การเปรียบเทียบน้ำหมักหญ้าบางพันธุ์ที่มีในท้องถิ่นเพื่อการชักนำการวางไข่ของยุงรำคาญ Culex quinquefasciatus Say (Diptera : Culicidae) / อดุลย์ ฉุงน้อย = Comparative study on oviposition attractants of some exotic grass infusions to Culex quinquefasciatus Say (Dipterra : Culicidae) / Adul Choungnoi
Oviposition traps have proven to be effective for monitoring a number of population, particularly as they attract predominantly gravid females. The grass infusions are cheap and easy to produce and depending on the particular infusion used the traps are also population selective which limits processing time. Several man made traps are now available for use with attractive infusion baits. The purpose of this study was to compare the different kind of fermented grass infusions which attract and stimulate oviposition by the mosquito Culex quinquefasciatus Say Six fermented grass infusions of Brachiaria mutica, Panicum repens, Chloris barbata, Dactyloctenium aegyptium, Cynodon dactylon and Pennisetum purpureum were fermented aerobically for 12 days. These fermented grass infusions were used in oviposition experiments on gravid Cx. quinquefasciatus. The infusions were exposed to gravids for 24 hrs and the egg rafts counted. The best attractant to induce oviposition was extracted by ether. The fraction from Acid/Base Extraction was separated by Flash Chromatography. The fractions from Flash Chromatography were used in oviposition experiments on gravid Cx. quinquefasciatus. It was found that the oviposition attractant from fresh grass infusions induced oviposion more than fermented dried grass, BY+LH and distilled water were significantly lower (p< 0.05) The number of egg rafts deposited was independent of grass types significantly. The number of egg rafts from weak acid/neutral fraction were significantly lower (P<0.05) than the control. For PG-2N-4 fraction which extracted from weak acid/neutral fraction were significantly lower (p<0.05) in the number of egg rafts as compared with the control.
