It's the end of the season here but my cuke plants had a helping hand on the way to the rubbish bin. I noticed that the leaves were turning yellowish in-between the "ribbing" and "veins" on the leaves--a sign that more often alerts me that the plant is not getting enough to eat, in particular--Mg. I wasn't too worried because the plants have performed very well this year in the greenhouse. I was almost ready to pull the cukes out anyway, but then just out of curiosity, I had a closer look. It isn't something that I think about during rainy and cool weather, but in a greenhouse, apparently the conditions were good enough for it to do well, as several leaves were affected. Now, even though it is late in the season I want to take swift action to rid the greenhouse of these parasitic pests. Not only do I want to rid myself of these little beasts, but I thoroughly checked the paprika's and toms which were sharing greenhouse space with the cucumbers as well. It's the end of the season here but my cuke plants had a helping hand on the way to the rubbish bin. I only had to back light the leaf and immediately I saw that it wasn't an elemental short coming, but rather the Tetranychus urticae. I might have known. We call it "spint" here, but it is known in english speaking countries as the "red spider mite". I am hoping that you can see the web and the small bodied mites located in the notch between the two bulbous formations at the base of the leaf where the stem emerges. These mites are also easily seen at places where there are small branch-off from main stems and where the leaf stems branch off from twigs. The question is always, how to treat these mites. There are choices. 1)--Obviously you can purchase commercial poisons which can be applied either topically or systemicly. Because the mites have developed a resistance to some chemicals over the years, it might not be a bad idea to rotate the brands (chemicals) used in a course of treatment. 2)--You can also make your own version of less toxic concoctions: --I use a dollop of detergent and a jigger of white spirits mixed into a liter of tap water. Then I spray this onto the plants and repeat it every three days until all signs of mites are gone. mite infestation and presence exists in several stages, so in order to be successful in your Rx, then you have to treat more than once. This solution bio-degrades within four days. --You could use clipped and crushed stinging nettles in tap water, sieved and then sprayed onto the leaves and mites. --You can also introduce predators such as ladybugs, pirate bugs or the red-coloured Phytoseiulus persimilis. --Additionally, I remove the yellowed leaves that have been wasted by the mites, as they will never make a come-back and the plant's energy can go to supporting the healthy leaves that will remain and form once the treatment has been completed. --As always, prevention is better than trying to treat the problem. Misting to keep the plants moist and cool is a good start because the mites do not like moist conditions, nor coolness. They prefer hot and dry conditions. You could use plain water, but I often use comfrey and nettle "tea" or MgSO4 solution for feeding my plants topically, so this kills two birds with one stone: It feeds the plants AND makes the plant's milieu moist and cool at the same time. I hope that you guys do not have to deal with this pest, for it can be quite difficult to eradicate if left to infest in an unbridled manner. They can be present on outdoor plants, greenhouse plants or house plants. Keep an eye out for it.
Oh, I had the same problem this year. The eggplants hardly had a fruit on them until now and now people aren't wanting eggplant. I did the dishsoap spray only I burned them. Then I tried DE and that seemed to help, but the weather has made the biggest impact on them I guess. Even though they are in the high tunnel they seem to be doing better since we have gotten some rain. I did sprinkle garden sulfur on them too and they finally bounced back. The flea beetles were just as bad for me this year on the eggplants, too. I just couldn't keep up with them....ever so frustrating, eventually all the outside plants were lost to the pressure of the insects. sigh. I will try again next year.
My sympathy Sjoerd, but does some of your "liquors" really work??? I tried insecticides, water with dishwash... nothing worked. Spider mites kept strolling on the leaves like they had no worries at all. I am dealing with them on potted plants. In my apartment. So I cant really take them outside, see what works better. You know, I've got furniture, a tv, etc I just spotted these mites on a gardenia which I thought was pest-free. And I always check my adeniums - I know they are loved by mites, too.
Cal, if you aren't eating the plants that have the mites I would recommend using a systemic insecticide. I know we don't like to be using synthetic chemicals everytime we turn around, but for house plants I think it is imperative in order to have healthy houseplants. Imiclodiprid products seems to be about the most effective, but read the label. I finally resorted to a rose fertilizer/insecticide to control the mites on my Angel Trumpet Otherwise I wasn't able to get rid of them and I don't want to bring them in the greenhouse over the winter.
It was a horrible year for spider mites here this year too...they were on just about EVERYTHING in one section in the garden and nothing seemed to control them.
Thanks for your note, CAROLYN. I see that you have had your probs there as well. Well, it looks as if you are just getting a handle on things there, not that the season is winding down--typical, isn't it? Tch! I hope things go better for you next year. Thanks CALIN--Well, my concoctions do work for me. Luckily though the spider mite attack has occurred late in the season and so nothing was lost. It was time to take the plants out since it is way too cool for them to produce more fruits. There are flowers, but their will never make it to maturity. BTW--I agree with what Carolyn has to say about using a systemic Rx for your house plants. In fact, when I get mites or aphids on my house plants, that is exactly what I do with great success. It is a good idea to check out those other plants like you said that you were going to do, as those mites can float over to them. I hope that you can win the battle with these pests. Sorry to hear that mites was a problem there as well, NETTY--I sure hope that you can get on top of the mites there before the season changes and they go into dormancy until the spring. Treating your flowering plants ios such a dangerous thing to do in terms of the butterflies and bees that visit these plants. You are between a rock and a hard place there, so to speak.
Thanks! Well, Problem is over here in Romania we have different "stuff". This "Imidacloprid" I've never heard of. Other names it goes by are "Gaucho, Mallet, Merit, Nuprid, Prothor, Turfthor, Confidor, Conguard, Hachikusan, Kohinor, Optrol, Premise, Prothor, Provado, Intercept, Winner, and Xytect" I've only heard of CONFIDOR over here. I have used twice in the past 2 weeks MOSPILAN ... Either the concentration was wrong, or it didn't kill them, or it killed the adults but nw babies from eggs emerge... Oh well, I'll keep FIGHTING! Yesterday I was walking, I saw a small red ladybug on the pavement, I walked it by, turned around, picked it up in my fist and brought it home. I don't know what went wrong, it kept falling off the plant I put it on... Forgot to check this morning. You see? I am fighting with all weapons I can get!
Hello Mate, That Confidor in also available here and has the chemical name of imidacloprid. So, it is the same stuff. Man, I hope that you use that stuff (if you are going to use it) only indoors, as it is very poisinous to bees and birds. Ladybugs are helpful predators, but if you place them on a plant that was treated with imidacloprid (whatever its proprietary name may be), it could kill that bug. Mospilan is chemically known as Acetamiprid. It is a fairly strong insecticide and is harmful to bees. It is a neonicotinoid when has been linked to causing all sorts of problems for honey bees. I do not know what the correct dosage of this is but I wonder how often you can safely use it. If your house plants are infected with the mite, it may be the only thing that will work for you. You will need to use it more than once though the kill-off the new groups that hatch out. I hope that you can win this battle. Good luck, mate. Addendum: I just happened to think of something that is available here and perhaps in Rumania as well--they are little soft cardboard arrows, impregnated with a systemic insecticide. You just push several of these pins into the root ball of your house plant and water it. The insecticide is released and the hair roots of the plants take it up and into their circulatory system. When the parasites suck the sap, they take in the poison and die. This is mean, but effective.
