Appearance

• Cocoons hide under the soil.growing araucaria in soil image by joanna wnuk from Fotolia.com
  
  Fungus gnat eggs are semi-transparent, oval, shiny and barely visible. Fungus gnat larvae are threadlike, black headed, white and up to 1/8 inch long. Adult fungus gnats are 1/16 to 1/8 inch long, mosquito like, black bodied and delicate, with tiny white wings. Adult fungus gnats have a vein pattern in their wings. Small underground cocoons hold the pupae of developing fungus gnats.
  
  

Life Cycle

• Fungus gnats commonly reproduce in moist soil where there is decaying plant matter. Female fungus gnats lay up to 300 eggs. Eggs usually hatch in less than one week, and fungus gnats spend about two weeks as larvae. Compared to the adult form, fungus gnat larvae are quite large. Adult fungus gnats live for seven to 10 days.
  
  

Signs of Fungus Gnats

• Wilting is a sign of fungus gnats.dying flowers image by hoselx from Fotolia.com
  
  Fungus gnats feed off new roots and stems, especially in young plants. Common signs of fungus gnats on houseplants include yellowing leaves and sudden wilting and brown spots on the leaves and stems. In severe infestations, fungus gnats fly above the soil. Fungus gnats can easily kill young plants.
  
  

Causes of Infestation

• Nurseries spawn fungus gnats.serre 2 image by Duplic System" from Fotolia.com
  
  Several factors contribute to fungus gnat infestation in house plants. Over watering, poor drainage and excessive fertilizing of plants are the most common causes of gnat problems. Other fungus or mold in the house or garden may also harbor fungus gnats, which can spread to houseplants. Fungus gnat eggs may also be visible in various animal fertilizers and they are common in rich soil from nurseries.
  
  

Prevention and Treatment

• Soak garlic powder in water.measuring cup image by Antonio Oquias from Fotolia.com
  
  Use caution when buying soil and plants from nurseries. Do not over water houseplants. Regularly check houseplants for signs of fungus gnats. If fungus gnats have already infested the plants, create a solution of 2 cups water and 3 tbsp. garlic powder. Set the solution aside overnight before diluting it with several gallons of water. Use the diluted garlic water to saturate the soil around the plants. Yellow sticky traps are also effective for killing fungus gnats. Yellow containers of water act as inexpensive traps; the gnats are attracted by the color and drown in the water.