pesticides >> Insecticides >> Thiamethoxam

Thiamethoxam (751)

Insecticide

neonicotinoid

NOMENCLATURE

Common namethiamethoxam (BSI, pa ISO)

IUPAC name3-(2-chloro-1,3-thiazol-5-ylmethyl)-5-methyl-1,3,5-oxadiazinan-4-ylidene(nitro)amine

Chemical Abstracts name3-[(2-chloro-5-thiazolyl)methyl]tetrahydro-5-methyl-N-nitro-4H-1,3,5-oxadiazin-4-imine

CAS RN[153719-23-4]Development codesCGA 293343 (Ciba-Geigy)

 

PHYSICAL CHEMISTRY

Mol. wt.291.7M.f.C8H10ClN5O3SFormCrystalline powder.M.p.139.1 °CV.p.6.6 ´ 10-6mPa (25 °C)KOWlogP = -0.13 (25 °C)Henry4.70 ´ 10-10Pa m3mol-1(calc.)SolubilityIn water 4.1 g/l (25 °C).

COMMERCIALISATION

HistoryDiscovered by Ciba (now Syngenta AG) in 1991. Reported by R. Senn et al. (Proc. Br. Crop Prot. Conf. - Pests Dis., 1998, 1, 27). Introduced in New Zealand in 1997.PatentsEP 580553ManufacturersSyngenta

 

APPLICATIONS

BiochemistryAgonist of the nicotinic acetylcholine receptor, affecting the synapses in the insect central nervous system.Mode of actionInsecticide with contact, stomach and systemic activity. Rapidly taken up into the plant and transported acropetally in the xylem.UsesUnder develoment for control of aphids, whitefly, thrips, ricehoppers, ricebugs, mealybugs, white grubs, Colorado potato beetle, flea beetles, wireworms, ground beetles, leaf miners and some lepidopterous species, at application rates from 10 to 200 g/ha (R. Senn et al., loc. cit.). Major crops for foliar and soil treatments are cole crops, leafy and fruity vegetables, potatoes, rice, cotton, deciduous fruit, citrus, tobacco and soya beans; for seed treatment use, maize, sorghum, cereals, sugar beet, oilseed rape, cotton, peas, beans, sunflowers, rice and potatoes.Formulation typesFS; GR, SC, WG, WS.Selected tradenames:'Actara' (foliar and soil treatments) (Syngenta); 'Cruiser' (seed treatment) (Syngenta)

OTHER TRADENAMES

'Adage' (USA) (Syngenta); 'Platinum' (USA) (Syngenta) mixtures:'Helix' (+ difenoconazole+ fludioxonil+ metalaxyl-M) (Syngenta)

MAMMALIAN TOXICOLOGY

OralAcute oral LD50for rats 1563 mg/kg.Skin and eyeAcute percutaneous LD50for rats >2000 mg/kg. Non-irritating to skin and eyes (rabbits); not a skin sensitiser (guinea pigs).InhalationLC50(4 h) for rats >3720 mg/m3.Toxicity classWHO (a.i.) III

ECOTOXICOLOGY

BirdsAcute oral LD50for bobwhite quail 1552, mallard ducks 576 mg/kg. Dietary LC50for bobwhite quail and mallard ducks >5200 mg/kg.FishLC50(96 h) for rainbow trout >100, bluegill sunfish >114, sheepshead minnow >111 mg/l.DaphniaEC50(48 h) >100 mg/l.AlgaeEC50(96 h) for green algae >100 mg/l.Other aquatic spp.LC50(96 h) for mysid shrimp 6.9 mg/l; EC50(96 h) for Eastern oyster >119 mg/l.BeesLD50for honeybees (contact) 0.024 mg/bee.WormsLC50(14 d) for Eisenia foetida >1000 mg/kg soil