THE Substrate Gnat
This insect is not devastating but it is always good practice to know how to control it and be able to defend yourself. It occurs in indoor cultivation and you need to be careful especially in hydroponics because it loves humidity and water.
How to recognize the substrate midge?
The Substrate Gnat, scientific name Sciridae, has many common names: Black Gnat, Soil Gnat or Mushroom Gnat. The substrate midge in the larvae stage has a size of approximately 4mm, a black head and a translucent colour. As the adult grows, it develops black and gray wings, measuring from 2 to 4 millimeters and having thin, long legs.
The Life Cycle:
After heterosexual fertilization, the substrate midge lays a couple of hundred eggs in the soil, the eggs hatch after 3 days and give birth to the larva which feeds in the soil. After about 20 days the larvae form the cocoon and following metamorphosis they transform into winged insects. You will be able to spot them in the lowest part of the plant near the substrate, they feed on fungi and decaying material.
How to Spot the Substrate Gnat?
Being a lover of humid environments you will easily find the substrate midge in the lower part of the plant in the "wet" area.
What damage does the substrate midge cause?
In the larva stage this parasite feeds on the capillary roots, damaging the main ones, this leads to a decrease in the vigor of the plants and a slowing down of the metabolism. It should be added that due to damage to the roots they are subject to attack by fungi such as Fusarium, especially in the presence of very humid or wet substrates. In general, the midge does not cause much damage to large plants but is dangerous for young plants.
However, it is better not to take this insect lightly even though it is less harmful than others, because letting a parasite propagate can never bring any benefit.
How to Identify the Substrate Gnat?
- If you use sticky traps, you will notice it immediately because it will get trapped when it flies.
- You may notice them flying around the plants.
- At an advanced infestation you will notice reduced plant vigor and pale leaves.
- You may find some midges attached to shoots, as well as in sticky traps.
- Fungal infections in the roots may occur.
How to prevent substrate midge?
- Do not give too much water so that there is no stagnation.
- Check the humidity parameters and keep them correct (from 40 to 55%)
- It forms a superficial layer of vermiculite which makes it difficult to lay eggs.
- Insert chromotropic sticky traps (brightly colored yellow and blue)
- Spray Neem Oil on the substrate as well.
How to intervene in case of infestation?
- Use Neem Flour by spreading an even layer after watering.
- Insert predatory antagonistic insects such as Hypoaspis geolalepumites