Sciarid flies

[johnstephen29]

Hi I have a scadoxus which is infested with sciatic flies, is there any way to get rid od these? I have payed off with the watering to try and dry out the compost,I'm not sure what else to do.

[Maggi Young]

Are there signs of damage from the grubs to the plant, John?   Drying out the compost  may help a bit - but it's not  a complete answer I don't think.

 Have a look at what the RHS says about  these flies (fungus gnats)  https://www.rhs.org.uk/advice/profile?pid=804

[johnstephen29]

Hi Maggi thanks for the link, there was some useful information on there. I'm not sure if there is any damage to the plant, I'll have to tip it out and clear away the compost and check the bulb.

[Margaret]

I read that Cape sundew (Drosera capensis) was useful for controlling fungus gnat. It did seem to work for a bit but the sundew soon started to fail. Lack of sun and Thames water were likely to be the cause.

[David Nicholson]

John, is your Scadoxus in a peat-based compost? They particularly like a very damp environment and if this includes a peaty compost they thrive. Any good insecticide should sort them out, try spraying them fortnightly for a couple of months.

[johnstephen29]

Hi David it's in leaving tons John innes which is supposed to be soil based, I try to avoid peat if I can help it. I have an insecticide, but will it kill any grubs in the soil chewing on the roots?
Hi Margaret it the water hard down your way? Here the water is really hard and you have to make sure the kettle washing machine etc is kept lime scale free.

[David Nicholson]

John might be best to drench the soil rather than spray.

[Maggi Young]

No John, up here in Scotland all our water is soft -  ours is very good - very soft - no need for descaling kettles or washing machines for us.

[johnstephen29]

Your lucky Maggi if you forget the kettle in a few days the inside is soon covered and your chewing on lime scale with you tea