Studies On The Relationship Between The Symptoms And Mechanism Of Different Kinds Of Insecticides

The poisoning symptoms and mechanism of insecticides are the main content of Insecticides Toxicology. They have been studied deeply and systematically. But the research was mostly independent to each other, and it can be seen in three aspects: (1) the describe to the poisoning symptoms of insecticide are rough and unsystematical; (2) simple and accurate indexes are scarce in detecting and judging the mechanism of all kinds of insecticides; (3) the expounding to the relationship between the poisoning symptom and mechanism of insecticides are somewhat obscure. The relationship between the poisoning symptoms and mechanism of insecticides are practically the relationship between phenomenon and essence. Expounding this relationship systematically, especially the relationship between poisoning symptoms and some simple biochemical or physiologic indexes in insects, can fulfill the content- of Pesticide Toxicology, and provide some theoretic references to the development of new insecticides. At the same time, in the research of the mechanism of new insecticidal compounds, it will provide useful clues to judge rapidly the main poisoning mechanism.Based on above, the poisoned symptoms were described in larval of Mythmina separata Walker, adults of Musca domestica, and apterous adults of Aphis gossypill G., which were treated with typical insecticides of 13 kinds of insecticide ,including DDT, organophosphorus insecticide etc.. Certain biochemical or physiologic indexes of larva of armyworm were tested to verify the mechanism of some of these insecticides. Based on the relationship between the insecticide varieties, poisoning symptoms and toxicity mechanism, a key about them was established. Some conclusions have been obtained by above research.1. The result of observing symptom suggested that all kind of insecticides assuming respectively typical poisoning symptoms. (1) Both DDT and hexachlorocyclopentadienesinsecticides caused insects exciting, convulsing, paralysis and dead. The distinguish of them lied in the less excitation induced by hexachlorocyclopentadienes than by DDT, and the body of larva of army worm died of hexachlorocyclopentadienes was very shrunken and shortened, the length of the body was almost a half of the check. (2) The typical poisoning symptoms induced by the pyrethroids insecticides were characterized by strongly excitation or direct convulsion, paralysis and dead, and the poisoned insects lost water heavyly in cuticle. (3) Both organophosphorus insecticides and carbamates insecticides could cause insect exciting, convulsing, fainting (prostration) and dead. The difference between the two kinds of insecticides lied in that the active speed of carbamates was more quickly. The insect immediatly came into excitation phase after treated by Cars and the excitation was more strongly than by Ops. Tested insects had a post-treated still period before exciting, by treated with organophosphorus insecticides. (4) To nicotine insecticides, at a low lethal dosage (eg the doseLD7o), the tested insects were directly induced to be in convulsion , and at once in prostration. (5) Both nereistoxins insecticides and Avermectin directly caused tested insects paralysis and dead, the difference was that a part of the paralysis insects could recover by treated with nereistoxins. (6) It seems that the symptom was closely correlative with the dosage for formamidine insecticides. Tested insects represented vari-abnormal behaviour after treated with sub-leathal dosage, but they gradually dead after extitation, convulsion and faint at leathal dosage of formamidines. (7) The poisoning symptoms of fiprohil to insects were the same as that of both organophosphorus insecticides and carbamates insecticides, thay all could cause insect exciting, convulsive, faint (prostrate) and dead;(8) The poisoning symptom of rotenone could be divided into three stages, weakly...