Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/6/2011
Publication Date: 3/1/2012
Citation: Kumar, V., Seal, D.R., Kakkar, G. McKenzie, C.L., Osborne, Lance L.S. 2012. New tropical fruit hosts of Scirtothrips dorsalis (Thysanoptera: Thripidae) and its relative abundance on them in South Florida. Florida Entomologist. 95:205-207. Available: http://dx.doi.org/10.1653/024.095.0134. Interpretive Summary: The chilli thrips, Scirtothrips dorsalis Hood is a serious pest of various vegetable crops, cotton, citrus and other fruit and ornamental crops in its principal range in southern and eastern Asia, Africa, and Oceania where it is known to kill newly emerged seedlings, severely distort leaves and scar the surface of fruits of its favored host. It is a severe pest with an extensive host range and an expanding worldwide distribution including the United States. Since chilli thrips’ establishment in Florida in 2005, it has been reported on 38 different ornamental crops with a few reports on vegetable peppers. This is the first report in Florida where S. dorsalis has been found damaging fruit hosts on a commercial scale. Seven out of 12 crops monitored showed continuous infestations despite chemical and biological control measures resulting in economic damage to these crops. Eight out of 12 crops infested at the nursery had never been reported as host plants of this pest in the literature with canistal, mango, sapodilla and miracle fruit being the most impacted by chilli thrips infestations. As this pest continues to broaden its geographical distribution it is important to monitor potential plant hosts for thrips infestation as it appears to be expanding its plant host range as well.
Technical Abstract: Chilli thrips, Scritothrips dorsalis Hood, recently established in the southeast region of the United States, poses an economic threat to a wide-range of ornamental and vegetable plants. During scouting and sampling various hosts at different commercial nursery locations in Florida (Miami-Dade County), some of the fruit crops were found to be affected by S. dorsalis. Eight out of 12 crops infested at the nursery had never been reported as host plants of this pest in the literature. An open free choice host susceptibility test was conducted among the most affected hosts observed at the nursery. Canistal, mango, sapodilla and miracle fruit were found to be most affected among the six fruit hosts that were further evaluated. Results from this study are important in reporting new hosts of S. dorsalis in the United States and show their adaptability in a new geographical region where the pest does not have access to their favored hosts. It is worth mentioning that these new crops, which are less susceptible to attack in the presence of preferred hosts, can be prone to high infestations of S. dorsalis in their absence. In addition, it is important from an extension research point of view that crops which have never been reported as hosts of this pest must not be neglected when scouting and sampling for S. dorsalis infestations, as its host range is continuing to spread in this region.