Calathea Glamour Star Tiny Black Flies - Causes & Fixes

Jump to cause: Fungus Gnats (Sciaridae) Overwatering and Soil Anaerobiosis High Organic Matter Decay

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Fungus Gnats (Sciaridae)

These small flies breed in the moist organic matter of the potting soil. Their larvae feed on decaying plant material and fine root hairs, which can damage the delicate root system of your Calathea Glamour Star.

Very Common

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How to confirm: Set a yellow sticky trap near the plant or tap the side of the pot to see if tiny black flies emerge from the soil surface.

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shopping_cart Recommended Products

1 Deploy yellow sticky traps to capture the adult flying gnats and disrupt their breeding cycle.

Super Ninja Fungus Gnat Traps - 30 Pack

30 pcs

$7

In Stock

2 Allow the top inch of soil to dry out completely between waterings to kill larvae in the moist organic matter.

GROWIT Soil Moisture Meter - Blue

Water Meters

$12

In Stock

3 Apply a microbial-based soil drench to target the larvae living within the root zone.

FoxFarm Bush Doctor Microbe Brew 1 Gallon

3.8 L

$115

In Stock

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Overwatering and Soil Anaerobiosis

Calathea species require consistent moisture but are highly sensitive to stagnant water. Excessively wet soil creates an ideal breeding ground for fungus gnats and can lead to root rot.

Very Common

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How to confirm: Stick your finger two inches into the soil to check if it remains saturated long after a watering session.

build How to fix it

shopping_cart Recommended Products

1 Reduce watering frequency and allow the top inch of soil to dry out completely before watering again to disrupt the fungus gnat life cycle.

GROWIT Soil Moisture Meter SMM-V3

Water Meters

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2 Apply a biological control like Bonide Captain Jack's Neem Oil to target the larvae and adults, and use yellow sticky traps to capture flying adults.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

3 Repot the plant in a well-draining medium enriched with perlite to improve aeration and prevent soil anaerobic conditions.

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High Organic Matter Decay

If the potting mix contains too much peat or decomposing bark, it provides a nutrient-rich environment for fly larvae. The breakdown of this organic matter attracts flies looking to lay eggs.

Common

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How to confirm: Inspect the top layer of the soil for any signs of white fungal growth or visible movement within the substrate.

build How to fix it

shopping_cart Recommended Products

1 Apply a biological insecticide to eliminate the adult flies and larvae by targeting the pest lifecycle.

Bonide Captain Jack's Neem Oil 32 oz

0.9 L • 1 pcs • Organic

$10

In Stock

2 Deploy yellow sticky traps near the soil surface to capture flying adults and monitor the infestation level.

Super Ninja Fungus Gnat Traps - 30 Pack