Fruitgirl is correct. Although the main organic certifying agency OMRI does somewhat take into account health risks. As I recall they currently don't allow Rotenone. Synthetic doesn't automatically mean safer either. There are some synthetic products that I would judge safer than some organic, and vice versa. It's really a judgment call that can include a lot of factors: acute toxicity, carcinogenic potential (which is also an issue for natural substances) reproductive issues, and of course the effect on the environment. Here is a site you can look up some of that info. for just about any pesticide. I' reluctant to post this site, because I think they are a bit alarmist. Their attitude seems, the only good pesticide is a banned pesticide. For instance, even the organic pesticide spinosad, they list as a possible endoctrine distruptor, and possible developmental toxin. Nevertheless, they do have some good hard data on each pesticide. Also residue levels can be an indication of toxicity potential. The Maximum Residue Levels Database are internationally accepted levels of pesticide residues on food crops, or in the case of the U.S., FDA accepted residue levels. For example, Spinosad has a Max residue level of 0.2ppm and Triazicide (gamma cyhalothrin)has a MRL of 0.5ppm. Of course there are other factors involved (i.e. how fast the pesticide breaks down) Organic pesticides generally break down faster which gives less of a residue, but also means it must be applied more frequently. Ultimately, you have to make the decision what to use, but to try to give some specific answer to your question, synthetic pyrethroids are considered one of the safer insecticides to humans, compared to other insecticides.

OK, I found out that they may have sprayed for gypsy moth, but they sprayed Btk (I assume that's what you were talking about) In October 2007, Council directed staff to hire an independent consultant to assist with Gypsy Moth egg mass surveying and to analyze the data collected. The March 17, 2008 report to the Public Works Committee provides an update on the degree of infestation of Gypsy Moth in the City and provides a program delivery strategy for CouncilÂs approval to mitigate the damage to the urban forest from Gypsy Moth in the areas surveyed and to limit the spread of the infestations to other areas. Staff prepared a report pertaining to the proposed Gypsy Moth control plan that was received by the Public Works Committee at its March 31, 2008 meeting and was approved with amendments by Hamilton City Council at its April 9, 2008 meeting. Aerial spraying recommended Due to the extent of Gypsy Moth infestation in the Hamilton area, aerial spraying of woodlots and parkland will be required. The City of Hamilton's Public Works Department, Hamilton Conservation Authority and the Royal Botanical Gardens (RBG) will be undertaking an aerial spray application of the biological pesticide Btk over areas of Ancaster, Flamborough, Dundas, Glanbrook and West Hamilton including parts of the Dundas Valley and Cootes Paradise. To be effective on Gypsy Moth larvae, two applications of the aerial spray application must take place in mid-May to early June. Open Houses The City of HamiltonÂs Public Works Department, Hamilton Conservation Authority and Royal Botanical Gardens held several Public Open Houses to allow members of the public to receive more information on the Gypsy Moth infestation problem in our area, the proposed control plans and what property owners can do to assist in the control of Gypsy Moth. So I think I can rule out city spraying affecting the bugs. Still a mystery.

Potassium bicarbonate, or "Green Cure", is 25% to 35% more effective than baking soda. "Green cure" is safe to spray on leaves. One guy in Colorado (dry climate) recommended "Green Cure" for mildew in HMF. Blendguy (Robert) who started the English Roses Forum, stated in this forum on Oct 5, '07: "I've been using it this year, and I've had very good luck in my garden ... I bought Greencure because I had heard so many horror stories of trying to grow "old" and "English" roses so close to the ocean (I've about 35). I've had very good success with it warding off and/or eliminating PM. I've had a very little PM, but nothing compared to my neighbors ... all seem to have PM everywhere in their gardens ... I've "heard" that the remedies for PM, like Greencure, might very well be less successful on BS. " Robert. Both potassium and calcium is needed for the integrity of cell membrane, to prevent fungal invasion. Folks report success spraying with diluted milk. Milk has calcium, plus salt. Salt also inhibits fungal growth. I prefer limestone as fungicide, since it's lowest in salt. My clay is dolomitic-limestone clay, high in magnesium. Dolomitic Limestone provides 25% calcium and 10% magnesium, salt index 0.8. Calcitic limestone provides 36% calcium when the rain water (pH 5.6) breaks it down, low salt index 4.7. Gypsum provides 22% calcium, 17% sulfur, with salt index of 8.1, used to de-salt sodic soil, also to neutralize bicarbonates in alkaline tap water. Lime sulfur was used in the old days as a fungicide, pH over 11.5, very caustic. Lime sulfur is made by reacting calcium hydroxide with sulfur. According to eHow: "Potassium bicarbonate is soluble in water. "Green Cure" is potassium bicarbonate, effective against mildew. Below is Wise Portia rose, prone to mildew, I gave it sulfate of potash NPK 0-0-50 and gypsum (calcium sulfate) for fungal-prevention. Here is a link that might be useful: Green cure (potassium bicarbonate) and mildew

There is definitely resistance to pyrethroids and pyrethrins in the flea world. However, saying that, 90% of the time when I hear clients say the product is 'not working' it is because the flea problem is so overwhelming that the pet is constantly getting a new population of fleas on it from the environment, and the product is actually working... just not as instantaneously as the client wants (sadly there is no such instantaneous flea killing product on the market). This is particularly common with Frontline as it takes an average of 48 hours from initial exposure to death, making owners very frustrated when they see fleas still running around on their dogs. All those fleas, as soon as getting on the dogs, will die (nearly 100% effective, and true resistance to a product like Frontline or Advantage are extremely rare)... the fleas just don't know it yet (and neither do the owners). Revolution is also equally effective but it can take up to 4 days for flea to die after exposure. It WILL die. But it takes a bit. This can still be true with the pyrethroid products, too, though those have been around for well over 30-40 years and true resistance has been proven... so determining lack of effect versus overwhelming repopulation with pyrethroids is very difficult. Anyway, since all fleas look alike, it is hard to track individual fleas to see if they are all dying or not, or are they just being replaced by new fleas? Studies done on fleas have often involved vet students (free slave laborers, in other words) actually tagging individual fleas (Not any easy task) and demonstrating that subsequent flea counts reveal fleas still present on pets, but not the SAME fleas... in other words, products are working well, but cannot keep up with the constant repopulation problems. In these cases, it helps to have owners treat the environments, too (bombs, environmental sprays, diatomaceous earth, professional exterminators etc.) or the flea problem will be very hard to get control of. As to your question about applying Frontline now, after applying a pyrethroid recently, is absolutely. No problem. Frontline is an extremely low toxicity to mammals and can even safely be applied daily- though this is rarely if ever indicated... but often we recommend, in severe infestations, to apply frontline or advantage 2-3x a month. And these two products are in a completely different class of chemicals than a pyrethrin so will not 'add to any toxicity' already going on (pyrethrins and pyrethroids are potentially much more toxic products for mammals). Just don't be depressed or surprised if the fleas do not die any faster (and probably they will actually die slower... but ALL will die... they just may get immediately replaced with new ones).