[Trials using drugs in diseases of the silkworm (Bombyx mori L.)]

Studied was the pharmacokinetic of chloramphenicol, tylosine, ampicillin, and penicillin in silkworm moths. The antibiotics were applied only once in the form of water solutions in concentrations of 0.062 to 1 per cent for chloramphenicol, 50 to 1500 IU/cm3 for tylosine, 0.03 to 0.5 per cent for ampicillin, and 300 to 2500 IU/cm3 for benzilpenicillin at the rate of 25 cm3/cm2 of a mulberry tree leaf. It was found that chloramphenicol in conc. 0.25 to 0.5 per cent was absorbed in the alimentary canal of the silkworm and was found in the haemolymph in bacteriostatic levels up to the 96th hour following treatment. Tylosine was also absorbed, and in concentrations of 500 to 1500 IU/cm3 was shown to maintain bacteriostatic levels in the haemolymph of the moths for a period of 24-32 hours. Ampicillin and penicillin were absorbed to a slight extent, and were eliminated from the haemolymph up to the eighth hour. It is suggested to use chloramphenicol and tylosine in the concentrations referred to for the control of the spontaneous nuclear polyhedria and flasheria in silkworm moths.