Effect of Flower Thrips on Onion Seed Plants and a Study of Their Control

The Diversity and Abundance of Small Arthropods in Onion,Allium cepa, Seed Crops, and their Potential Role in Pollination

“…Most other studies using exclusion or inclusion cages do not identify small arthropods as significant pollinators of A. cepa . Carlson ( 1964 ) recorded slightly higher levels of seed set from caged A. cepa umbels containing thrips compared with cages where all arthropods were excluded, but the difference was not significant. Woyke ( 1982 ) found that A. cepa within exclusion cages did not set any seed, however, Kumar et al ( 1985 ) found that umbels within exclusion cages still set about a third of the seed that uncaged A. cepa set.…”

“…Bohart et al ( 1970 ) referred to the presence of tiny flies on flowering A. cepa umbels, however, they did not define their size or provide data on their abundance or diversity. Carlson ( 1964 ) noted that the presence of Thysanoptera on A. cepa umbels may have contributed to pollination, while Howlett et al ( 2009b ) noted the presence of small arthropods from several orders as being present within flowering A. cepa fields in New Zealand.…”

“…A. cepa flowers are known to attract a diverse array of large arthropods ( Free 1993 and references within), and of these Hymenoptera (particularly bees) and Diptera are usually the most abundant flower visitors ( Bohart et al 1970 ; Howlett et al 2009b ) and key pollinators ( Bohart et al 1970 ; Currah 1981 ; Kumar et al 1985 ). Although small flower-visiting arthropods have been noted, including Thysanoptera ( Carlson 1964 ) and Diptera ( Bohart et al 1970 ; Howlett et al 2009b ), the composition of the small arthropod fauna present within flowering A. cepa fields and their role in pollination remain poorly defined.…”

Pollination potential of thrips (Insecta: Thysanoptera) in some Solanaceous plants

“…The pollination potential of thrips though recognised as early as 1914 by Shaw in sugarbeet and by Annand (1926) in such cultivated crops as sugarbeet, alfalfa, plum and daisey, further confirmation of their active involvement in pollination is referable to the contributions of Hagerup (1950) on Calluna and Erica (Hagerup and Hagerup 1953), Billes (1941) on cacao by Frankliniella Odland and Porter (1941) on Capsicum annuum, Carlson (1964) on onion and Ananthakrishnan et al(1981Ananthakrishnan et al( . 1982Ananthakrishnan et al( and 1984 on Asteraceae (= Compositae).…”