Pests
 
Sciarid fly Pests main menu
  Sciaridae
 

Sciarid flies are small, black insects (3-5 mm) with slender antennae and long legs. Especially the larvae cause a lot of damage.

 

  Biology
 

Glasshouse sciarids belong to the family Sciaridae. They are small (3-5 mm) long dark flies with long, slender antennae and long legs. They are particularly seen in a warm and humid environment in the proximity of plants. That's why they can occur the whole year round in the greenhouse.

After mating, the female fly lays 50-200 eggs, which hatch in 2-3 days. The emerging larvae develop through four instars over 2-3 weeks. By that time, they are about 5 mm long, translucent white in colour with a distinctive black head. They then pupate in the compost and emerge as adult flies 3 days later.

At temperatures in excess of 24°C, breeding is continuous and the life cycle takes 3-4 weeks.

  Damage
 

The larvae do not only feed on decaying organic material such as algae and mould, but also on living material such as root and stalk tissue. They pierce into the root and/or stalk of cuttings, seedlings or young plants. As a result of this, secondary plant diseases such as Pythium, Phytophtora, Botrytis, Fusarium and Verticillium can be spread.

The general syptoms of such an attack are the wilting and the slowing down of the growth of the plants. In the worst case, this might even lead to death of these plants.

The following crops frequently suffer severe sciarid attack:

seedlings, cuttings and young plants, especially if heated under mist;
certain pot plants, e.g. ferns, Poinsettia, Azalea, Cyclamen, Kalanchoe, Exacum, Gerbera, Begonia...
some long term rockwool grown crops;

 

  Beneficials
 
Hypoaspis miles Steinernema feltiae
The predatory mite Hypoaspis miles is a specialist in eliminating the larvae of sciarid flies.
Steinernema-System provides the perfect biological solution to the problem of glasshouse sciarids.
 
Atheta coriaria  
The predatory beetle Atheta coriaria is an extremely voracious and efficient beneficial against sciarid flies.
   
 

 

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