Abstract
Thrips tabaci is a major pest of high-value vegetable crops and understanding its population genetics will advance our knowledge about its ecology and management. Mitochondrial cytochrome oxidase subunit I (COI) gene sequence was used as a molecular marker to analyze T. tabaci populations from onion and cabbage fields in New York. Eight COI haplotypes were identified in 565 T. tabaci individuals collected from these fields. All T. tabaci were thelytokous and genetically similar to those originating from hosts representing seven plant families spanning five continents. The most dominant haplotype was NY-HT1, accounting for 92 and 88% of the total individuals collected from onion fields in mid-summer in 2005 and 2007, respectively, and 100 and 96% of the total in early fall in 2005 and 2007, respectively. In contrast, T. tabaci collected from cabbage fields showed a dynamic change in population structure from mid-summer to early fall. In mid-summer, haplotype NY-HT2 was highly abundant, accounting for 58 and 52% of the total in 2005 and 2007, respectively, but in early fall it decreased drastically to 15 and 7% of the total in 2005 and 2007, respectively. Haplotype NY-HT1 accounted for 12 and 46% of the total in cabbage fields in mid-summer of 2005 and 2007, respectively, but became the dominant haplotype in early fall accounting for 81 and 66% of the total in 2005 and 2007, respectively. Despite the relative proximity of onion and cabbage fields in the western New York landscape, T. tabaci populations differed seasonally within each cropping system. Differences may have been attributed to better establishment of certain genotypes on specific hosts or differing colonization patterns within these cropping systems. Future studies investigating temporal changes in T. tabaci populations on their major hosts in these ecosystems are needed to better understand host-plant utilization and implications for population management.
Highlights
Thrips tabaci Lindeman is a major insect pest of multiple crops worldwide including two high-value vegetable crops, onion, Allium cepa L., and cabbage, Brassica oleracea capitata (L.) [1]
Understanding the genetic structure of T. tabaci populations in cropping systems will advance our knowledge about its population ecology, which can be important for developing effective management strategies [9]
Our results revealed a commonality in the most abundant T. tabaci haplotypes from onion and cabbage fields and these haplotypes were genetically similar to those originating from an array of hosts and locations around the world
Summary
Thrips tabaci Lindeman is a major insect pest of multiple crops worldwide including two high-value vegetable crops, onion, Allium cepa L., and cabbage, Brassica oleracea capitata (L.) [1]. Genetic differences between T. tabaci populations from tobacco and populations from onion and leek have been documented [7], [8]. In New York (USA), T. tabaci infestations in onion and cabbage fields are routinely managed with applications of insecticides. Insecticide resistance in T. tabaci populations in onion fields has been widespread [10], [11]. Seasonal susceptibility shifts in T. tabaci populations in onion fields to insecticides have been documented [10], [11]. Some populations were susceptible to insecticides in mid-summer, but tested resistant to them in early fall, and vice versa. These observations suggest that there may be host-associated differences among T. tabaci populations and that they may change during the season
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
