Study On Antennal Sensilla And Aggregation Pheromone Of Locusta Migratoria Tibetensis(Chen)

Locusta migratoria tibetensis (Chen) membership Orthoptera, Acridoidea, Oedipo-dodae,Locusta,which was a new subspecies made in1963by Chen Yong-lin.It damaged maize,highland barley,wheat and other cereal crops and pasture,and caused serious economic losses to agriculture and animal husbandry. In China, studying of occurrence and control for L. migratoria tibetensis (Chen) was not very mature, the research only focuses on the description of morphological, biological and ecological characteristics. In addition, few reported about L. migratoria tibetensis (Chen).Studying of behavioral responses and electrophysiological responses for aggregation pheromone which in L. migratoria tibetensis (Chen)’s fecal extract, chemical components of aggregation pheromone,and observation of antennal sensilla of L. migratoria tibetensis(Chen)with scanning electron microscope,the following findings.1. L. migratoria tibetensis (Chen) to its aggregation pheromone response in fecesThe results of responses of L. migratoria tibetensis (Chen) to its aggregation pheromone in feces showed that the biological activity of aggregation pheromone in the crude extracts of the feces increases by instar and density increased.The electrophysiological responses of L. migratoria tibetensis (Chen) to its aggregation pheromone in feces showed that aggregation pheromone trapping activity in the gregarious phase crude extracts of feces was better than in the solitary phase. The trapping activity of four different solvent extraction told that alcohol was best, acetone followed by, then methylene chloride, hexane and ethanol ultrasonic crude extract of low trapping activity, and behavioral responses were consistent with electrical activity.In the provided six different types of instars and gender L. migratoria tibetensis (Chen), the behavioral responses and electrophysiological responses of the gregarious phase was better than the solitary phase. In the same phase test insects, female adults and4th instar nymphs nymphs had non-obvious regularity for reactivity of behavioral responses to different sources feces, but female adults’was higher, and male adults’was highest.2. Studying of aggregation pheromone components for L. migratoria tibetensis (Chen)The composition of aggregation pheromone in alcohol extract of L. migratoria tibetensis (Chen) feces showed the following characteristics:adults was more than nymphs, and females up; gregarious phase and solitary phase had no significant difference; gregarious and solitary-phase adult (♀,♂) and nymphs had11kinds of material with Locusta migratoria manilensis (Meyen), but the proportion of different. Phenol,2,2’-methylenebis[6-(1,1-dimethylethyl)-4-methyl and cholestan-3-ol,2-methylene-,(3β,5α)-were only found in volatiles of feces of L. migratoria tibetensis (Chen). Former had higher levels of certain behavioral responses, but the electrophysiological response was not obvious, the latter in different types of instars and gender L. migratoria tibetensis (Chen) fecal crude extracts have been found, and the content was higher, but whether aggregation pheromone components of L. migratoria tibetensis (Chen) fecal volatiles, remains to be further study to prove.3. Response to aggregation pheromone of elemental for L. migratoria tibetensis (Chen)The six provided test insects had a chemotactic responses to cyclohexanol,2,5-dimethylpyrazine, nonanal, benzaldehyde, α,β-dimethyl ethanol and phenol,2,2’-methylenebis(4-methyl-6-tert-butyl)-within a certain range of concentrations. No significant difference compared among six types of test insects for the behavioral response between the tested several single qualitative, behavioral responses of solitary insects was slightly higher than the gregarious insects. With the change of the concentration change, the trend of their behavioral response was more consistent, that was chemotactic response no significant difference in substance concentration in the strongest. Within the concentration range of0-4μl/ml, L. migratoria tibetensis (Chen) had certain electrophysiological responses to the tested several single qualitative, and showing a certain trend; from six kinds of insects electrophysiological responses so far, solitary insects compared with more gregarious phase, and male’s electrophysiological values was higher than female’s, solitary adult electrophysiologi-cal response was significantly higher than the other four kinds of insects.4. Studying of antennal sensilla of L. migratoria tibetensis (Chen)Five types of sensilla were found on antennae of L. migratoria tibetensis (Chen): sensilla trichodea,sensilla chaetica,sensilla coeloclnica,sensilla basiconica and sensilla cavity. Nymphs had smaller and fewer sensilla than adults, and also differed in the distributi-on of sensilla.Male adults had no significant difference in shape.type and distribution with female adults, but the number of antennal sensilla of former was more slightly. but gregarious locusts had fewer sensilla than solitary locusts, meanwhile, solitary phase was more than gregarious phase,too.The distribution of antennal sensilla was fewer on scape and pedicel, and more on flagellum. And gradually increased at both ends of antennae (end and the base). The distribution of each sub-section showed that the number of antennal sensilla at back and inner side was significantly less than the ventral surface of the outer side, and the number of the inner side of the sensor at least. Then solitary locusts had more antennal sensilla than gregarious phase.