Comparative Bioefficacy of Different Citrus Peel Extracts as Grain Protectant Against Callosobruchus chinensis, Trogoderma granarium and Tribolium castaneum
2 Abstract: Efficacy of essential oils extracted from peel of various citrus species; Citrus reticulata, Citrus sinensis, Citrus paradisi and Citrus grandis were determined against the adults of Callosobruchus chinensis and Tribolium castaneum as well as against the larvae of Trogoderma granarium in order to find out safe alternatives of high toxics. Four concentrations of each oil; 2%, 4%, 6% and 8% were assayed for their insecticidal activity after exposure durations of 24, 48, 120 and 168 h. The results revealed that the essential oil vapors showed variable toxicity to insects depending on concentration and exposure duration. Efficacy increased as the exposure time and concentration were increased for all insects. All the oils were found to be very successful against adults of C. chinensis. Out of which, the oil of C. sinensis was the best against C. chinensis even at lower concentrations; LD , LD and LD values were 3.49%, 4.70% and 5.91% after 72-h 50 70 90
Effects of Some Plant Extracts and Bensultap on Trichoferus griseus (Fabricius, 1792) (Coleoptera: Cerambycidae)
2 Abstract: Aqueous extracts prepared from seven plant species, Cyclamen mirabile Hildebr., 1906 (Pirumilaceae), Fritillaria bithynica Baker, 1874 (Liliaceae), Juglans regia L., 1753 (Juglandaceae), Muscari neglectum Guss., 1842 (Liliaceae), Nicotiana tabacum L., 1753 (Solaneceae), Sternbergia candida Mathew and Baytop, 1979 (Amaryllidaceae), Urginea maritima L., 1872 (Liliaceae) were tested for their insecticidal activity against Trichoferus griseus F. (Coleoptera: Cerambycidae) on Pinus brutia L. in the laboratory in 2007. Insecticidal effects of aqueous plant extracts were compared to the application of an insecticide (Bensultap, Bancol 50 WP) and synthetic chemical preservation (chromated copper arsenate, CCA, Tanalith C), which is widely used as a positive control. The effects of those materials on larvae were also analyzed. The bolts have been impregnated with seven aqueous plant extracts and Bensultap and CCA by using a vacuum desicator. Then, larvae of T. griseus were placed on the treated and non-treated bolts. Bensultap was the most effective and more significant in reducing the number of larvae in all the trials when compared to the other treatments. The effects of six plant extracts on the larvae were statistically similar to each other except for U. maritima. The effects of Tanalith C and U.maritima were statistically similar to control. Bensultap would be a welcome addition for the control of wood pests. Aqueous extracts of the six plant species exhibited insecticidal activity are potential candidates as new organic insecticides.
D'une application pratique des indices bio-météorologiques
Abstract The purpose of the author is to determine statistically in what part of Switzerland maize could be cultivated with certain chance of rentability. The author gives first the method he used for determining the biometeorological index of four species of maize which were selected by the Swiss agronomical research stations. He has considered two possibilities for the growing period: ( a ) raising-ripening (l'approche globale); ( b ) raising-flowering, flowering-ripening (l'approche fractionee). From the biometeorological index, he calculated retrospectively the ripening time of these four species in the years 1901–1965. Assuming a priori that maize should be harvested before October 15th at the latest, he calculated, for a number of meteorological stations, the relative number of years when such conditions were fulfilled. Dividing the country in regions of similar mesoclimates and sorting these stations per region, it is possible to average the maximum altitude where maize can ripen at least 7, 8, 9 and 10 times within 10 years. Finally, taking into account the exposure and ground slope, he draws maps of the theoretically possible extension area, which maps are more reliable and detailed than the ones derived from actual means.