Our kitchen becomes inundated with fruit flies and house flies as we have so much vegetables and fruit especially apples. But I am totally opposed to traps for wasps - so if it traps start killing wasps I shan't use them. For that reason trap is on trial in our big greenhouse. But I do think if its effective with fruit flies that may be a bonus...depending!
Eco friendly trap for blue bottles, wasps, hornets, mosquitoes, fruit flies. Very easy to assemble (20 seconds!). Half fill any commercial fizzy drink bottle with either a sugary solution or beer, wine, ripe fruit or even water with sardine depending on which type of fly you wish to attract. Pop the UFO cover on and once inside, the pests will not be able to get back out. Use in the garden to reduce biting insects or blue bottles, or to protect certain areas, an orchard from wasps and hornets for example. Made in Italy, simple and effective.