Effects Of Honeydew On The Behavior And Biogenic Amine Content Of Red Imported Fire Ants(Hymenoptera:formicidae)

Mutualism is a common phenomenon among species in nature.,The interaction between the fire ants(Solenopsis invicta Buren)and the mealybug(Phenacoccus solenopsis Tinsley)is a typical example.The relation of ant-mealybug is linked by honeydew,Mealybug provides honeydew for fire ants,in return,fire ants against predation and parasitic natural enemies for it.Honeydew plays a key role in the invasion of red imported fire ants,its regulation on the behavior of red imported fire ants intensifies their inhibition on native ants and other arthropods,the presence of chemicals in honeydew may play an important role in the ants’ caretaking and localizing behavior,but the mechanism by which honeydew regulates the behavior of red imported fire ants is still poorly understood.In this study,by measuring the changes in the movement behavior and aggression behavior of red imported fire ants after feeding on honeydew and the main carbohydrate components,the correlation between these behavioral changes and the amount of biological amines in the brain was analyzed,and the mechanism of the regulation of red imported fire ants by honeydew was further explored.The main findings are as follows:1.Honeydew of mealybug significantly improves the activity and aggressive behavior of red fire ants.The results showed that after feeding mealybug honeydew for 24 h,the time of red imported fire ants crossing the center line was 114.2 times /5min,which was significantly higher than the 35.2 times /5min of the control group,and the attack index was as high as 2.97,which was significantly higher than other treatments.after feeding mealybug honeydew for 72 h,there was no significant difference in exercise activity compared with the control group,and the attack index was 3.09,which was improved compared with the control group.From this we can see that the honeydew excreted by mealybug can make red imported fire ants excited to a certain extent.2.Fructose and matsulose in the honeydew of the mealybug are important components to regulate the behavior of red imported fire ants.Further research results showed that in the case of 20% sugar concentration,fructose promoted the activity of red imported fire ants,and the number of red imported fire ants crossing the center line reached 52.2 times/5min.Songtrisaccharide promoted the activity and aggression of red imported fire ants.Red imported fire ants crossed the center line 53.2 times /5min,and the attack index was3.05,which was significantly higher than other treatments.However,at 5% concentration,there was no significant difference in the effect of various sugars.It can be concluded that the mealy bug honeydew is mainly regulated by the internal fructose and teratose to the behavior of red imported fire ants.3.The content of biogenic amine is closely related to the activity of worker ants.The results showed that reserpine treatment could reduce the biogenic amine content of red imported fire ants.After 120 hours of treatment,the movement activity and the aggression of red fire ant workers in the reserpine fed treatment group was significantly reduced,It can be concluded that the decrease of biogenic amine will inhibit the activity and aggression of worker ants.4.Finally,the worker ants treated with honeydew and reserpine were analyzed by HPLC,the results showed that reserpine treatment could effectively reduce the content of serotonin in individual workers,and the red imported fire ant workers that had eaten the mealybug honeydew,the brain concentrations of tyramine and serotonin were 10.75μg/ml and 0.50μg/ml,respectively,compared with the control group of 5.75μg/ml and 0.14μg/ml,there was an improvement.It can be seen that the individual vitality of red fire ant is related to the content of biogenic amine,while honeydew can effectively improve the biogenic amine content of red fire ant worker ant,thus improving the vitality of red fire ant.To sum up,honeydew of mealybug not only provides nutrients for red fire ants,but also regulates ant behaviors and strengthens the reciprocal relationship between ant and mealybug.