| Apolygus lucorum is a significant kind of pest in the Huanghe Valley and Longriver Valley of China. Besides damaging cotton, the pest seriously damage the other crops such as jujube, grape, cherry, peach, apple, tea plant, poplar and potato. The loss can reach 20-30% of the above crop planted in the common years, and can exceed 50% in some years. Moreover, Apolygus lucorum are very restricted to drugs, so the disaster areas need to spread pesticide for more than 10 times, which killed the pests but at the same time cause potential damage to the environment and human health.Considering there were no effective ways to prevent the extensive outbreak of Apolygus lucorum, we came up with the idea to use sex pheromone to monitor and control Apolygus lucorum. In this research we applied the methods of GC, GC-MS, EAG, GC-EAG and field tests to find out how chemical communication mechanism of Apolygus lucorum works and explored their dynamic change regulation. All of these will offer theoretical support and experimental basis for the prevention and treatment to Apolygus lucorum. The main results are showed as follows:1, Extraction and identification of the sex pheromone from Apolygus lucorumAccording to GC-MS, the female sex pheromone from Apolygus lucorum mainly consists of 4-oxo-(E)-2-hexenal, hexylbutyrate, trans-2-hexenylbutyrate, their contents were 21.75±2.04μg, 1.42±0.56μg , 23.74±1.89μg respectively。The key components of male sex pheromone were the same compared with the female except their proportion, Which were 13.68±3.32μg,27.73±6.54μg and 3.84±1.67μg respectively. The ratio of hexylbutyrate and Trans-2-hexenylbutyrate were totally opposite between the male and female pest, so hexylbutyrate was anti-sex pheromone of the male.2, Releasing pattern of sex pheromoneThe amount of sex pheromone remained unchanging during the first two hours of the dark period; then 4-oxo-(E)-2-hexenaland, trans-2-hexenylbutyrate decreased rapidly until the fifth hour reach to the bottom amount. This phenomenon show that the releasing peaks of the pests'sex pheromone may probably be between the second to the forth hour .During the light period the sex pheromone in female pest gradually increased, until the tenth hour the amount 4-oxo-(E)-2-hexenal and trans-2-hexenyl butyrate reached to a very high level. This illustrated that Apolygus lucorum don't release their sex pheromone immediately after producing .The pests were kept the sex pheromone in body and then released until mating call in dark period. The content of hexylbutyrate abstracts from female was really low, averagely lower than 0.5μg, which also had no obvious relationship with dark-light period.3. Synthesis and bio-activities of sex pheromoneWe synthesized the three main components abstracted from Apolygus lucorum: 4-oxo-(E)-2-hexenal,hexylbutyrate,and trans-2-hexenylbutyrate by using chemical methods, and verified their saturation through HNMR and MS. Then their activities were preliminary tested with EAG and GC-EAD. All synthetic compounds can cause antennal reaction and hexylbutyrate had the strongest EAG activity which reached 6.36±0.54mV. And the activity of the binary and the ternary components was better than the single component. However, when doing behavior test in Y-tube olfactometer, any of the components can't obviously attract the male.4, Field test and the optimization of formulationThe synthetic sex pheromones were used to make lures in field test. The result showed that the single component was unstable and can only attract small number of the male Apolygus lucorum. One the other hand, the components of 4-oxo-(E)-2-hexenal and trans-2-hexenylbutyrate within a certain range can get good results. Through optimization test we noted that the best ratio of 4-oxo-(E)-2-hexenal and trans-2-hexenylbutyrate was 900:600. Hexylbutyrate had no contribution to attraction but had inhibitory action to the male pests.5, Research of anti-sex pheromoneHexylbutyrate can apparently restrain the sex pheromone's attract to the male Apolygus lucorum and had strong activity. When it was added to the lures consisting of 4-oxo-(E)-2-hexenal and trans-2-hexenylbutyrate with different amounts, we could easily find that with increasing of hexylbutyrate, the number of attracted male pests decreased obviously. When the content of hexylbutyrate reaching to 10%, the sex pheromone almost turned inactive. After mating, the male bugs would inject hexylbutyrate into the female or tempted the female to produce hexylbutyrate, which would disturb other female's orientation and prevent the second mating.6, Preliminary study of sex pheromone of other bugUsing the same extraction and identification method we study the sex pheromone of Adelphocoris suturalis, Adelphocoris fasciaticollis, and Adelphocoris lineolatus. Their main components were similarly 4-oxo-(E)-2-hexenal,hexylbutyrate and trans-2-hexenylbutyrate. However, compared with Apolygus lucorum, the content of 4-oxo-(E)-2-hexenal of the above three bugs was lower. In female Adelphocoris suturalis, the main component was Hexylbutyrate and the main components in female Adelphocoris lineolatus was trans-2-hexenylbutyrate.This research firstly verified and analyzed the main components of sex pheromone of Apolygus lucorum and their accurate ratio. At the same time we found out the presence of anti-sex pheromone, and verified its disturbance to the mating behavior. Through EAG reaction and field attract test we got the best formulation of tempts core, which can be directly used in the field attract. This research has enriched the knowledge of sex pheromone of insects, and will offer a new non-toxic controlling way of high efficiency, non-poisons, and non-environment pollutions.
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