Update on Insecticides and Miticides for the Ornamental Market
I’ve been kidding around at some of the recent conferencesby polling the audience to determine its makeup. First, I ask how many in theaudience work in greenhouses, then how many work in nurseries or both sincemany nurseries have associated greenhouses. Lastly, I jest that what’s left ofthe audience must be the chem-reps. It seems like at every conference of late,most of the representatives of the chemical companies are there to give alittle speech about the latest products they have on the market forornamentals.
Mostly they concentrate on the fungicides, but occasionally they have a new or developing insecticide or miticide. Relatively few insecticides have been in development over the last few years, but there is hope on the horizon. I’m becoming aware of more compounds that are somewhat secret in nature, and if I told you about them I’d have to eliminate you. Well. . .they might eliminate me. However, that should provide you with some hope for the future. It is very important that the ornamental industry be provided with more alternatives for pest control. Resistance management begs for it.
Although you can see more reps at every conference, youmight not hear the same story every time. The companies themselves and labelshave been changing very rapidly. It’s easy to discuss what’s available here inCalifornia, but that will leave out a number of pesticides that are firstregistered everywhere else. I particularly like Ann Chase’s description of alist of fungicides she provided last year in her column. She said, “Themajority of the products included are currently labeled somewhere in the UnitedStates, though you should check the label to see if they are registered for usein your area.” I completely agree, and that’s the approach I will take inthis discussion.
Miticides
As you are probably already aware, there has been a flurryof new miticides in development over the past few years. Some of them arealready on the market. The following is a review of the most recent changes.
EPA registration for Tetrasan 5WDG (etoxazole) from ValentUSA and Ultiflora (milbemectin) from Gowan are expected this fall, hopefully bythe time this article is published. Tetrasan is a 5-percent WDG (waterdispersible granule) that can be used at 8-16 ounces 100 per gallon. It’s a newclass of miticide with a mode of action much like an insect growth regulator.Mites are not insects, but they still have to shed their skin to grow. Likeinsect growth regulators, they don’t kill adults, but are active on eggs andnymphs, and may sterilize adult females. Residual activity lasts between 21-28days. Ultiflora is a naturally derived, broad-spectrum miticide withtranslaminar activity. Like Avid (abamectin), Ultiflora also has activityagainst leafminers. Residual control is 21-28 days.
Floramite SC (bifenazate) has been around for awhile now asa wettable powder, but Uniroyal has developed an SC formulation. It already hasa federal label and some state labels. It has a better wetting agent in the SCformulation, and Uniroyal has been demonstrating better activity with the SCthan with the comparable WP. We’ve had similar results here at UCR againstLewis mite on poinsettia.
Akari 5SC (fenproximate) miticide from SePRO now has aninteriorscape label, formerly greenhouse-only for spider mites. Outdoorregistration is expected next year and SePRO is expanding the label to includeeriophyid and tarsonemid mites.
Insecticides
I won’t belabor the fact thatthe broad-spectrum pesticides of the past are dwindling at an ever-increasingrate. Last year, Dr. Dick Lindquist mentionedfenoxycarb and bendiocarb in this report. This year (2002),greenhouse use of Knoxout GH (diazinon) and Fulex Dithio Smoke/Plantfume 103(sulfotepp) were lost, and Nemacur (fenamiphos) will be phased out over thenext few years. Diazinon sales must stop by the end of this year. Sulfoteppproduction and sale were to have been terminated by September 30 this year, anduse must stop September 30, 2004. In spite of the bad news, the outlook isstill promising because a number of new insecticides have been underdevelopment in the last few years and some are now available. The only downsideis that they have a somewhat narrower spectrum of activity.
IGRs
Pedistal 10 SC (novaluron) is anew product from Uniroyal. It is considered a benzopheny urea much like diflubenzuron.It acts the same way too, as an IGR or a chitin synthesis inhibitor. It isexpected to reduce the reliance on OPs, has low mammalian toxicity, and isconsidered to be a low risk to the environment and non-target organisms. It hasactivity against thrips, whitefly, lepidoptera and leafminer. An earlierversion called Rimon 10EC received the federal and state labels first but wassubmitted for greenhouse use only. Uniroyal resubmitted for greenhouse,nursery, landscape, Á interiorscape and shadehouse use, and the SCformulation should be available sometime this fall.
Another IGR making its way intothe market is Talus Insect Growth Regulator (buprofezin 70%) from SePRO Corp.It is a new insecticide for control of immature stages of whitefly, scale, mealybugand leafhoppers. It is also a chitin synthesis inhibitor, so it affects theinsect as it molts. The initial registration will be for outdoor use.
Chloronicotinyls
Flagship 25 WG (thiamethoxam) isanother insecticide of the chloronicotinyl class that’s under development bySyngenta. It has excellent activity against aphids, whiteflies and mealybugs onornamentals as well as grubs, billbugs and chinch bugs in turf. This producthas flexibility of application including drench, irrigation and foliar. Registrationis pending.
Here’s another merger you shouldbe aware of. Bayer Corporation is now known as Bayer Crop Science to merge thetwo company names of Bayer Corporation and Aventis Crop Science. They aredivesting a new product called Tristar 70 WP (acetamiprid), which has greatpromise for the greenhouse, nursery and landscape industries. Like Flagshipmentioned above, it is a new chloronicotinyl class insecticide. Its fate is notyet known, but it is sure to become a usable product for the future. It receivedreduced-risk status from the EPA, and it is expected to be available this year.Bayer Crop Science is also developing another chloronicotinyl calledthiacloprid 480 SC. It is softer on non-target organisms, but the spectrum isbroader to include some microlepidoptera (small moths), which are very smallmoths for the non-entomologist. Registration is not going to happen for awhile.
New Chemistry
FMC is developing a new productfrom ISK Biosciences called Flonicamid. It will be registered for greenhouse use on ornamentals. Flonicamid 50 WG isconsidered an OP replacement and received reduced-risk status, which usuallystreamlines the registration process. Flonicamid is systemic and suppresses thefeeding of sucking insects. At the moment, the mode of action of this chemicalis unknown; however, it appears to be unique. We look forward to testing thisnew compound here at the university.
An Old Standby
For those of you folks inCalifornia, Mesurol 75W from the Gowan Company is now registered indoors andoutdoors as a sprayable insecticide and molluscicide. It has a broad spectrumof activity, especially against western flower thrips, snails and slugs. Gowanis also introducing Mesurol Pro, which is a new bait formulation of the productfor use indoors and outdoors against snails, slugs, sowbugs and millipedes.Both products can be used in ornamental production and landscape areas.
Finally
One trend that’s picking upmomentum is testing the compatibility of the newer, narrow-spectrum pesticideswith biological control agents. Biological control was much more difficult inthe past because of the consistent use of broad-spectrum insecticides andmiticides. However, there are more and more examples of successful biologicalcontrol of ornamental pests when used in an integrated pest management program.With the narrower spectrum of activity of the pesticides and the pestmanagement restrictions on the label, many in the industry want to know thetoxicity of their products against the more common biological control organismssold commercially. The use of alternatives like biological control and IGRsearly in a cropping cycle for some ornamentals will also prolong the efficacyof these newer pesticides.
I know that pesticide rotationmay be a confusing issue to some. To start with, pesticide rotation shouldoccur by chemical class, and there’s plenty of published information now onpesticide chemical classes, but not much yet on what to start with and which torotate to. A proper rotation scheme will most likely have to be designedspecifically for each pest and host. As a simple example, there are not manypesticides to rotate amongst when trying to control the leafminer onchrysanthemums. Using an IGR like Citation early, possibly in combination witha parasitoid, will delay any chance of resistance buildup in the greenhouse.IGRs are compatible with many beneficials because they are usually deployed asadults, which are not susceptible. Following the IGR, a rotation to a moreconventional pesticide like a pyrethroid or OP followed by Avid in the laststages of the crop is a good rotation scheme. More to come.
There. . .now I’m going to goout and see if I can find some nice, early, pest-free, Thanksgiving Daypoinsettias. Happy holidays!
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