Question
Hi,

I just found out today that the oncidum orchid I bought less than two weeks ago had some small yellow bugs on it.  Those bugs also laid eggs on my oncidium flowers.  Is it because I put some egg shell on it?  I heard th
at egg shell will help orchid grow, is it true?  

Eileen

Answer
Hi Eileen,

I'm afraid I don't know what those small yellow bugs on your oncidium orchid are.  If it were white fuzzy insects then it would be mealy bugs.  If it were very tiny red insects, probably spider mites.  Small dark brown spots that slowly move, probably brown scale.  Small whitish spots, probably boisduval scale.  Really tiny spiders (need a magnifying glass to see), probably false spider mites which make tiny holes on the underside of leaves.  

Oops!  It just dawned on me what those yellow bugs might be!!  Thrips!  Thrips are tiny chewing insects that crawl around pretty fast for their size.  Thrips feed on leaves leaving a tell tale silvery area on the leaves they are feeding upon.  If you have some malathion or diazanon insect spray, take your oncidium outdoors in the morning and liberally spray it, being sure to get the underside of the leaves.  Leave it outdoors until it is dry and the chemical smell is gone before bringing it back indoors.  

Egg shells is an old gardeners method of adding calcium to the soil.  Crush the egg shells then sprinkle a little on top of the potting mix then water to get it to trickle down into the pot.  Each time you water, your plant will get a tiny amount of calcium which may help promote root growth.  As for if it will help the orchid to grow, the simple answer is yes.  Remember, a healthy root system leads to a healthy plant.  

Hope this helps.  Good luck and good growing.

Jim