Effect of the Arthropod Community on Survivorship of Immature Haematobia irritans (Diptera: Muscidae) in North Central Florida

Field mortality of horn flies caused by the arthropod community was tested by seeding colony-reared horn fly (Haematobia irritans L.) eggs underneath artificial cattle pats placed in the field and collecting the emerging flies using cone traps. Mean numbers of horn flies that emerged from pats exposed to the whole arthropod community during the developmental period of the immature stages were significantly lower than those from pats isolated from all members of the community except Solenopsis invicta Buren. The community-caused mortalities of horn flies were 75.9% and 66.7% in July and August 1992, respectively, with an overall average of 71.3%. Predation by S. invicta raised mortality to at least 93.9%. These results suggest that the other arthropods in cattle dung played an important role in reducing horn fly populations in north-central Florida.