Thursday, April 17, 2014

Renanthera monachica in Puerto Rico damaged by a native orchid weeveil Stethobaris polita

An intact flower for comparison.

Last week I was looking forward to enjoying the beauty of an inflorescence of Renanthera monachica with all its flowers open.  Distressingly, I found that something had damaged the open flowers and some of the buds.  But it was not obvious which animal was causing the damage.  I visited the flowers several times during the day and then found that the culprit for the damage was a native orchid beetle, Statobaris polita.  I checked all my other orchids and the only one that had beetles was the Renanthera.  I only use pesticides as a weapon of last resort.  What I do with these weevils is that when I find them in flowers, I put a small cup with a combination of detergent and alcohol under the flower and then I shake the flower gently.  The weevils will react by helpfully dropping into the cup and partaking of the detergent and the alcohol.  These weevils are a seasonal pest, months can go by without one showing on the flowers and then they start to appear, but never in large numbers.  At the peak of their infestation I can find five to ten a week in the flowers.  They had not been a problem before the exotic orchid Sphatoglottis plicata established large populations in the forest.  I saw the first Sphatoglottis plant in the forest, a white one, in 2004, now they are common and in some places downright abundant.

1 comment:

jwd said...

Hi Ricardo,
We have something great in common. I am a retired Engineer, now an "Orchid Nut" case.
I am married to a Puerto Rican lady and we live in England.
We did live in Fajardo for nearly ten years.
A couple of days ago I bought a Reynanthera monachiaca, and that's where our thread begins.
I hope to hear from you.
John Dennis