Mealybug question - Orchid Board

Jerry · #1 06-13-2008, 06:26 PM

I know there is a forum for insects and pests but I cant find a good answer there or anywhere, so forgive me for asking you advanced growers.
I have just this last month found mealybugs on 4 of my orchids and have just found a few crawlers on 3 other orchids. I tried alcohol and cotton swabs but that is so time consuming and they came back fast, so I tried a mixture of alcohol, corn oil, lemon juice, Murphys oil, and water that I found the recipe for online.
The mixture sure kills the bugs but leaves a shiny film on the leaves which hardens and I didn't like the look of it so I washed it off. These bugs are also inside the growing medium in the pots and I am using a semi hydroponic system.
I have scoured this board and the internet for the past week but cant find a systemic insecticide for orchids, I see Beyer has one for roses and ornamentals but am hesitant to try it out on the orchids, considering the fact I am growing them semi hydroponics, can anyone help?

Jerry

Dorothy · #2 06-13-2008, 06:34 PM

As you wait for others to respond, allow me to direct you to these links -
Mealybugs on Orchids
Diagnosing culture problems - Pests
If you are in a real hurry to find out .. here is the archive search for mealybug - http://www.orchidboard.com/community...earchid=194952

shahrezsyed · #3 06-14-2008, 07:46 AM

just spray ALL your chids with 3:7 water and rubbing alcohol or use 3 table spoons tobasco or cayenne pepper with a teaspoon of corn oil in one gallon of water.
glad to be of help.
shahrez

Ray · #4 06-14-2008, 08:12 AM

Spraying will be of little value, as Jerry stated that they were also in the root system - and root mealies are some of the toughest critters to eradicate.

Get yourself a good commercial insecticide - I recommend Orthene or Merit - and in addition to thoroughly wetting the entire surface of all of your plants (not just the ones apparently affected), fill the pots with the solution as well. Repeat several times per the label directions.

Charles · #5 06-14-2008, 10:22 PM

Throw out the potting material and try to get some Malathion. It works, just be careful not to leave it on the plant too long. Rinse it after about an hour or so. And dip the plant to get the roots too. Shake it around in the bucket. And again, do not try to save the potting material.
Malathion is rough stuff, but it works. And if you do not solve this, you will lose your entire collection anyway. I also sprayed the surrounding areas and plants when I find an infestation in the collection. Now, find some malathion and win back the peace.

cb977 · #6 06-14-2008, 11:00 PM

Malathion is nasty stuff, I've heard that it's going to be banned in the near future.

Here's some info on it:
ATSDR - Public Health Statement: Malathion

If you decide to use it, please use caution and follow the directions carefully.

Jerry · #7 06-15-2008, 12:51 PM

Ray, thanks for the reply, as I am using your semi Hydroponics system (which is excellent by the way) do I flood the pot as normal and let the insecticide sit there in the reservoir and flush at the next watering with more of the insecticide mix or flush with normal fertilizer water in between?

Jerry

Jerry · #8 06-15-2008, 01:51 PM

Quote:

Originally Posted by Ray

Spraying will be of little value, as Jerry stated that they were also in the root system - and root mealies are some of the toughest critters to eradicate.

Get yourself a good commercial insecticide - I recommend Orthene or Merit - and in addition to thoroughly wetting the entire surface of all of your plants (not just the ones apparently affected), fill the pots with the solution as well. Repeat several times per the label directions.

Folow up question, Ray wont the insecticide stay in the "Prime Agra" even though I flush?

jerry

Andrew · #9 06-15-2008, 09:08 PM

I tend to use malathion and dimethoate for persistent mealybug infestations. They're very effective but cb977 is correct in that organophosphates in general are not particularly user friendly of pesticides. So wearing protective clothing and spraying in a ventilated area is a good idea. As malathion is not systemic I normally spray and dunk the affected plants as Charles recommends.

I tend to use imidacloprid (Merit) before I turn to the organophosphates. It usually works well but don't find it as affective as malathion or dimethoate. I've have limited success with soaps and oils. I've had no success with spot applications of alcohols (it's a bit like swatting a wasp to get rid of the nest). What ever you use repeat the treatment at 3 day intervals for a week or two as many pesticides don't kill all stages in the life cycle.

Jerry Delaney · #10 06-16-2008, 03:30 AM

Quote:

Originally Posted by Ray

Spraying will be of little value, as Jerry stated that they were also in the root system - and root mealies are some of the toughest critters to eradicate.

Get yourself a good commercial insecticide - I recommend Orthene or Merit - and in addition to thoroughly wetting the entire surface of all of your plants (not just the ones apparently affected), fill the pots with the solution as well. Repeat several times per the label directions.

I agree with Ray. I have used Orthene for a number of years. Just a quick note. If possible, be sure to get the water soluble powder (usually 75%, 97% or 99%) of Orthene. This powder is readily soluble in water and will not harm plants or blooms. The liquid Orthene will work as well, but will damage any flowers and occasionally do some damage to new growths. This is due to the vehicle carrier, not the Orthene. Since this insecticide is so water soluble, I doubt that after a few flushing with water or water/fertilizer that there will be no problems with residual insecticide in the LECA. Also, once diluted in water, there is limited stability of the insecticide.