Study On Spatial Distribution Pattern And Monitoring Techniques Of Red Imported Fire Ant (Solenopsis Invicta Buren)

The red imported fire ant (RIFA) , Solenopsis invicta Buren (Hymenoptera: Formicidae) is a well-known invasive ant, originating in Panama river of South America.It brings badly damage to the ecological environment of invasion according to its great ecological advantages,even the loss of biodiversity.In Jinjiang city of Fujian Province, it was firstly found in July 2007. The research of RIFA was carried out during Augest 2007 and December 2008.To provide a basis for biological and ecological mechanism research on ants, its spatial distriubution and its population dynamics were studied, and relevant monitoring technology was put forward. The results were as follows:(1) According to the systemmatic investigation of active mounds spatial distribution in various habitats, the results show that the spatial distribution pattern of most active mounds obey aggregation distribution. The active mounds density had a relatively remarkable impact on active mounds spatial distribution: the active mounds randomly distributed at low density, while they shown a pattern of aggregation distribution at relatively high density. According to theoretical most optimum sampling quadrats number studied based on spatial distribution of ant population, 250 to 450 quadrats were required at an active mounds dense of 1 to 2 mounds per 100 square meters; while 60 to 110 quadrats required for 5 to 10 mounds per 100 square meters and 20 to 60 quadrats for 10 plus mounds.(2) The following experiment explored the best baiting time and the critical number of quadrats, with 80 minutes after baits set being found the best baiting time, and the critical numbers of quadrats for various habitats being determined.(3) According to the study on ant population dynamics, the ant population in various habitats was efficiently controlled by chemical treatments, and temperature was another key factor to the population control. Moreover, complicated habitats provided shields for ants against chemical control etc., but ants'outbreak was limited in habitats with high vegetation density, in where RIFA is not suitable for ants'difusing or colonizing.