Research On Acoustic And Olfation Communications Of Some Orthoptera And Diptera Species

The variety of insect species forms our colourful world, which is a results of the revolution of hundreds of millions years, different insects also evolved their own method of communicating with outside environment. The most important communication methods of insects are acoustic signals and olfactions, which were also the hot research area in insects during past decade. Different species have their specific communication method, thus, this study mainly focus on the insect in Orthoptera and Diptera. The songs traits, songs generators, acoustic evolutions, songs applications were studied among some species in super family Tettigoniidae and Gryllidae, moreover, the odorant receptors in Anopheles gambia and Culex quinquefasciatus were expressed in UAS-GAL4system and Xenopus laevis oocytes system. All the results will give us a better understand of insect communications and some acoustic, odorant relative beviours such as mating, host seeking, foraging and oviposition, and provide us some theoretically cues in potential strategy in pest management and control.By the methods of acoustic analysis’, molecular biology, electric physiology, and heterogeneous expression, the obtained results were as below:1.In the study of Orthoptera acoustic communications,9species of katydids and3species of crickets were studied on their calling songs, which included the frequency domain and time domain characters of their songs, and the micro structure of their song generators, the results showed that all the characters had a high stability within species and a high variety between species. The pulse number in pulse groups is from3to series depand on the tested species, and frequency distribution range is from3.78±0.01kHz to35.3±0.3kHz, generally speaking, the frequency of songs in katydids were higher than crickets, and the frequency was inverse correlated with their body length, the calling songs of cricket species were pure tone, and the katydids were broad band signals or broad band with some pure tone structures, The frequency distributions in genus Metrioptera were higher than others.2. The study of stridulatory files showed there were great differences in the sturcuture between katydids and crickets species we studied, cricket’s stridulatory files were thin, orderliness and all chip form like which were compared with katydid’s thick, irregular and bar form like, it also showed a high varity between species. Based on these acoustic relative characters, a phylogenetic analysis was performed to show the relationship between these species, results showed great similarity to convetional methods such as morphology and molecular characters, suggested that the "pure acoustic relative character could be used in the phylogenetic studies in acoustic insects.3. Different ecotype also influenced the acoustic characters of insects, in Metrioptera engelhardti, we measured and analized the calling songs of both macropterous and brachypterous forms of this species, the results showed that macropterous forms of M. engelhardti had a higher duration of pulses, a higher duration of pulse groups and a shorter interval between pulses compared with brachypterous forms, stridulatory files observation showed there is no significant differences between the two, except the intervals between files. All the results indicated that macropterous forms of M. engelhardti was not compeletly disadvantage in mating behavour as previous studies showed, they appears a more "effort songs" than their macropterous relatives, which showed a compensation in acoustic characters. The changes in the acoustic characters of macropterous were benefit to the female mating choice by increasing the atrractions of their calling songs. At last, a phylogenetic analysis was perform between the two types, results showed there were indeed some differences between these two type of insect at molecular level, which indicated the population density at most, was not the only cause in the determation of insects wing type.4. In the application studies aspect, we recorded and analyzed calling samples in three different density levels of Asian migratory locust Locusta migratoria migratoria. The results showed that the songs of L. migratoria magratoria had a very stable acoustic feature in time domains, then we used duration of pulse as a tool to identify and counted the pulse numbers in order to identify the population size level. After removing the background noises, an automatic density classification and monitoring system was established based on BP neural network. The field sample test showed that the accuracy of the density level recognition can reach96.67%.The results indicated that the calling songs of insects could be an effective character to distinguish population density level of locust plagues and it could be potentially used as a green and environmental protection solution in monitoring the dynamics of locust plagues.5. The studies on insect olfactory communications were mainly focus on Anopheles gambiae and Culex quinquefasciatus, and mainly focus on their Ordorant receptors. The cDNA of Anopheles gambiae were sythesised and5ordrant receptors were cloned, they were AgOr8、AgOr16、AgOr30、AgOr48and AgOr65, then they were subcloned to pUAST plasmid in order to construct transgenetic fruit flies, colony PCR, doube digest and sequencing results showed the recombination plasmid were successfully made. Then the plasmid were send to injection, crossing and screening, finally we get5strains of flies which were UAS-AgOr8, UAS-AgOr16, UAS-AgOr30, UAS-AgOr48and UAS-AgOr65, by crossing with Orco-Ga14strains, we got expressing of AgOrs in Drosophila melanogaster, EAG results showed that these stains had higher attena response their parents, which indicated the successfully expressing of AgOrs in Drosophila melanogaster, finally we make a discussion on these stumilates and function of these AgOrs.6. In Culex quinquefasciatus, we sythesised cRNA of a odorant receptor which named CqOR99, then we expressing it in Xenopus laevis oocytes, two-electrode voltage-clamp recording showed that this OR was highly response to4-methylphenol and4-ethylphenol, the biological function of these two stumilates and this OR need more experiments to be proved.Songs traits, acoustic organs, acoustic evolutions and applications of songs were studied among13species in Orthoptera, moreover,6odorant receptors were cloned and expressed in UAS-GAL4system and Xenopus laevis oocytes. At last we made a brief discussion on the revolution and comparison of these two communication methods. All the results can give us a better understand of the communications in insect and provide some theoretical support for potential strategy in pest control.