除虫菊的花、茎、叶都含有杀虫有效成份—除虫菊素,但以花含量为高。不同时期采收的花,药效含量也不同,试验证明,在舌状花全开展,管状花外围开展时药力最高。开展程度是以管状花的开展情况作为标准的,一般以开展七、八成为最适中,药效既高,鲜花晒干花的折合率也较高。现将 Pyrethrum flowers, stems and leaves contain insecticidal active ingredient - pyrethrin, but the flower is high. Flowers collected in different periods, different levels of efficacy, tests show that the full development of the tongue flower, tubular flowers when the peripheral development of the highest drug. The level of development is based on the development of tubular flowers as a standard, generally to carry out seven or eight into the most moderate, efficacy is high, flowers, flowers, the higher the discount rate. Now