Insects in Greenhouse

[bookend]

Earlier today I started clearing out my unheated greenhouse for the new gardening season. During the clean-up, I moved some growbags only to find around twenty black insects leaping about into the air from the soil surface. Within a few seconds, they’d hopped off elsewhere in the greenhouse and I think some may even have got back into the soil.
I couldn’t get a close look at them in time, but they were black in colour and around 5mm in length and possibly slightly curved in shape.
I’ve heard about flea beetles, but the insects I had seem to be too large and not quite beetle shaped. Could anyone shed any light on what these insects might be please? I normally grow tomatoes and cucumbers in the greenhouse.

Many Thanks.

[Hawkwalk]

did they have wings? possibly sciarid flies.

[bookend]

No, I don't think they had wings but having looked them up on the internet since you answered, it seems that there are wingless female types of sciarid flies. From the descriptions on the web, they might well be sciarid flies. I'll try and catch some of the blighters tomorrow to have a closer look.

Many thanks Hawkwalk.

[samuelcat]

You should empty and clean your greenhouse every spring. Wash it with diluted Jeyes fluid. And wash all your pots and seed trays in diluted fluid as well. You can also get a smoke cone to fumigate it.