Character Analysis Of The Selection Of Meadow Moth, Loxostege Sticticalis To Host Plant

Meadow moth, Loxostege sticticalis L.(Lepidoptera: Pyralidae) is one ofworldwide insect pests which often occurs in the North China, Northeast andNorthwest of China. It feeds upon a wide range of crops (approximately35Families，nearly200species of host plants) including many economic crops infarming and stockbreeding. Great loss has been recorded due to the damage byLoxostege sticticalis L. Based on long-term co-evolution with its host plants,Loxostege sticticalis L. feeds and oviposits on suitable host plants once or severaltimes during its life cycle. Different host plants also influence its growth,development and population growth. The selection of Loxostege sticticalis L todifferent host plant was studied in order to clarifying the mechanisms of theco-evolution of Loxostege sticticalis L with host plant and putting forward effectiveand safe measures to control it.The co-evolution of Loxostege sticticalis L with host plants was clarified fromplant volatile collection and identification, its growth and development when thelarvae feeding with different plants, and its ovposition selection. Moreover, thefunction of double mutant OBP1was verified by site-directed mutagenesis andbinding experiments, as well as the function-site of LstiGOBP1was investigated. Itprovides a new pathway to study the co-evolution between insect pest and host plantat a molecular level. The primary results are as follows: (1) Their developmental durations were obviously different from each otherwhen the larvae feeding on different host plants. They could complete the life cyclefeeding on Melilotus suaveolens Ledeb, Medicago sativa Linnor Chenopodium albumLinn, but died within3d after feeding on Astragalus adsurgens Pall and Elymussibiricus Linn. The female moths laid more eggs on Melilotus suaveolens Ledeb,Medicago sativa Linnand Chenopodium album Linn than on the other plants, and laidleast eggs on Astragalus adsurgens Pall and Elymus sibiricus Linn.(2) The volatiles of7host plant (Melilotus suaveolens Ledeb．, Medicago sativaLinn, Lespedeza bicolor Turcz, Astragalus adsurgens Pall., Festuca elata Keng,Lolium and Elymus sibiricus Linn were collected by headspace absorption methodand analyzed by GC-MS.8compounds were identified from Melilotus suaveolensLedeb and Astragalus adsurgens Pall. samples.7compounds were identified fromLolium and Medicago sativa Linn. samples.9compounds were identified fromElymus sibiricus Linn samples.11compounds were identified from Festuca elataKeng Linn samples.13compounds were identified from11compounds wereidentified from Festuca elata Keng Linn samples. Linn samples.(3) Compared with unmutated protein, associativities of mutant protein with sexpheromone, camphene,1-hexanol, heptanol, olefin aldehyde, cinnamyl aldehyde andbenzaldehyde were decreased significantly. It proved that the function site ofLstiGOBP1may be two mutated sites.