Population Dynamics ofScirtothrips dorsalis(Thysanoptera: Thripidae) and Other Thrips Species on Two Ornamental Host Plant Species in Southern Florida

Abstract

Since its 2005 introduction into the United States, chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), has become a problematic pest of agronomic, vegetable, fruit, and ornamental plants. Knowledge of its population dynamics may help managers better monitor and control S. dorsalis. Population estimates were recorded for S. dorsalis and other thrips species on Knock-Out rose (Rosa 'Radrazz') and green buttonwood (Conocarpus erectus L.) from July 2007 to September 2008 in two field plots (one per plant species) in Homestead, FL. Yellow sticky card traps and samples of terminals, flowers, buds, and leaves were collected. S. dorsalis accounted for 95% of all thrips individuals collected from plants and 84% from traps with the remainder including at least 18 other thrips species. More thrips were caught on or flying near rose plants (47,438) than on or near buttonwoods (5,898), and on-plant densities of S. dorsalis appeared higher for rose than for buttonwood. Compared with rose leaves, rose buds, terminals, and flowers each had higher numbers of S. dorsalis, and buds and terminals had higher densities. On each host plant species, S. dorsalis density fluctuated over time with peaks in the late spring, summer, and fall, but populations were consistently low in the late winter and early spring. On roses, increased plant damage ratings correlated with reduced numbers of flowers and buds, reduced mean flower areas, and increased on-plant number and density of S. dorsalis. There were positive correlations over time between S. dorsalis density and plant damage rating for rose flowers (R = 0.78; P = 0.0003) and for buttonwood terminals (R = 0.90; P = 0.0001). Yellow sticky card traps were effective for monitoring S. dorsalis and may be especially useful and economically justified for the most susceptible hosts, but they also work well for less susceptible hosts. A good S. dorsalis scouting program should hence consider trap catches and symptoms such as leaf distortion, small flower area (size), and thrips population concentrations near buds and terminals.

Direction and Timing of Dispersal ofScirtothrips dorsalis(Thysanoptera: Thripidae) on Select Ornamental Host Plant Species in South Florida

“…This finding suggested initial, random colonization events followed by gradual, more local population growth and expansion to adjacent plants (Seal et al 2006). Mannion et al (2014) compared buttonwood with rose (but not schefflera) and found more S. dorsalis nymphs on rose than on buttonwood plants, but the percentage of the population that was adult appeared larger on buttonwood. Similarly, in the present study, S. dorsalis densities and damage ratings were lower on buttonwood than on schef-flera suggesting the latter may be a better host plant species for survival and reproduction of S. dorsalis.…”

“…According to Mannion et al (2014), a greater diversity and abundance of thrips (including S. dorsalis) was found on or near rose than on or near buttonwood plants. Higher numbers and densities of S. dorsalis were found on rose than on buttonwood throughout the year suggesting rose is a more attractive (or less repelling) host plant species (Mannion et al 2014). At least 19 thrips species including S. dorsalis were found on plants and in traps on or near Knock-Out® rose or green buttonwood plants (Mannion et al 2014).…”

Presence and Distribution of Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) in Colombia

“…In this study, this species was found in an average temperature of 24.4°C in all ecological regions, which means an advantageous condition for its establishment. Additionally, S. dorsalis density has been positively correlated with temperature but negatively correlated with relative humidity and precipitation ( Mannion et al 2014 ). Because the Andean and Caribbean regions are characterized by a bimodal precipitation regimen with changing seasonal average temperatures, but Orinoquia regions have a monomodal rain regime between April and November with more constant average temperature throughout the year ( Pacheco and León-Aristizabal 2001 ), we expect that geographical dispersion and establishment of S. dorsalis will be differential for these three regions.…”

Population Dynamic of Scirtothrips dorsalis Hood (Thysanopetera: Thripidae) on Mango and Associated Weeds Under Low and Intensive Agricultural Practices

“…indica and M. pudica and could not be proven by this study. Nevertheless, weeds surrounding main host could serve as alternate host and serve as a potential reservoir and pathway for thrips moving to preferred hosts (Mannion, Derksen, Seal, Osborne, & Martin, 2014;Song, Kim, Yang, Hong, & Lee, 2013). Aliakbarpour & Md Rawi (2011) indicated that weeds surrounding the canopy of mango were utilized by thrips S. dorsalis as alternate host in pesticide high input and low input orchard.…”