Behavioral Adaption And Mechanism Of Native Ants On The Invasion Of Solenopsis Invicta Buren

Behavioral adaption is one an important strategies of native species on biological invasion. Native ant adapt for pressure of resource competition of exotic species by food spectrum and niche differentiating. Red imported fire ant(RIFA) is a hazardous exotic species which had been found to invade in several provinces in southern China.RIFA have a great impact on survival and development of native ant by plundering most of resources in invasive area of RIFA. Behavioral adaption of native ant after RIFA invating was studied, which indicated internal mechanism of the behavioral adaption.(1) The impact of invasion of RIFA on the diversity of ant community in wasteland was studied.The result showed that the impact of the invasion on the diversity of ant community was great in wasteland in which the population and species number of native ant decreased greatly. The number of species of native ant decrease by 28.57% and the number of native ant decrease by 27.81%. The diversity index index of ant community in wasteland decreased with significant difference and the predominance index of ant community in wasteland increased with significant difference, while the evenness of index decrease without significant difference. After the invasion of RIFA, RIFA became a dominant ant species with the biggest population.(2) Behavior adaption of native ants after invasion of RIFAThe result showed that the aggressive index of one-on-one competition between RIFA and T. melanocephalum in un-infested wasteland was higher than that in infested wasteland,which had no significant difference. So did the aggressive index of one-on-one competition between RIFA and Pheidole. fervida Smith. The number of one-on-one competition between RIFA and T. m in un-infested wasteland was bigger than that in infested wasteland,which had significant difference. Moreover, the competition of level? and level ? was4.3 more than that in un-infested wasteland, 82.69% of the increase. The number of one-on-one competition between RIFA and P. fervida in un-infested wasteland was bigger than that in infested wasteland without significant difference, but the competition of level? and level ? was 5.77 more than that in un-infested wasteland, 74.52% of the increase.On the group level, the four mortalities of T. melanocephalum in infested wasteland were lower than that in un-infested wasteland. The mortality of 0.5h and 1h had significant difference, while the mortality of 2h and 3h had no significant difference. The four mortalities of P. fervida in infested wasteland were lower than that in un-infested wasteland but all had no significant difference.The result indicated that the aggressive index of one-on-one competition between RIFA and two native ants after adaptive treatment was lower than that without adaptive treatment.There were two aggressive indices of one-on-one competition between RIFA and T.melanocephalum after adaptive treatment for 0.5h and1 h higher than that without adaptive treatment, which had significant difference. There were three aggressive indices of one-on-one competition between RIFA and P. fervida after adaptive treatment for 1h, 2h and 4h higher than that without adaptive treatment, which had significant difference.The result showed that the invasion of RIFA had a great impact on the foraging behavior of native ants. The number of foraging native ants increased significantly by the increase of foraging time in un-infested wasteland, while the number of foraging native ants increased slowly by the increase of foraging time in infested wasteland. Therefore, the number of native ants foraging for 40 min and50min had significant difference with that in un-infested wasteland.The food selecting experiments indicated that the food of most native ants in infested wasteland foraging was ham sausage, the second most was locust, the third was honey and the last was the bait with ham sausage, locust and honey, while the food of most RIFA foraging was the bait with ham sausage, locust and honey ham sausage, the second most was locust, the third was ham sausage and the last was honey. The food of most native ants in un-infested wasteland foraging was the bait with ham sausage, locust and honey, the second most was ham sausage, the third was honey and the last was locust. It indicated thatthe invasion of RIFA had a great impact on the food selecting of native ants.(3) Effect of stable isotope of native ants after invasion of RIFAThe results of stable isotope showed that the ?15Nair(‰) of both P. fervida(4.64) and T.melanocephalum(3.71) in infested wasteland was more than that(P. fervida: 4.17; T.melanocephalum: 2.57) in un-infested wasteland. Moreover, ?15Nair(‰) of T.melanocephalum in infested wasteland had significant difference with that in un-infested wasteland. It indicated that the invasion of RIFA had a great impact on the foraging behavior of native ants.(4) Effect of diets change on intestinal bacteria structure16 s DNA sequencing report showed that the number of OUT of P. fervida in infested wasteland was 4217, much more than that in un-infested wasteland of 1938. The number of OUT of T. melanocephalum in infested wasteland was 1938, much more than that in un-infested wasteland of 878.So did the chaol index, ACE index, Shannon index and so on,which indicated that diversity and uniformity of intestinal bacteria of two native ants is higher than that in un-infested wasteland. There were two genera Latobacillus and Lactococcus, of T. melanocephalum in infested wasteland significantly less than that in un-infested wasteland, while there was a species, L. garvieae, of T. melanocephalum in infested wasteland significantly more than that in un-infested wasteland. There was a genus,Arthrobacter, of P. fervida in infested wasteland significantly less than that in un-infested wasteland, while there was a species, A. rhizosphaerae, of P. fervida in infested wasteland significantly more than that in un-infested wasteland.