BIOLOGICALLY-BASED TECHNOLOGIES FOR MANAGEMENT OF CROP INSECT PESTS IN LOCAL AND AREAWIDE PROGRAMS
Location: Insect Behavior and Biocontrol Research Unit
Title: Predator-Prey Relationships on Apiaceae at an Organic Farm
Submitted to: Journal of Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 1, 2012
Publication Date: June 1, 2012
Citation: Shirk, P.D., Shapiro, J.P., Reitz, S.R., Gruters Thomas, J.M., Koenig, R.L., Hay-Roe, M.M., Buss, L.J. 2012. Predator-Prey Relationships on Apiaceae at an Organic Farm. Journal of Environmental Entomology. 41(3):487-496.
Interpretive Summary: “Banker plants” can be used to aid in the establishment and conservation of natural or augmented populations of beneficial insects for biocontrol. Scientists at the USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, identified two related species of flowers, Queen Anne’s lace and false Queen Anne’s lace, that are grown on an organic farm near Gainesville, Florida that function as a reservoir for two species of minute pirate bugs that are beneficial predatory insects. Adults of both the insidious flower bug (Orius insidiosus) and the relatively unknown species Orius pumilio were the primary predators of the Florida flower thrips infesting these flowers during a growing season. The thrips population declined in a density dependent manner as the predator populations increased. Most critically for vegetable and ornamental growers, the study offers the promise of employing these flowers as banker plants to attract pest insects and harbor natural predators to augment biological control on Florida organic farms, in greenhouses, and potentially on field crops.
Orius insidiosus and O. pumilio were confirmed to be sympatric in north central Florida as the major predators of the Florida flower thrips, Frankliniella bispinosa, on flowers of Queen Anne’s lace, Daucus carota and false Queen Anne’s lace, Ammi majus. F. bispinosa was the predominant thrips observed on both flowers but colonized D. carota to a greater extent and earlier in the season than A. majus. Despite differences in the abundance of F. bispinosa on the two plants, neither Orius species showed host plant affinities. Population profiles for the thrips and Orius spp. followed a density dependent response of prey to predator with a large initial prey population followed by a rapid decline as the predator populations increased. The temporal increases in O. spp. populations during the flowering season suggest that they were based on reproductive activity. As observed in a previous study, O. insidiosus had a larger population than O. pumilio and also had a predominantly male population on the flowers. By examining carcasses of the prey, there appeared to be no sexual preference of the thrips as prey by the Orius spp. as the prey pattern followed the demographics of the thrips sex ratio. Few immatures of either thrips or Orius spp. were observed on D. carota or A. majus which suggests that oviposition and nymphal development occurred elsewhere. Based on these findings, D. carota and A. majus could serve as a banker plant system for Orius spp.