Ecological and physiological factors influencing transmission of Tomato spotted wilt virus (TSWV) by Frankliniella fusca and F. occidentalis
Stumpf CF, Kennedy GG
Department of Entomology, Box 7630, North Carolina State University, Raleigh, NC
Correspondence: cfstumpf@ncsu.edu
Tomato spotted wilt virus (TSWV) replicates in its thrips vectors. Findings will be presented that demonstrate both direct effects and host plant-mediated effects of TSWV infection on thrips performance as measured by development time, survival, and adult size for Frankliniella fusca, but only host plant-mediated effects for Frankliniella occidentalis. The magnitude of these effects and their consequences on transmission rates are influenced to varying degrees by the main effects and interaction effects of temperature, host plant, and TSWV isolate. The potential implications of these findings for the epidemiology of TSWV will be discussed.
Effect of organic and conventional production methods on thrips (Thysanoptera: Thripidae) species occurrence in field grown cut flowers
Sutliff-Shipley S, Casey C
Department of Entomology, Box 7613, North Carolina State University, Raleigh, NC 27695 USA.
Correspondence: ssutlif@ncsu.edu
Field cut flower production in North Carolina is a growing industry as tobacco farmers move to flower production. Thrips are the most serious insect pest problem for these growers as they feed directly on flowers, which causes scarring and distortion, thereby reducing the crop¨s value. Several species of thrips also vector fatal tospoviruses such as impatiens necrotic spot virus (INSV) and tomato spotted wilt virus (TSWV). Little is known about thrips species occurrence in cut flower production. A preliminary survey of cut flowers in organic production indicates that the most predominant species of thrips is eastern flower thrips (Franklinilla tritici), which is not a tospovirus vector. However, it is unknown which species are predominant in conventional production and if farm location, soil type, and history also factor into thrips species distribution. The objective of this investigation is to identify the thrips species that occur in both organic and conventional field flower production in North Carolina. Seven farms (3 organic and 4 conventional) were sampled during the 2005 cut flower growing season. Thrips were sampled indirectly via yellow sticky cards as well as directly by biweekly sampling of 3 crop plant and 3 weed species . Knowledge of species distribution provided by this investigation will be a starting point for improved thrips management programs for both conventional and organic growers.
