The potential of some insect growth regulators in housefly (Musca domestica) control

that reached 0.6–2% in the susceptible strain SRS/WHO and 1.1–1% in the wild population of housefly REKe. Field experiments included the testing of preparations Dimilin 25 WP (a.i. diflubenzuron) and Neporex 2 SG (a.i. cyromazine) and their effect on the abundance of flies over 10 weeks. The first marked decrease (by 70–87%) in the number of flies in animal houses was observed 4–5 weeks after treatment with diflubenzuron. Cyromazine caused marked reduction (74–81%) in fly populations in weeks 5–6. Up to the 10th week of the experiment, flies were reduced by 71–82% with diflubenzuron and by 65–83% with cyromazin when compared with flies in the control houses. Methoprene affected most of the 3 rd instar larvae ensuring 100% mortality in the susceptible strain SRS/WHO and 99.5% mortality in the wild population of housefly. The most pronounced effect of pyriproxyfen was recorded after its topical application to white pupae. Their mortality reached 87.2% on average in the susceptible strain SRS/WHO and 84.3% in the wild population of housefly REKe. In field conditions the most pronounced reduction in flies was observed in weeks 4 to 6. The number of flies was reduced by 45–61%. In the remaining weeks, only low reduction of flies (by 5–41%) was found after treatment by pyriproxyfen.