Damage threshold levels of Frankliniella occidentalis in ornamentals
Experiments were carried out in Switzerland to establish damage threshold levels for Frankliniella occidentalis (EPPO A2 quarantine pest) in different ornamental crops. Blue sticky traps were used at a rate of 1 trap/100 mý in order to monitor the F. occidentalis populations. Three damage threshold levels were evaluated accordingly and were mainly dependent on plant species and temperatures:
Saintpaulia and Streptocarpus had a low damage threshold level of ;10 thrips/trap/week.
Chrysanthemum, Gerbera, Impatiens, Rosa and Sinningia had a medium threshold level of 18-30 thrips/trap/week.
Begonia and Poinsettia had a high damage threshold level of ;40 thrips/trap/week.
Sources
Frey, J.E. ;(1993) ;Damage threshold levels for western flower thrips, Frankliniella occidentalis on ornamentals.
IOBC/WPRS Bulletin, Vol. 16(8) 1993, 78-81.