Cody, and OGD Readers... > Despite it's cost, Avid is a very good miticide. It is translaminar, meaning > that it is locally systemic. Good coverage of at least the upper leaf surface > will work on mites, the A.I. (active ingredient) will be absorbed by the leaf > and will translocate to the other side of the leaf (upper to lower). Cody, well said. I should start by saying I manage an extremely diverse array of tropical plants -- including orchids -- in a greenhouse setting for a plant wholesale company. I have found that Avid works on most mites in a population most of the time when used alone. This means, that on a re-spray, I will need to rotate to another chem in a different MOA class to avoid building resistance. I can achieve a near-100% kill when Avid is tank mixed with either Safers Insecticidal Soap or horticultural oil, the former preferred over the latter. Mixed together, the two chemicals work far better than either does separately. Coverage with the Safers mix is easier due to it's surfectant properties. The oil mix has fairly good coverage, but requires constant agitation to keep the oil in suspension. On small, localized populations, I will use a Safers/Oil mix. This particular blend is fairly effective on just about everything, including mealy, aphids, scale, whitefly, thrip, spider mites. Repeated applications do not build resistance, coverage is good, and there is low toxicity to both plants and humans.
I attended a series of seminars this summer on topics of this nature and others relating to the grower end of the floral industry. One such seminar was on the Q-biotype whitefly. This is a mutated version of the common whitefly we all know. What stood out in the discussion was that growers should focus less on eradication, and more on control (of course, this after prevention). It appears that when the population is under greater pressure, i.e. regular spray attempts at eradication, it more quickly will mutate to the dreaded Q-biotype. When populations of Q-type are under less pressure, they actually revert back to their earlier types. How do I feel about control versus eradication? Considering the diversity of the plants in my charge, I prefer NO BUGS over SOME BUGS. I think most of us feel this way. For example, I get excited when a shipment of ficus benjamina arrives infested with cuban laurel thrip. I want it gone immediately. While it appears that they prefer the ficus, I don't want to deal with them developing tastes for other species. And the way they prey on ficus requires lots of man-hours to remove them by hand and then spraying the plants. (For those of you unfamiliar with this problem, cuban laurel thrip insects will inject an enzyme into the midvein of a healthy ficus leaf that causes it to fold up and close into what I call a pod. The insects inside now have a protected, dark environment that is perfect for laying eggs and rearing young. No amount of spraying will penetrate these pods. They have to be removed by hand, and the plant sprayed and drenched to kill any thrip that may have migrated to the soil.) As you can imagine, eradication is a high priority in this instance for economical reasons. The good news is that of all the various plants in the greenhouse at any given time, I have virtually no pest problems with orchids. Oh, sure, there is a mealy or two now and then, and a few cyms this summer had a small bout with spider mites. And once last year, I found some black aphids on a few orchid flowers, but I think they came from a nearby pothos hanging basket. Other than that, in the past two years, that's it. In a mixed greenhouse, that is not the case with other tropical houseplants. Many varieties are very prone to specific pest attacks. For example, ivy. We inspect that regularly for spider mites. Others that are spider prone are dieffenbachia, croton, nepthytis, any palm, schefflera, pothos, english and algerian ivy and others. The same is true for each of the common pests we are always on the lookout for. Our philosophy is constant turnover. The less time you have a plant in your care, the less the chance you will have to deal with a pest problem. This makes isolating incoming products difficult, if not impossible. This means that complete inspection of incoming product is crucial. As for orchids, it is not always fast turnover. Yes, we buy in spiked plants to finish and ship out. But I am not always good at guessing how many to buy in and often have leftovers to rebloom later. And there are always a few mishaps with broken spikes, or plants damaged in shipment or that do not pass my quality inspection upon arrival that will have to be grown on. I have tried marketing non-blooming plants but the general public is not enamored of an orchid plant out of bloom. So, I usually have a couple of thousand orchids on benches awaiting maturity. (And of course, my whole collection of plants, compots, etc. is there, too). I would like to hear from others about your experiences with pests and how your handled them in your orchid collection, both in the home and/or greenhouse. Best Regards, Barbara _______________________________________________ the OrchidGuide Digest (OGD) [email protected] http://orchidguide.com/mailman/listinfo/orchids_orchidguide.com
