Some effects of diazinon on the microflora of submerged soils
SummaryThe application of diazinon, an organophosphorus insecticide, at the rate of 2 kg and 20 kg active ingredient per hectare to submerged Maahas clay significantly stimulated the actinomycete population. A distinct zone of brown pigmentation formed in that part of the profile commonly referred to as the oxidized layer. A profuse growth of actinomycetes developed from the soil samples of this pigmented zone when streaked onto the nutrient agar. A visible increase in algal populations was noted in the standing water of the diazinon-treated soil.
Effects of Ekalux Ec-25 on akinete germination and sporulation ofPithophora kewensis
The effect of the organophosphorus insecticide Ekalux Ec-25 (quinalphos) was studied on akinete germination, and sporulation of the green algaPithophora kewensis (Cladophorales). Initiation of akinete germination was delayed by 1–3 d with 0.025–0.1% concentrations of the pesticide used. The percentage of akinete germination was found to be markedly affected by the treatment with insecticide, except with the concentration of 0.25% Ekalux Ec-25, where percent germination was observed to be higher than in the control. Generally, the time taken for the initiation of akinete formation increased and percent sporulation decreased with the increase of concentrations from 0.025 to 0.1% of Ekalux Ec-25.
Über ein neues Insektizid mit breitem Wirkungsspektrum
Es wird die Verwendung von Thiophosphorsäure-[2-isopropyl-4-methyl-pyrimidyl-(6)]-diäthylester (Diazinon) als Insektizid im Pflanzen- und Vorratsschutz und in der Hygiene beschrieben. Die akute orale Toxizität, DL 50 in mm3/kg Körpergewicht, beträgt an der Maus 96, an der Ratte 235, am Meerschweinchen 320, am Kaninchen 130. Die chronische Toxizität liegt z. B. an der Ratte günstiger als jene von Dichlordiphenyl-trichloraethan. Diazinon zeigt, wie andere Phosphorsäureester, eine starke Hemmung der Cholinesterase. Auf Insekten und Spinnmilben hat es eine Kontakt-, Fraß- und Gaswirkung. Auf Pflanzen appliziert, weist es wohl eine Tiefen-, aber keine systemische Wirkung auf. Aus den verschiedenen Applikationsgebieten ist vor allem die gute Wirkung gegen Lepidopteren und Dipteren hervorzuheben. Letztere ermöglicht den Einsatz von Diazinon zur Bekämpfung der resistenten Fliegen. The use as an insecticide for the protection of plants and stores of thiophosphoric acid [2-isopropyl-4-methyl-pyrimidyl-(6)]-diethylester (Diazinon) is described. Its hygienic use is also described. The acute oral toxicity, DL 50 in mm3/kg body weight, is, for the mouse 96, for the rat 235, for the guinea pig 320, for the rabbit 130. The chronic toxicity is more favourable, for example in the rat, than that of Dichlordiphenyl-trichlorethane. Like other phosphoric acid esters, Diazinon greatly inhibits cholinesterase. It acts as a contact, stomach and gas poison on insects and red spiders. Applied to plants it certainly has a deep, but not a systemic action. Of all the various possibilities for application, its good action on Lepidoptera and Diptera is of particular importance. Diazinon can thus be used for the control of resistent flies.