Annual population dynamics of Scirtothips dorsalis Hood (Thysanoptera: Thripidae) on two ornamental hosts, Rosa 'Radrazz' L. and Conocarpus erectus L. in southern Florida

Scirtothrips dorsalis Hood (1919) is an invasive thrips recently established in southern Florida. The phenology of this thrips was observed from July 2007 to September 2008 on two hosts: the Knock Out Rose ®, Rosa ‘RADrazz’; and buttonwood, Conocarpus erectus L. Populations were sampled weekly using yellow sticky traps, and through biweekly collection of host flowers and growth terminals. Environmental data was recorded using the FAWN weather station.

S. dorsalis was the predominant thrips collected on and above both hosts throughout the experiment, with Rosa consistently showing both absolutely and relatively greater abundance of S. dorsalis than C. erectus. Peak flight captures were observed over rose in August, October, November of 2007 and June of 2008. Peak flight captures were observed over buttonwood in May and June of 2008. The highest S. dorsalis densities were observed on rose during October of 2007, and January, March, May, and July of 2008. Damage peaks occurred on rose in October and November of 2007, and February and July of 2008.

No strong linear correlation was observed between any single environmental variable and thrips populations on or above hosts. Multiple linear regression failed to identify strong correlation for groups of environmental variables. Some correlation was observed between on-plant population density, flight captures, and damage.