Flying insects are likely fungus gnats
I have been trying to grow capsicum and onions in small pots, with limited success. Recently, my plants have attracted small flying insects that rest in the pots and on the soil. What are these insects and how can I get rid of them?
Tan Ho Kim
The insects are probably fungus gnats. The adults can be a nuisance; the young appear as small, translucent worms which inhabit soil and may consume the roots of young plants, though the damage is usually minimal. Their presence indicates that your growing medium is wet and rich in organic matter.
Try letting the growing medium dry out slightly before watering again. Improve the soil drainage by adding gritty elements like fine pumice or expanded clay pellets. This will dry the mix out faster and can improve plant growth. Constant wet feet can prevent plants from developing healthy root systems and taking up nutrients.
Your capsicum plant looks leggy, so your plants may not be growing under optimal light conditions. Edible plants in an apartment setting grow best with at least six hours of direct sunlight daily. A lack of sunlight can also reduce a plant’s transpiration rate and the evaporation rate of its growing medium.
These growth conditions can discourage insect infestations. You can also try placing BTI anti-mosquito pellets (based on Bacillus thuringiensis subsp. israelensis) to kill existing larvae. Yellow sticky traps can be used to trap flying adults.