夏季时节植物生长旺盛，病虫害也处于高发期，本期园艺热钱，园艺高手张崇炎要介绍一种安全环保的常见除虫剂——除虫菊 ...

In ancient Persia (current-day Iran), the natural insecticide Pyrethrum, made from dried Chrysanthemum flowers, was utilized ...

DDT, the “wonder insecticide” that had millions of dollars ... They should contain both DDT and pyrethrum (or some similar toxicant). The pyrethrum knocks flies and mosquitoes down quickly.