Research Of Promoted Trapping Effect On Liposcelis Bostrychophila Based On The Radial Channel And Cup Trap

Timely detection of stored grain insect pests is important for early control and avoiding damage to stored grain.The use of information collection in conjunction with trapping equipment can achieve online detection of the stored grain insect pests.In the past,research on insect detection technologies in stored grain mainly focused on beetles and moths.However,the regulations for detecting L.bostrychophila are inadequate currently.Based on the national patent "A device for capturing and real-time monitoring of L.bostrychophila in stored grain using the radial channel and cup trap",an insect surface trapping device was developed.The monitoring effects on L.bostrychophila were satisfying,and online monitoring of stored grain pests can be achieved.Adding food or light to the radial channel and cup trap-based trapping device is expected to increase its efficiency in trapping psocids.The trap device based on the radial channel and cup trap was set in the simulated grain bulk test device at 20,24,and 28°C.The numbers of L.bostrychophila trapped in the radial channel and cup trap were measured when the adult density was different.The number of L.bostrychophila trapped in the radial channel and cup trap after adding 7 kinds of flour was also determined,respectively.The number of pests trapped was determined after setting 4 kinds of lights in the traps.Under the conditions of yeast powder and a 351 nm light,the number of pests trapped by the trap was tested at different densities for L.bostrychophila.The main results are as follows:(1)At 28°C,the time when L.bostrychophila first appeared in the radial channel and cup trap after infecting different adult densities of L.bostrychophila in grain bulks of 25,50,100,200,250,400,500,1000,and 2000 adults/kg was 3,5,1,1,1,1,1,and 1 d,respectively.The corresponding numbers of trapped psocids were 1,1,1,3,3,6,7,15,and 27 adults,and then the numbers of trapped psocids increased daily at the corresponding density until reaching the peak of 1,1,5,7,7,7,7,and 8 d(the number of the trapped psocids no longer increased per day).The corresponding peaks were 0,1,3,6,8,14,16,35,and 65 adults.The total numbers of psocids trapped by the traps during the test period under different density settings were 7,16,38,82,98,185,204,442 and 923 adults,respectively.At 20°C and 24°C,the time when psocids first appeared in the radial channel and cup trap is delayed,and the daily trapping numbers are correspondingly reduced.At the same temperature,as the density increases,the time to attract booklice gradually advances and the trapping quantity significantly increases;at the same density,as the temperature rises,the time to trap psocids gradually advances and the trapping quantity significantly increases.(2)At 28°C,after adding wheat flour,corn flour,rice flour,yeast powder,moldy corn flour,moldy wheat flour,and moldy rice flour to the radial channel and cup at a simulated density of 1,000 adults/kg,the total number of trapped psocids during the test period was 479,460,451,827,662,605,and 604 adults,respectively.At 20°C and 24°C,the time when psocids first appeared in the radial channel and cup trap is delayed,and the daily trapping numbers are correspondingly reduced.The order of the seven types of food in increasing the trapping effect of the trap at all test temperatures was as follows: yeast powder > moldy wheat flour > moldy corn flour >moldy rice flour > wheat flour > corn flour > rice flour.Among the seven types of food used in the experiment,yeast powder had the best attracting effect on L.bostrychophila.The volatile organic chemicals of the tested food materials were determined by gas chromatography–mass spectrometry(GC–MS).The results showed the numbers of volatile substances analyzed from 7 kinds of flour were 17,24,20,20,23,and 25,respectively.For preliminary purposes,the high levels of linalool,isoamyl alcohol,ethyl 2-methylbutyrate,and n-hexyl alcohol may be related to the significant attracting effect.At 28°C,the time when L.bostrychophila first appeared in the radial channel and cup trap after adding yeast powder after infecting different adult densities of L.bostrychophila in grain bulks of 25,50,100,200,250,400,500,1000,and 2000adults/kg was 2,1,1,1,1,1,1,and 1 d,respectively.and then the numbers of trapped psocids increased daily at the corresponding density until reaching the peak of 1,8,8,7,6,6,7,and 8 d.The total numbers of psocids trapped by the traps during the test period under different density settings were 10,25,59,141,165,332,365,and 826 adults,respectively.At 20°C and 24°C,the time when psocids first appeared in the radial channel and cup trap is delayed,and the daily trapping numbers are correspondingly reduced.(3)At 28°C,after setting light of 351,432,531,and 621 nm in the trap,at a simulated density of 1,000 adults/kg,the total number of the trapped psocids during the test period were 1027,713,673,and 694 adults,respectively.At 20°C and 24°C,the time when psocids first appeared in the radial channel and cup trap is delayed,and the daily trapping numbers are correspondingly reduced.The order of the four types of light in increasing the trapping effect of the trap at all test temperatures was as follows: 351 nm > 432 nm > 531 nm > 621 nm Among the four types of light used in the experiment,light of 351 nm had the best attracting effect on L.bostrychophila.At 28°C,the time of initial appearance and peak daily trapping number of L.bostrychophila in the radial channel and cup equipped with 351 nm light after infecting different adult densities of L.bostrychophila in grain bulks of 25,50,100,200,250,400,500,1000,and 2000 adults/kg was 1 d.The corresponding peaks were1,2,6,15,18,37,40,and 85 adults.The daily trapping numbers in the grain bulk of1000 adults/kg declined from the 7th day until the end of the test.The total numbers of psocids trapped by the traps during the test period under different density settings were 15,36,88,205,256,483,582,and 1,027 adults,respectively.At 20°C and 24°C,the time when psocids first appeared in the radial channel and cup trap is delayed,and the daily trapping numbers are correspondingly reduced.