Seasonal Changes in Thrips tabaci Population Structure in Two Cultivated Hosts

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.

Onion thrips Thrips tabaci [Thysanoptera: Thripidae] reduces yields and THC in indoor grown cannabis

“…For its part, the onion thrips have a diversified range of hosts, including onion, leek, broccoli, cabbage, tobacco, cotton, and ornamentals (Diaz-Montano, Fuchs, Nault, Fail, & Shelton, 2011;Nault, Kain, & Wang, 2014;Stuart et al, 2011) and has long been recognized as a greenhouse pest (Morison, 1957). In onions, it can notably reduce yields, sometime by more than 50% (Diaz-Montano et al, 2011;Fournier, Boivin, & Stewart, 1995), and as little as 10 thrips per plant is sufficient to decrease yields by 7% in greenhouses (Kendall & Capinera, 1987).…”

Molecular characterisation of Thrips tabaci Lindeman, 1889 (Thysanoptera: Thripidae) populations in Hungary based on the ITS2 sequences

“…Secale cereale and vector competency of various TSWV isolates in North Carolina, where T. tabaci does not play a role in TSWV transmission in tobacco (Jenser et al 2011). Phylogenetic studies concerning different reproductive modes and geographically distinct thrips populations revealed similar tree composition to the host plant preference: thelytokous and arrhenoto kous haplotypes divided into two or three main clades (Jacobson et al 2013, Toda & Murai 2007, Nault et al 2014. In our experiments we extended the number of host plant species in order to support our hypothesis that the split between the two main clades or biotypes could have happened by an adapting mechanism to tobacco across an intermediate breeding host that might be a relative taxon of Nicotiana tabacum.…”

“…As the first reported vector of Tomato spotted wilt virus (TSWV) causes serious epidemics and heavy crop losses worldwide (Pittman 1927). Until the report of Zawirska (1976) it was known as an unambiguous unitary species.…”

“…To study the very complex interaction/correlation between host plant preference, vector competency, reproduction forms and population genetics, DNA barcoding proves to be a suitable tool. For this purpose, most of the publications deal with mitochondrial COI (and COII) sequence analysis (Brunner et al2002, 2004, Kobayashi & Hasegawa 2012, Nault et al 2014, Toda & Murai 2007, Jacobson et al 2013. Internal transcribed spacer 2 region of the rDNA is mostly used at interspecific level (Glover et al 2010, Buckman et al 2012) but hence Thrips tabaci seems a more complex taxon that comprises of two or more subspecies or even cryptic species (Brunner et al 2004), we chose this marker to differentiate the populations according to host plant and to compare our results to the analysis of the COI sequences completed by others.…”

Genetic structure and diversity of western flower thrips, Frankliniella occidentalis in a French bean agroecosystem of Kenya

“…For example, it might explain the high variability in thrips population densities on crops, which can depend on the composition of surrounding plant species (e.g. Nault et al, 2014) and which may affect crop and intercrop selection at farm level. As a result, specific trap crops, intercropping, and other management approaches (entomopathogenic fungi and nematodes, beneficial insects, biological strategies involving pheromones, etc.)…”