Organophosphates acaricides

Disulfoton is a systemic insecticide/acaricide that belongs to the organophosphate class of pesticides. Pure disulfoton is a colorless oil with low volatility and water solubility, but is readily soluble in most organic solvents (Worthing 1987). Information regarding the physical and chemical properties of disulfoton is located in Table 3-2. 

Dimethoate Organophosphate 60-51-5 1.05 -1957 Insectic. An insecticide and acaricide used to control a wide range of pests including Aphididae, Coleoptera, and Lepidoptera... 

Note NA (data not available) OC (organochlorine insecticide) OP (organophosphate insecticide) PY (pyrethroid insecticide) A (acaricide). aData collected from northern part of Thailand. bData collected from eastern part of Thailand. 

Chronic toxicity of organophosphates may be discussed under four different areas carcinogenicity, delayed neurotoxicity, experimental myopathy, and, in humans, psychiatric disorders. In 1983, the IARC (International Agency for Research on Cancer) evaluated the carcinogenic potential of, among other pesticides, five organophosphate insecticides/acaricides (malathion, methyl parathion, parathion,... 

Treatment history is important for one species but not for another. However, were no other processes involved (e.g., migration or fitness), given the nearly 30 years of use of dicofol, we would expect all populations of P. ulmi. and T. urticae to be highly resistant to dicofol such a situation exists with the widespread and stable resistances of spider mites to organophosphate acaricides. Our second hypothesis, that migration of susceptible spider mites into orchards is responsible for differential susceptibility of populations, while very plausible for T. urticae, seems unlikely for P. ulmi, given the very limited availability of hosts for this species outside of commercial orchards in New York. 

The acaricidal activity of these formamidines is based on a mechanism which is entirely different from that of the chlorinated hydrocarbons, organophosphates and carbamates. Some of them are more toxic to organophosphate-resistant mites than to organophosphate susceptible ones (Dittrich, 1969). 

Insecticides accounted for 74% of the total agrochemical market value. Within this sector, organophosphates have 41% of the market by value, pyretliroids 20%, organochlorines 6% and carbamates 5%. Tlie remainder of the agrochemical market was represented by herbicides 14%, fungicides 9%, acaricides 2% and fumigants 1 %. 

Neurotoxic compounds have been traditionally the largest category of acaricides, with several representatives from the organophosphate, carbamate, and pyreth-roid classes. Several new pyrethroid compounds such as acrinathrin, lubrocythri-nate and halfenprox and an analog of the macrolide abamectin milbemectin were recently introduced as acaricides. A completely new acaricidal chemistry has been found with carbazate chemistry [1]. 

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