Friday, July 13, 2012

Cuban Laural Thrips – Attack on Ficus!

Cuban Laural Thrips are fairly easy to identify; the damage is quite distinguishable.  They attack only a few species of Ficus, notably the retusa, while most others are immune.  But when thrips become abundant, they will feed on other hosts.

Using their rasping, sucking mouthparts, they feed on the tender, light green leaves causing a sunken purplish red spotting.  As the thrips feed, the individual leaves roll together with the thrips inside.  Eventually, the feeding causes a yellowing of the leaf along with some dark spotting. In the wind and rain these leaves will ultimately drop off.
With small trees, regular pruning of infested branches is often effective. Shearing off a few inches like trimming a hedge, however, should be avoided. This will stimulate new growth which is then susceptible to attack. 

Folded leaves can be unsightly but rarely become serious.  In most cases the thrips can be ignored.  If treatment is needed, common contact insecticides are of little use since the thrips are rolled up inside the leaf.  Using a systemic insecticide like acephate (Orthene) would be more effective.