Elimite
Toxicity of pyrethroids and effect of synergists to larval and adult Helicoverpa zea, Spodoptera frugiperda, and Agrotis ipsilon (Lepidoptera: Noctuidae).

Usmani KA, Knowles CO.

Department of Entomology, University of Missouri, Columbia 65211, USA. kusmani mailcity.com

Based on 48 h LD50 estimates from topical bioassays, cypermethrin was more toxic than permethrin to Helicoverpa zea (Boddie) larvae and adults; however, the two pyrethroids did not differ significantly in their relative toxicities to Spodoptera frugiperda (J. E. Smith) and Agrotis ipsilon (Hufnagle). Larvae of each species generally were more susceptible to cypermethrin and permethrin than respective adults. The only exception to this generalization occurred with H. zea where slight overlap of the 95% confidence intervals with larvae and adult males was observed with cypermethrin. Respective males and females of the three species usually did not differ significantly in their susceptibility to either cypermethrin or to permethrin; however, with A. ipsilon, females were more susceptible to permethrin than to cypermethrin. Several instances of greater than additive toxicity were noted when insects were treated with piperonyl butoxide, S,S,S-tri-n-butyl phosphorotrithioate (DEF), or amitraz 30 min before cypermethrin. DEF exhibited the broadest spectrum of synergistic activity.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11561845&dopt=Abstract permethrin Elimite



Elimite
Fate of permethrin in model outdoor ponds.

Rawn GP, Webster GR, Muir DC.

In 1979 and 1980, outdoor artificial ponds were treated with 14C-permethrin (labelled at either the cyclopropyl or methylene position) at 0.028 kg/ha (15 ug/L). Uptake of permethrin by duckweed and hydrosoil was monitored by direct combustion, TLC-autoradiography, HPLC, and liquid scintillation counting. Rapid loss of permethrin from the water coincided with the detection of five degradation products in the water at concentrations below 2.0 ug/L. The products were cis- and trans-cyclopropyl acid, phenoxybenzoic acid, and phenoxybenzyl alcohol, and an unknown non-cleaved product of permethrin. Permethrin was readily sorbed by duckweed but was not persistent. Permethrin residues in the hydrosoil, which was the major sink for permethrin added to the ponds, were persistent and were detected at 420 days post-treatment. Cis-permethrin was more persistent in the hydrosoil than the trans-permethrin. The results indicated that permethrin in water was short-lived at an application rate of 15 ug/L because of the rapid degradation of permethrin in the water and sorption of permethrin by the hydrosoil and vegetation. However, at one year post-treatment, permethrin residues were still detected in the hydrosoil at 1.0 ug/kg.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7175097&dopt=Abstract permethrin Elimite



Elimite
Effect of pyrethroid insecticides on soybean and its pathogen Rhizoctonia solani Kuehn.

Tu CM.

Laboratory tests were conducted to determine the phytotoxicity and fungitoxicity of five pyrethroid insecticides; cypermethrin, decamethrin, fenpropanate, fenvalerate and permethrin at different rates to soybean and its pathogen Rhizoctonia solani Kuehn. Fungitoxicities of the chemicals on pathogen were in the order of thiram greater than permethrin greater than cypermethrin greater than decamethrin greater than fenvalerate. Phytotoxicities on soybean seedlings were decamethrin greater than cypermethrin greater than fenpropanate greater than fenvalerate greater than permethrin greater than Arasan. A comparative study on both phytotoxic and fungitoxic effects indicated that the pyrethroids were less effective than Arasan for use in the control of this soil borne plant pathogen.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7200104&dopt=Abstract permethrin Elimite



Elimite
Use of insecticide-impregnated ear tags for the control of face flies and horn-flies on pastured cattle.

Williams RE, Westby EJ, Hendrix KS, Lemenager RP.

Three studies were conducted to evaluate the effectiveness of insecticide-impregnated ear tags in controlling face flies, Musca autumnalis DeGeer, and horn flies, Haematobia irritans (Linn.), on pastured beef cattle. In one 16-week trial, polyvinyl chloride (PVC) ear tags treated with stirofos (Rabon) insecticide reduced horn fly numbers by 79% (P less than .05) and face fly numbers by 30% (P less than .05). Coumaphos (Co-Ral) insecticide dust bags used in a separate herd produced an 86% (P less than .05) reduction in horn flies and an 18% (P less than .05) reduction in face flies. In the second study, 5 and 10% permethrin (Atroban), PVC-treated ear tags in a one-piece design were tested. In this 11 week trial, horn fly control averaged 95% (P less than .05) with the 10% tag and 77% (P less than .05) with the 5% tag. Face fly control averaged 49% (P less than .05) for 8 weeks with the 10% permethrin tag. No significant face fly control was achieved with the 5% permethrin tag. In a herd treated with coumaphos dust bags, horn fly control averaged 93% (P less than .05) and face fly control averaged 34% (P less than .05). The third study tested 5 and 10% permethrin, PVC-treated ear tags in a two-piece design and two-piece 5% permethrin-treated ear tags in a polyurethane matrix. Fourteen-week horn fly control averaged 88% (P less than .05) with the 10% PVC-treated tag, 83% (P less than .05) with the 5% PVC-treated tag, 71% (P less than .05) with the 5% polyurethane-treated tag and 74% (P less than .05) with coumaphos dust bags. Face fly control averaged less than 50% (P greater than .05) throughout the trial with all treatments.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7319964&dopt=Abstract permethrin Elimite



Elimite
Field trials to assess the efficacy of permethrin for the control of flies on cattle.

Bailie HD, Morgan DW.

Permethrin [3-phenoxybenzyl (+/-) cis, trans--2,2dimethyl-3-(2,2-dichlorovinyl) cyclopropane-1-carboxylate], a new synthetic pyrethroid, was applied to cattle on farms in the United Kingdom to assess its efficacy in fly control under field conditions. When 250 ml 0.1 per cent permethrin was applied to the backs of cattle using a knapsack sprayer, adequate control of horn flies, Haematobia irritans, was achieved for over three weeks. Application of 500 ml 0.1 per cent all over each animal gave one to two weeks' control of stable flies, Stomoxys calcitrans, and satisfactory control of non-biting flies for one week. Application of permethrin through a spray arch, using approximately one litre 0.05 per cent permethrin for each animal, gave similar control.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7445329&dopt=Abstract permethrin Elimite