Combination Of Permethrin Research Articles

Occurrence of Pyrethroid Resistance in Pear Psylla (Homoptera: Psyllidae) Populations from Southern Ontario

Adult pear psylla, Cacopsylla pyricola Foerster, from the Niagara peninsula of Ontario were tested for susceptibility to pyrethroid insecticides from 1980 to 1989. A Potter spray tower was used. Results of tests at IS, 22, and 30°C indicated a negative temperature-toxicity relationship for permethrin and fen vale rate. Resistance to pyrethroids (first discovered in 1986 at levels of approximately 50-fold for permethrin at the LC50) has become widespread in the Niagara region. Resistance extends to all types of pyrethroids but is highest to fenvalerate (approximately 140-fold). Combinations of permethrin and potential synergists piper only but oxide or DEF did not increase the toxicity to resistant populations, suggesting that resistance was due to an insensitive target site or kdr-like mechanism. In one resistant population studied over 4 yr without further selection with pyrethroids, resistance declined from 54-fold to approximately 3D-fold after 1 yr and stabilized at 20-30-fold.

Mortality of Honeybees (Hymenoptera: Apidae) Exposed to Permethrin and Combinations of Permethrin with Piperonyl Butoxide

SummaryA laboratory study was conducted to test the pyrethroid insecticide, permethrin, separately and in combination with piperonyl butoxide (PB) at ratios of 1 part insecticide to 4 and 9 parts PB. Foraging honeybees, Apis mellifera L., were exposed to treated filter paper to determine toxicity and synergistic effects between the binary mixtures. Mortality was recorded 48 h after treatment. Permethrin used alone was highly toxic to the bees. PB synergized permethrin at both ratios, increasing the efficacy of permethrin, 9-fold. Combinations of permethrin and PB may merit testing in field situations to determine the actual hazard to honeybees.

Pyrethroid-synergist mixtures: toxicity, resistance and field efficacy toward pyrethroid-resistant horn flies (Diptera: Muscidae).

Permethrin and cyhalothrin in combination with piperonyl butoxide (PB), DEF (S,S,S-tributyl phosphorotrithiolate), pirimiphos-ethyl and -methyl were evaluated in the laboratory and the field for activity against pyrethroid-resistant and susceptible horn flies, Haematobia irritants (L.). Horn fly adults from the pyrethroid-resistant population were resistant to permethrin (12.5-fold) but displayed a lower level of resistance to cyhalothrin and cyhalothrin-K (5.4- and 1.7-fold, respectively). Combinations of permethrin plus PB or DEF or both produced a low level of synergism (1.4 to 4.6-fold) but did not reduce the level of resistance present in the pyrethroid-resistant horn flies. The levels of synergism (2.0- to 6.6-fold) observed for combinations of PB, DEF, and PB + DEF with cyhalothrin were marginally higher than for permethrin. Unlike permethrin, the combination of cyhalothrin + PB + DEF resulted in a decreased level of resistance. Pirimiphos-ethyl and -methyl were highly toxic to the horn fly, with virtually no cross-resistance in the pyrethroid-resistant population. Mixtures of pirimiphos-ethyl plus either permethrin or cyhalothrin were highly effective against the resistant horn fly population, but no more so than pirimiphos-ethyl alone. Field studies in 1985 demonstrated that, although the combination of permethrin + PB + DEF was more effective than permethrin alone, control was still inadequate. In these same studies, cyhalothrin provided marginal control while cyhalothrin + PB + DEF produced good results. In 1986, the use of cyhalothrin-K and pirimiphos-methyl resulted in excellent control of the horn fly throughout the season, as did a higher concentration of cyhalothrin and cyhalothrin + pirimiphos-methyl.

Interaction Studies of Methyl Parathion, Carbofuran, Permethrin, and Piperonyl Butoxide Applied to Southwestern Corn Borer Larvae (Lepidoptera: Pyralidae)

Binary mixtures of two different ratios (4:1, 9:1) of methyl parathion with piperonyl butoxide or with permethrin, carbofuran with piperonyl butoxide or permethrin and permethrin with piperonyl butoxide were applied topically to the third instar south-western corn borer ( Diatraea grandiosella Dyar). A synergistic (i.e., significantly greater mortality than that predicted by the hypothesis of independent joint action) interaction resulted from the combination of carbofuran plus either permethrin or piperonyl butoxide at both the 4:1 and the 9:1 ratios. Synergism was observed at the 9:1 ratio of methyl parathion plus permethrin or piperonyl butoxide. The 4:1 combinations of methyl parathion plus permethrin and piperonyl butoxide resulted in an antagonistic (i.e., significantly less mortality than that predicted by the hypothesis of independent joint action) interaction. Antagonistic interactions also were observed with combinations of permethrin plus piperonyl butoxide at both ratios. These results suggest that the combinations of carbofuran plus either piperonyl butoxide or permethrin and the 9:1 combination of methyl parathion plus piperonyl butoxide or permethrin might profitably be tested in actual field situations.

Toxicity of the insecticide permethrin and some degradation products towards algae and cyanobacteria

Toxic effects of the pyrethroid insecticide permethrin and ten of its degradation products were determined for the growth, photosynthesis and acetylene-reducing ability of two species of green algae and three species of cyanobacteria (blue-green) algae). Permethrin was relatively non-toxic in all systems, except for the growth of the cyanobacterium Anabaena inaequalis, where it had an EC 50 of 1·5 to 5·0 ppm (μg ml −1). From two to five of the degradation products were significantly more toxic than permethrin. The most toxic metabolites were 3-phenoxybenzaldehyde and 3-phenoxybenzyl alcohol, followed by benzoic acid, 3-hydroxybenzoic acid and 3-phenoxybenzoic acid. The EC 50 values of these compounds were as low as 1·4 ppm, although most were in the range 30 to 70 ppm for photosynthesis and acetylene reduction and 2 to 6 ppm for growth. The green algae were generally less sensitive than the cyanobacteria to these toxicants. Combinations of permethrin and selected metabolites were tested against A. inaequalis and yielded both synergistic, antagonistic and additive interaction responses, depending upon the actual test system.