|Harlow, C - N. C. STATE UNIVERSITY|
|Sisson, V - N. C. STATE UNIVERSITY|
Submitted to: National Research and Action Plan for Silver Leaf Whitefly
Publication Type: Abstract Only
Publication Acceptance Date: February 14, 1997
Publication Date: N/A
Technical Abstract: Sugar esters are effective biorational insecticides for control of soft-bodied insects such as whiteflies and aphids. Production of sugar esters by 8 Nicotiana species was assessed at Florence & Charleston, SC and Tifton, GA, 1995. All Nicotiana species survived transplantation well, but survival was poor for some species after the second cutting. Cuticular components from 50 plants/plot were removed by isopropanol, and sugar esters were analyzed by GC. N. gossei, N. langsdorffii, N. noctiflora, and N. amplexicaulis produced the most green-weight biomass. Sugar esters levels increased with subsequent harvests. Despite being a poor biomass yielder, N. trigonophylla produced the highest levels of crude cuticular extract at 9.0 g/50-plant plot, compared to N. gossei at 4.7 g/plot. After purification, N. trigonophylla yielded 6.2 g or sugar- esters/plot (2.2 kg/ha) compared to 1.6 g/plot for N. gossei. The sugar ester biorational from N. trigonophylla is active against aphids and whiteflies, and it is comparable to the biorational material from N. gossei. Because the surface component profile of N. trigonophylla is less complex than that of several other Nicotiana species, the sugar ester fraction is comparatively easy to fractionate. Therefore, N. trigonophylla appears to be a superior source of sugar esters for use as a biorational insecticide.