Influence Of Association Between Repellents And Attractants On The Behavior And Antenna Electrophysiology Of Mosquitoes

As one of the main sanitary insect pests, mosquitoes not only suck blood and harasspeople’s peace, but also carry of various diseases. Therefore, mosquitoes control has al-ways received widely attention. Mosquito repellent is one of the important means to con-trol mosquitoes. However, the function mechanism of repellent is still unclear. The mo-lecular interactions between repellent and human attractant may have a strong impact onrepellency, but related researches are still lack.In this research, the insect repellent DEET (N, N-Diethyl-3-methyl benzoyl amide,DEET), terpenoid repellent R2(hydroxy citronellal,-1,2-propanediol acetal) and the3main human attractants (ammonia, L-lactic acid and1-octene-3-alcohol) are selected asresearch objects. In the meantime, Aedes albopictus is the selected mosquito. On the basisof the early chemical calculation, we take advantage of olfactometer and electroanten-nography to study the association effect between repellents and main human attractants andestimate the influence of which on mosquitoes’ behavior and antennal electrophysiology.This research aims to enrich the study of Aedes albopictus and provide new ideas and for-mer foundation for the study of repellent mechanism. The results are as follows:1. The experimental results of attractants show that attractive activities and electroan-tennogram (EAG) of3main human attractants (ammonia, L-lactic acid and1-octene-3-alcohol) have the same varying trend. With the increase of concentration of attractants,luring effect and EAG intensity to Aedes albopictus increase accordingly.2. The experimental results of repellents indicate that, with the increase of concentra-tion, the repellent effect and EAG intensity of DEET and R2to Aedes albopictus increasesaccordingly. In the concentration of1000mg/L and100mg/L, the repellent effect of tworepellent compounds (R2and DEET) on Aedes albopictus is basically the same. Conse-quently, we infer the terpenoid repellents R2can be used as repellents on Aedes albopictuscontrol.3. The experimental results of unimolecular association between repellents and mainlyhuman attratcants reveal that it can significantly improve repellent activity and EAG inten-sity to Aedes albopictus after DEET and R2unimolecular association with ammonia and1-octene-3-alcohol respectively. And its enhanced range depends on the increase of con-centration. Compared with the repellent compounds functioning alone, it will impair theinfluence of repellent activity and EAG intensity to Aedes albopictus after attractant L-lactic acid unimolecular association with two repellent compounds.4. The experimental results of polymolecular association between repellents andmainly human attratcants indicate that, after DEET and R2polymolecular association withhuman attractant (ammonia and L-lactic acid) respectively, it can reduce the repellent ac- tivity to Aedes albopictus, while it can improve the unreactive rate and reduce the attrac-tant rate to Aedes albopictus. Polymolecular association not only reduce directly repellentactivity to Aedes albopictus, but also increase the repellent activity by improviong the un-reactive rate and reducing the attractant rate to Aedes albopictus. At the same time, theexperimental data of EAG also indicates that the EAG intensity caused by polymolecularassociation is slightly weaker than the consequence of repellents functioning alone. How-ever, compared with attractants functioning alone, polymolecular association has improvedsignificantly. As a result, repellent activity of polymolecular association to Aedes albopic-tus is similar to the consequence of repellents functioning alone. But the way of poly-molecular association acts on Aedes albopictus is different from repellents functioningalone. And it can be more complex.To sum up, there are unimolecular association and polymolecular association betweenrepellent (DEET and R2) and3major human attractant (ammonia, L-lactic acid and1-octene-3-alcohol). And this association has a significant influence on the repellent activ-ity to mosquitoes.