Concentrations Of Diazinon Research Articles

Evaluation of chemically controlling the collembolan Bourletiellahortensis on germinating Sitka spruce and western hemlock in the nursery

Three concentrations of the insecticides diazinon, fonofos, malathion, and oxamyl and one concentration of the herbicidal mineral oil Shell AWK No. 1® were tested on Sitka spruce [Piceasitchensis (Bong.) Carr.] and western hemlock [Tsugaheterophylla (Raf.) Sarg.] for controlling the collembolan Bourletiellahortensis (Fitch) in nursery trials in 1972 and 1973. All insecticides were effective against the insect, but low spring populations of the collembolan prevented full evaluation of the trials. A 4-m diazinon-sprayed surround was adequate to keep the insect from migrating to adjacent plots. Certain nursery practices, such as application of the herbicidal mineral oil Shell AWK, the herbicide propazine, and sodium fluosilicate for weevil control, temporarily suppressed B. hortensis populations but did not provide effective control against this insect. Shell AWK, applied when the radicle was emerging from the seed, was apparently phytotoxic to Sitka spruce.

The effect of atrazine, 2,4-D, methoxychlor, carbaryl and diazinon on the growth of planktonic algae

The effect of various concentrations of atrazine, 2,4-D (butoxy ethanol ester), methoxychlor, carbaryl and diazinon on the growth of 36 isolates of planktonic algae was studied. No genera toxicity of methoxychlor near saturating concentrations (0·01 p.p.m.) was demonstrated. The butoxy ethanol ester of 2,4-D was toxic to some test organisms at a concentration of 4 p.p.m. Atrazine inhibited growth generally at 1 p.p.m. and higher, and diazinon and carbaryl were toxic at concentrations of 10 and 25 p.p.m.

Immersion Technique for Measuring Susceptibility of House Flies and Cockroaches to Insecticides123

An immersion technique for exposing a large number of the house fly Musca domestica L., and the German cockroach Blattella germanica (L..), to measured doses of toxicants is described. Experiments showed that serial concentrations of DDT, dieldrin, diazinon, and malathion expressed as μg per ml elicit responses directly related to the concentration used. Reproducible results can be obtained by the method. Toxicants are dissolved in 10% acetone-water to which 1 drop of Triton X-100 is added to each 100 ml of solution.

Degradation of diazinon in soil

AbstractThe disappearance rate of diazinon in two different soils, at two levels of water content, with two different diazinon concentrations, and in steam‐treated and untreated soils has been studied. The rates of disappearance were measured by the slopes of the disappearance curves in a semi‐logarithmic coordinate system and by the corresponding half‐lives (RL50 in days) for each combination of the factors.The results were examined statistically, and it was found that all of the four factors influenced the degradation rate of diazinon in soil, the greatest effect occurring with steam‐treatment, i.e. caused by the micro‐organisms in the soils, and the least from the diazinon concentration. Interactions between some of the factors are demonstrated.

Effect of post-treatment temperature on toxicity of insecticides to resistant and susceptible house flies.

Laboratory and field strains of house flies. Musca domestica L., were treated topically with 1 µliter drops of either diazinon or lindane at various concentrations and held at post-treatment temperatures of 15 and 30°C. With 2 laboratory stains. a diazinon-resistant and a susceptible strain, treated with diazinon. mortality was higher at 30°C. Percent mortality differences between the 2 temperatures at the higher concentrations of diazinon indicated a temperature × diazinon interaction with the resistant strain but not with the susceptible. Mortality of the susceptible strain was similar whether held at 1 temperature for 24 hours or for 8 hours at that temperature plus 16 hours at a higher or lower temperature. Resistant flies held at 30°C for 8 hours plus 15°C for 16 hours showed similar mortality to flies held at 30°C for 24 hours. However, flies held at 15°C for 8 hours plus 16 hours at 30°C also showed a mortality similar to that for flies held for 24 hours at 30°C. With lindane there was significantly higher mortality at 30°C with the susceptible laboratory strain than at 15°C. There was no significant mortality difference between these temperatures with the diazinon-resistant strain. With a third strain, highly resistant to lindane, there was significantly lower mortality at 30°C than at 15°C. Flies collected from several dairy barns and treated topically with diazinon varied significantly in the level of resistance to diazinon, which variation could be correlated with the spray control program which had been conducted in each barn. Percent mortality differences between 15 and 30°C were significantly greater at the higher concentrations of diazinon and were largest with those fly populations showing a relatively high level of resistance.

Field studies of insecticides against the coffee leaf-miner Leucoptera meyricki Ghesq. (Lepidoptera, Lyonetiidae)

The coffee leaf-miner Leucoptera meyricki Ghesq. is the most serious insect pest of Coffea arabica in Kenya. Until recently, sprays containing parathion, methyl-parathion or diazinon have been recommended for its control.Field trials were carried out there during 1962 with these three insecticides and two others, fenthion and fenitrothion, that had shown promise in laboratory trials described in an earlier paper. The greater part of the investigation was carried out on the larval stage. Single-tree plots were used, arranged in randomised blocks, and sprays were in most cases applied by knapsack machines. Spraying in all trials was timed to coincide with the presence of large numbers of half-grown larvae. Suitable dates could be forecast because the generations of L. meyricki follow a denned cycle with a single stage dominant at any one time. Mortalities of larvae were assessed, four days after application of the insecticide, by dissecting freshly mined leaves selected at random. Where necessary, a spray of coarse droplets of a poison bait was applied before a trial in order to reduce populations of parasites and mortality due to them to a low level.At a concentration of 0·02 per cent., a spray of parathion gave a. significantly higher kill than one of methyl-parathion. Diazinon, fenthion and fenitrothion were available as emulsifiable concentrates containing 60, 55 and 50 per cent, active ingredient (w/v), respectively. These were tested at equivalent dilutions. At a dilution of 1¼ pints concentrate in 100 gal. water (affording concentrations of 0·094, 0·086 and 0·078 per cent, active ingredient, respectively), which was the volume per acre required to give full cover, fenitrothion gave a significantly higher kill than fenthion or diazinon, there being no significant difference between mortalities achieved by the latter two insecticides. The addition of a supplementary wetting agent to sprays of fenitrothion increased kill significantly, as did a reduction in spray volume with fenitrothion and parathion. The possible reasons for this are discussed.The field trials described generally confirm the results obtained in earlier laboratory tests and support the view that any insecticide which shows promise in the laboratory will also give good results in the field.A small-scale trial on potted seedling coffee plants was carried out to test by the dipping technique the ovicidal properties of concentrations of parathion, diazinon, fenthion and fenitrothion equal to one-half or two-thirds those necessary to give satisfactory field control of mining larvae. Mortality of eggs varied with their age, but in all tests with the first three insecticides it exceeded 90 per cent. In a comparison between fenthion and fenitrothion, the former was significantly more toxic than the latter, which killed only 38·1 and 82·1 per cent., respectively, of eggs ½ and 5½ days old.The correct timing of sprays against Leucoptera is very important and should follow about seven days after the peak of moth numbers.The insecticides used in these experiments are considered in the light of the characteristics, which are listed, that are desirable in those to be recommended for the control of Leucoptera on coffee. Those recommended, with rates (Ib. per acre), are parathion (0·4), fenitrothion (0·9) and fenthion (1·0). Diazinon and methyl-parathion are no longer recommended.