Predator-prey relationships on Apiaceae at an organic farm.
Orius insidiosus (Say) and O. pumilio (Champion) were confirmed to be sympatric in north central Florida as the major predators of the Florida flower thrips, Frankliniella bispinosa (Morgan), on flowers of Queen Anne's lace, Daucus carota L. and false Queen Anne's lace, Ammi majus L.  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 Orius 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.
Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, US Department of Agriculture, Gainesville, FL 32608, USA. paul.shirk@ars.usda.gov
Paul D
PD
Shirk
Jeffrey P
JP
Shapiro
Stuart R
SR
Reitz
Jean M G
JM
Thomas
Rosalie L
RL
Koenig
Mirian M
MM
Hay-Roe
Lyle J
LJ
Buss
D031165:Ammi; D000818:Animals; D018552:Daucus carota; D005260:Female; D005431:Florida; D020387:Food Chain; D020062:Heteroptera / Q000254:growth & development / Q000502:physiology*; D008297:Male; D058871:Organic Agriculture; D010572:Pest Control, Biological; D011157:Population Dynamics; D012621:Seasons; D013045:Species Specificity; D061149:Thysanoptera / Q000254:growth & development / Q000502:physiology*