Research Of Effect And Mechanism Of Olfaction On Prey Locating Of Wolf Spider

As an important predatory natural enemy of agricultural ecosystem,wolf spider are widely distributed in the world,they also have lots of excellent properties of controlling pest.Among each feeling mode of wolf spider,the sense of smell plays a significant role.These paper was carried out to study the smell mechanism of wolf spider in the process of choosing and locating prey,which conclude behavior and electrophysiological testing.Living Aphis craccivora were selected to be soaked in the n-hexane solvent,and made them stand for 30 minutes to evaporate more n-hexane solvent,which could concentrate sample species.Wolf spider's reaction to Aphis craccivora body surface volatiles was investigated by Y-tube olfactometer.Then scanning electron microscopy was used to scan the hair sensors(tactile hairs,auditory hairs,chemosensory hairs)of wolf spider.Finally,through Gas Chromatography-Electroantennographic Detection(GC-EAD)to test the volatiles of Aphis craccivora body surface to wolf spider carry on electric potential reaction to respond a measurement.The results are as follows:1.Three types of sensory hairs on the body surface of Pardosa pseudoannulata,which belongs to Lycosoidea,were found by scanning electron microscopy.They conclude tactile hairs,auditory hairs and chemosensory hairs.They are mainly distributed in the tarsus and tibia of walking legs and also in the pedipalps.According to the number of hairs from greatest to least: tactile hairs?chemosensory hairs?auditory hairs;According to the length of hairs from longest to shortest: auditory hairs?tactile hairs?chemosensory hairs;According to the thickness of hairs from thickest to thinnest: tactile hairs?chemosensory hairs?auditory hairs;According to the shape bending of hairs from the curved to straight: chemosensory hairs?tactile hair.The degree of shape bending of auditory hairs varies in different distribution.According to the size of sensory hair follicle's gap from largest to smallest: auditory hairs?chemosensory hairs?tactile hairs.2.Behavior test revealed that in the distance of 8 centimeters,the average choosing rate of female and male wolf spiders to Aphis craccivora body surface volatiles and n-hexane solvent displayed highly significant differences(p<0.01).In the distance of 15 centimeters,the average choosing rate of female and male wolf spiders to Aphis craccivora body surface volatiles and n-hexane solvent displayed significant differences(p<0.05).Both male and female wolf spider exhibited lower significant difference to two kinds of odors compared to prior testing.In the distance of 22 centimeters,the average choosing rate of female and male wolf spiders to Aphis craccivora body surface volatiles and n-hexane solvent displayed no significant difference(p>0.05).The results revealed that the distance of odor source has a certain effect on wolf spider choosing and locating prey.Attraction of Aphis craccivor's body surface volatiles to wolf spiders decreases correspondingly with an increase of the distance odor source.It follows that there are volatiles released from Aphis craccivor's body surface that attract male and female wolf spiders,the wolf spiders' sensitivity of smell almost defunctionalized in the distance of 22 centimeters.And,there was no significant sexual differential in choosing rate of wolf spiders between female and male to Aphis craccivor's body surface volatiles in the scope of testing distance(p>0.05).3.Based on the electron microscopy scanning observation,wolf spider's first legs were chosen to do electrophysiological test,which was cut off from the point on femora where was closed to tibia.We also made a cut in the end of distitarsus,which was designed to make electricity pass.Until the EAD line was stable,2?l extract of Aphis craccivor's body surface was infected into GC equipment to start the test.The research of GC-EAD expressed that both female and male wolf spider reacted to two kinds of volatile components extracted from Aphis craccivora body surface.To further strengthen the efficiency of wolf spider controlling pest,this paper has guiding significance on researching the effect and mechanism of olfaction in the process of wolf spider choosing and locating prey.It also riches content of arachnology.