Category
Acaricides / Miticides > Pyrrole acaricides
Insecticides > Pyrrole insecticides
Activity
Acaricide/Miticide,insecticide.
Chlorfenapyr is a pro-insecticide. On assimilation by the pest, de-alkylation of the pyrrole nucleus occurs revealing the biologically active moiety. The compound is primarily a stomach poison but also has contact activity. Chlorfenapyr has excellent translaminar activity. Depending upon conditions, residual activity may last for more than two weeks. The company reports that there is no cross-resistance to commercially available products and that chlorfenapyr is safe to crops at the recommended rate. Chlorfenapyr is an excellent resistance management tool as a result of its novel mode of action.
Chlorfenapyr has been registered for use against Helicoverpa armigera on cotton in Australia since 1997 where it is part of the Australian Helicoverpa resistance management strategy. During the 1997/8 cotton season it was evident, however, that a low frequency of H armigera (3%) were resistant to chlorfenapyr and this figure progressively increased to approximately 17% in 2002 (BCPC, 2002). The speed with which H armigera larvae developed resistance was due to cross-resistance to high level pyrethroid resistance. Further studies indicated a common esterase mediated resistance mechanism between chlorfenapyr and pyrethroid resistance. Control of Tetrancychus spp on cotton is more effective than that provided by standard miticides and excellent control has been observed with dosages as low as 50 g a.i./ha. The duration of mite control is positively correlated with the application rate. The product does not increase the population in cotton aphids like that observed with pyrethroids.
Chlorfenapyr provided better overall control of insect pests on vegetables such as lettuce, cabbage and broccoli than the commercial standards Bacillus thuringiensis, chlorpyrifos, cypermethrin, diflubenzuron, fenvalerate, methomyl, permethrin and thiodicarb. Vegetable pests such as P.xylostella and L. decemlineataare resistant to conventional insecticides but are controlled by chlorfenpyr.
Chlorfenapyr provides exceptional control of B. phoenicis and Phyllocoptruta oleivora on citrus. Residual control after 60 days has been observed. The addition of spray oil enhances control at lower rates of chlorfenapyr against certain mites. Chlorfenapyr is effective against Lepidoptera species on soybean; it is highly effective on permethrin resistant soybean looper. Chlorfenapyr has shown activity against coffee leafminer at rates of 100-125 g active ingredient but at these rates the control provided was inferior to that obtained with the commercial standards deltamethrin and permethrin.
In laboratory and field studies, the addition of emulsified, petroleum-based oil to chlorfenapyr enhanced the foliar and contact activity of the compound against T.urticae.
Studies of the genetic basis of resistance to the acaricides, chlorfenapyr and etoxazole, which have different chemical structures and modes of action, have been conducted in the two-spotted spider mite, Tetranychus urticae (J. Econ. Entomol, 2002). The resistance ratios calculated from the LC50s of resistant and susceptible strains were 483 for chlorfenapyr and >100.000 for etoxazole. The mode of inheritance of resistance to chlorfenapyr was completely dominant as indicated by mortality caused by the two acaricides in F1 progeny from reciprocal crosses between the resistant and susceptible strains. As shown by the mortality in the F2progeny, the resistance was under monogenic control for both acaricides. Repeated backcross experiments indicated a linkage relationship among the two acaricide resistances and malate dehydrogenase, although phosphoglucoisomerase was not linked with them. The recombination ratio between the resistances was 14.8%. Heavy spraying of the two acaricides could, therefore, lead to cross-resistance as a consequence of crossing over as the two resistance genes are so close to each other that it would be difficult to segregate them once they came together on the same chromosome.
CropUse
Crop uses:
apples, aubergines, brassica, cabbages, Chinese cabbages, chrysanthemum, cucumbers, citrus, cotton, ground cherries, lettuces, ornamentals, peaches, pears, pepinos, peppers, persimmon, potatoes, tea, tomatilloes, tomatoes, vegetables, vines
| Cotton |
100-300 g ai/ha |
| Vegetables |
100-360 g ai/ha |
| Citrus |
18.35-62.41 g ai/ha |
| Ornamentals |
180-360 g ai/ha |
| Greenhouse fruiting vegetables |
110-230 g ai/ha |
Premix
Chlorfenapyr+Emamectin benzoate
Chlorfenapyr+Methoxyfenozide
Abamectin+Chlorfenapyr
Audited Supplier 
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