggest that B. bassiana produce secondary metabolites that disable several immune mechanismsallowing the fungus to overcome and then kill its host. This characteristic makes B. bassiana apromising model for biological control of insect pests such as E. integriceps

    Olfactory response of the predatory bug, Orius niger (Hem.: Anthocoridae) to Tetranychus urticae (Acari: Tetranychidae) on cucumber leaves treated or untreated by Beauveria bassiana

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    Olfactory experiments were performed to study the predation behavior of Orius niger Wolff (Hemiptera: Anthocoridae) on the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) in presence or absence of Beauveria bassiana (Bals.). The experiments were carried out with six day old female bugs by recording the predator direction towards each of the Y-tube olfactometer arms and through three dependent replicates consisted of 15 replicates each. The predatory bug showed a significant preference towards the odors related to infested cucumber leaves by T. urticae in the absence of fungus and when the predator received odors related to T. urticae infested leaves v.s. B.bassiana fungus treated, spider mite infested leaves (72 hours). There was no significant difference in the predator olfactory experiment when the alternative arms consisted of treated v.s. untreated spider mite infested cucumber leaves (0, 24 and 48 hours after treatment). The results showed the capacity of the predatory bug to recognize the patches infected by B.bassiana fungus and successfully avoiding it

    Transmission possibility of the fungus Beauveria bassiana KCF102 by mating behavior between Sunn pest, Eurygaster integriceps (Hem.: Scutelleridae) adults

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    Horizontal transmission of an isolate of the etomopathogenic fungus, Beauveria bassiana KCF102, was examined by allowing inoculated Eurygaster integriceps Put. adults to mate with non-inoculated ones. In case of susceptibility to B. bassiana, there was no significant difference between the males and females. However, there was significant difference among treatments for mortality of non-inoculated adults. It meant horizontal transmission could be happened between the inoculated and non-inoculated adults. Recording no significant difference among the treatments of the inoculated males + non-inoculated males and treatment with inoculated females + non-inoculated males revealed that this kind of horizontal transmission was not merely due to the mating behavior, given that the same transmission could be existed between inoculated and non-inoculated males or between those of female adults. There was significant difference for mortality percentage of adults among the five body-part treatments, ranging from 16.6 to 48.9, with the highest mortality for total body treatment and the lowest one for the pronotum

    A laboratory investigation on virulence of Metarhizium anisopliae on Thrips tabaci (Thys.: Thripidae) and its predator, Orius albidipennis (Hem.: Anthocoridae)

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    In the present study, virulence of three isolates of Metarhizium anisopliae (Ascomycota, Clavicipitaceae) were evaluated on the second instar larvae of the onion thrips, Thrips tabaci Lindman by using spray potter tower at six conidial concentrations of isolates (103-108 conidia/ml) with Thrips Entomopathogenic Bioassay System (TEBS) method. Causing the highest total mortality rate on thrips larvae and having the lowest LC50 value (2.3 Ã 104 conidia/ml), M. anisopliae EUT118 was selected as the highest virulent isolate. Afterwards, the susceptibility of female adults and 5th nymphs of Orius albidipennis (Reuter) was tested against this isolate of M. anisopliae without attendance of host. Results indicated that two stages of predator; female adults and 5th instar nymphs had similarly low susceptibilities to fungal infection. In general, our results revealed that the anthocorid predator, O. albidipennis was less affected by this isolate of fungus. As a result, these two biocontrol agents could be used both together in control programs of T. tabaci in greenhouses

    Report of Eristalis similis (Diptera: Syrphidae) from Iran

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    During a survey conducted on Syrphidae fauna in Guilan province (Masuleh & Lakan) in August 2006, some species of the genus Eristalis Latreille were collected and identified, of which E. similis (Fallen) is newly reported from Iran. The identification was confirmed by Heikki Hippa, Swedish Musem of Natural History

    Evaluation of the effect of MbNPV on cabbage moth, Plutella xylostella (Lep.: Plutellidae), in laboratory conditions

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    Cabbage moth, Plutella xylostella L., is the most important pest in cabbage and canola cultures in Iran. Nuclear polyhedrosis viruses are known as important natural enemies of this pest. Because of economic importance of cabbage moth and the necessity of its control, MbNPV (Baculoviridae) was chosen to evaluate its effect on cabbage moth. Experimental data showed that the virus had high virulence and could be considered as the important agent for the control of this insect. In infestation of egg surfaces with 1 Ã 105 PIB/ml of MbNPV, all of larvae died three days after hatching. The LC50 value for the second instar larvae of cabbage moth was calculated 11.99 PIB/mm2. The LT50 values for the same larvae with 19.5 and 47.86 PIB/mm2 doses of MbNPV were 7.16 and 6.11 days, respectively. Mean percentages of mortality with 47.86 PIB/mm2 for 2nd, 3rd and 4th instar larvae were 74.44, 42.78 and 11.11, respectively

    Report of the genus Parhelophilus Grischner (Dip.: Syrphidae) from Iran

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    The species, Pharhelophilus versicolor (Fabricius), was collected during the study of the syrphid flies (Dip.: Syrphidae) fauna in Sangachin and Shijan, Guilan province. Further confirmation was made by Menno Reemer. The genus and species is newly recorded from Iran

    Study on potential of some solid natural substances in production of Beauveria bassiana (Ascomycota, Cordycipitaceae) conidia

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    In this study, two fungus isolates, Beauveria bassiana EUT105 and B. bassiana EUT116, were evaluated for production of aerial conidia on wheat, wheat flour, wheat bran, rice flour, rice bran, rice paddy, millet and corn flour using two phasic liquid-solid system. Data analysis showed that there are significant differences among treatments (simple media) in both isolates. In B. bassiana EUT105, the maximum and minimum productions were achieved on wheat bran, 2.3 Ã 1010 conidia/g and on rice paddy, 1.5 Ã 109 conidia/g of medium, respectively. In B. bassiana EUT116, wheat bran with 6.1 Ã 109 conidia/g and millet with 8 Ã 108 conidia/g had the maximum and minimum productions, respectively. Effect of adding nutritional complementary compounds to the growth media was significant in increasing of conidial yield. Related results showed that adding permeate increased the production but molasses did not it in comparison with control in both isolates. Wheat bran plus permeate had the maximum production, 5 Ã 1010 and 4.6 Ã 1010 conidia/g in B. bassiana EUT105 and EUT116, respectively and minimum production was obtained with rice flour plus molasses, 1.5 Ã 108 and 6 Ã 108 conidia/g in B. bassiana EUT105 and EUT116, respectively

    Influence of permanent night work on the circadian rhythm of blood pressure

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    Abstract. Night workers exercise their labours activities and rest in contrary schedules to the chronobiological standards. This inversion leads the body to several adaptations, including changes in the circadian rhythm of blood pressure (BP). Objectives: To evaluate the BP in individuals who perform work at night, in order to objectively detail the BP circadian rhythm adaptations infixed night workers. Methods: A cross-sectional study enrolling 23 fixed night workers, both genders, was performed, with 24h BP measured with ambulatory blood pressure monitoring (ABPM) during a normal working day. Risk factors, anthropometric and lifestyle information were collected using a standard questionnaire. Results: Ambulatory BP demonstrated a pattern of adaptation to the sleep/activity cycle in all participants. BP dropped during the sleeping period (mean drop: -11.35±6.85) and was higher during the awakening period, reaching the highest results and greater BP variability during the working period. The chronobiological adaptation of the 24h BP was not dependent on sociodemographic or clinical characteristics. In addition, age, male gender, obesity, and those working less time were associated with higher BP mean values. Conclu-sions: The circadian rhythm of BP follows the working circadian profile of the individual.info:eu-repo/semantics/publishedVersio
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