EN
This investigation was carried out on 1-3 days old eggs, as well as on 1, 3 and 5 day old larvae. The bee brood was treated with Apiwarol AS or Fumilat in special chambers containing 1/5 of the beehive dadant. The dosage used was 5 times lower than that for normal bee families. In the control group with eggs, 91.9% bees were exterminated and approx. 83% treated with Apiwarol AS. The unfavourable effect of Apiwarol AS was confirmed on 1, 3 and 5 day old larvae. The average exterminated bees from the brood treated with Apiwarol AS was 61.6%, which was 21% lower than in the control group. On the other hand, Fumilat was not so toxic. Eggs treated with Fumilat had approx. 90% exterminated bees. The average exterminated bees from the brood treated with this drug was 84% which was 1.4% lower than in the control group. Apiwarol AS has a greater effect on the reduction of bee body weight when compared with Fumilat. Nervertheless, the 1-day old larva stage of bee life is most sensitive to anti-varroa drugs.