scholarly journals Thelytokous Reproduction of Onion Thrips, Thrips tabaci Lindeman 1889, Infesting Welsh Onion and Genetic Variation among Their Subpopulations

Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 78
Author(s):  
Falguni Khan ◽  
Miltan Chandra Roy ◽  
Yonggyun Kim

Parthenogenesis is not uncommon in thrips. This asexual reproduction produces males (arrhenotokous) or female (thelytokous). Only females are found in the onion thrips (Thrips tabaci Lindeman 1889) infesting Welsh onion (Allium fistulosum) in several areas of Korea. To determine the reproduction mode of T. tabaci, thrips infesting Welsh onion were collected from different localities in Korea. Cytochrome oxidase I (COI) sequences were then assessed. Results showed that all test local populations had signature motif specific to a thelytokous type. These COI sequences were clustered with other thelytokous populations separated from arrhenotokous T. tabaci populations. In a laboratory test, individual rearing produced female progeny without any males. These results support that Korean onion thrips infesting Welsh onion have the thelytokous type of parthenogenesis. Local thrips populations exhibited significant variations in susceptibility to chemical and biological insecticides. Random amplified polymorphic DNA (RAPD) analysis indicated genetic variations of local populations. However, the genetic distance estimated from RAPD was independent of the actual distance among different local populations. These results suggest that genetic variations of T. tabaci are arisen from population subdivision due to asexual thelytokous reproductive mode.

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Marta Olczyk ◽  
Maria Pobożniak

AbstractWe determined the abundance, species composition, sex ratio and seasonal dynamics of thrips on one cultivar of Welsh onion (Allium fistulosum) and eight cultivars of onion (Allium cepa) in South Poland within three vegetation seasons (2014–2016). Nine species of Thysanoptera were identified on A. cepa and A. fistulosum. Irrespective of the onion cultivar, Thrips tabaci was the dominant species (64.4% of all collected thrips specimens), while Frankliniella intonsa also occurred in high numbers (28.3%). Conversely, Welsh onion was most often inhabited by F. intonsa (62.7%), although T. tabaci was also numerous (28.3%). The predatory Aeolothrips intermedius accounted for 4.5% on A. cepa and 2.9% on A. fistulosum. In the most numerous species, T. tabaci, F. intonsa and A. intermedius populations were formed mainly by females. The cultivar most colonised by thrips was Kroll of A. fistulosum. The tested cultivars of A. cepa demonstrated varying degrees of attractiveness to thrips in the subsequent years. The relationship between populations of T. tabaci, F. intonsa and A. intermedius changed in the subsequent months of the growing season. In June, mainly T. tabaci and F. intonsa occurred on onion plants, while from July, the percentage shares of F. intonsa and the predatory A. intermedius in the thrips population on many onion cultivars increased. The level of attractiveness of A. cepa related to onion thrips, which is reported as a main pest of onion, varies depending on the year and cultivar.


2020 ◽  
Vol 28 (1) ◽  
pp. 21-28
Author(s):  
Wondimagegn Atilaw Woldemelak

AbstractThe present study aimed to investigate whether adult males could fertilize immature female pupae in the leek (L1) and tobacco-associated (T) Thrips tabaci lineages and to investigate the potential effects of mother to son inbreeding on the appearance of deuterotokous females in the T lineage. To confirm the pupal insemination, a single female pupa was exposed to a single adult male for 24 hours. The removal of a male from the tube that contained the female pupa was made before the female pupa emerged to adulthood. Emerged female adults were isolated and reared individually and the sex of their progeny was determined in the larval stages. To examine a mother and son inbreeding, a single female adult was exposed to her son for 48 hours, and for two consecutive generations, the mode of reproduction was determined by identifying the sex of the progeny. This result showed that pupal insemination was not successful; thus, all the tested females produced only male progeny. Virgin inbred females produced both male and female progeny that refers to deuterotokous reproduction mode. Three virgin females produced a total of 20 females and 75 males in two consecutive generations. A study concluded that deuterotokous mode of reproduction is not a persistent mode of reproduction in the T lineage but is a result of irregularity in the mode of reproduction, and it might be changed because of brother and sister inbreeding and need further studies.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 506d-506
Author(s):  
Robert R. Tripepi ◽  
Holly J. Schwager ◽  
Mary W. George ◽  
Joseph P. McCaffrey

Two insecticides, acephate or azadirachtin, were added to tissue culture media to determine their effectiveness in controlling onion thrips (Thrips tabaci Lindeman.) and to determine if these insecticides could damage the plant shoot cultures. To test for insecticide phytotoxicity, microshoots from European birch (Betula pendula), American elm (Ulmus americana), `Pink Arola' chrysanthemum (Dendranthema grandiflora), `America' rhododendron (Rhododendron catawbiense), `Golden Emblem' rose (Rosa hybrida), and `Gala' apple (Malus domestica) were placed in 130-ml baby food jars containing 25 ml of medium supplemented with 6.5, 13, or 26 mg/l Orthene® (contained acephate) or 0.55, 1.1, or 2.2 ml/l Azatin® (contained azadirachtin). Control jars lacked insecticide. To test for thrips control, 13 mg/l Orthene® or 0.55 ml/l Azatin® was added to Murashige and Skoog medium, and 10 thrips were placed on `Gala' apple microshoots in each jar. Jars were sealed with plastic wrap. In both studies, microshoot dry weight and heights were determined. In the second study, the total number of thrips per jar was also determined 3 weeks after inoculation. Microshoots on Orthene®-treated media lacked phytotoxicity symptoms, regardless of the concentration used. In contrast, Azatin® hindered plant growth, decreasing shoot height or dry weight by up to 85% depending on the species. Both insecticides prevented thrips populations from increasing, since less than 10 thrips were found in jars with insecticide-treated medium. Control jars, however, contained an average of almost 70 thrips per jar. This study demonstrated that both Orthene® and Azatin® were effective for eradicating thrips from plant tissue cultures, but Orthene® should probably be used because Azatin® was phytotoxic to all species tested.


2021 ◽  
Vol 83 (1) ◽  
pp. 21-24
Author(s):  
V Karuppaiah ◽  
S J Gawande ◽  
V Mahajan ◽  
M Singh

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