The Study Of Bioassay Methods On Beneficial Organisms Safety Evaluation Of Pesticides

The Study of Bioassay Methods on Beneficial Organisms Safety Evaluation of PesticidesThe testing conditions of beneficial organisms (honeybee, silkworm and fishes) safety evaluation on pesticides were studied. The results of the various testes are listed:Honeybee: The methods of Pro-treatment, sugar concentration, experimentation utensil, filling substance, the methods of bioassay and surface-active agents, these testing conditions had were proved that effects were remarked. The other way round, fodders, the time of illumination and the place of dropping had hardly effects of the testing results.Though optimizing the testing result, bioassay methods of beneficial organisms evaluation safety on pesticides had come into being. The concrete operation of this bioassay method: The collection honeybee is the best test insect. Four groups of 20~30 honeybees subjects each. Better pre-treatment method is low temperature or no-treatment. 50% cane sugar syrup or honey feed honeybee and feed toxicity. The culture utensil (d=12cm) or the gauze cage (d=9cm) serves as testing vessel. The testing filling is gauze. The temperature of recovery room must be controlled at 25 2 and the illumination keep glimmering. The mortality will be registered after 96 hours. The topical application is dropping 1.75HL pesticides on the tergum of fro-thorax or abdomen.Silkworm: 4 pesticides had done the testes time after time. These testes included silkworm stadiums, the ages in days of 2 stadium and 3 stadium, the quantity of mulberry leafages that had were dipped pesticide, how long being the leafages of mulberry dipped pesticide, whether or not feeding silkworm before the test, the quantity of pesticide in culture utensil, the temperature of recovery room, bioassay methods, spring or harvest silkworm and the bioassay methods of osculatory toxicity. All of this has remarkably affected the testing results.Though all testing data were assayed, we had the ascertained a suit of the rational bioassay methods of silkworm evaluation safety on pesticides. The operations of the bioassay method are as follows.The test insect is half-blooded silkworm; the sensitive period of silkworm on pesticide is the second age in day of the third stadium or the second age in day of the second stadium. The time of mulberry leafage ought control in 3minutes. The quantity of poisonous mulberry leafage need attain 20-30 % avoirdupois of silkworm. The temperature of the recovery room keep at25 2 . Before testing, the silkworm mustn't feed about 10-12 hours. The culture utensil (d=9cm) adds 0.8mL pesticide when drug film is done. Each group includes ten silkworms and repeats 3 groups. Other the test result must be made out what spring silkworm or harvest silkworm is used in test. The harvest silkworm is more sensitive than spring silkworm, but have some exception.Fishes: The leading fishes bioassay method evaluation safety on pesticides is half static feed in poisonous water. Tough the testing results were found that the variation of fishes, aeration status, and the temperature of water had obviously affected the LC50. The status of feeding and illumination hadn't effect for the LC50.