Common Disease And Pest Of Alocasia Amazonica

Alocasia Amazonica plants are beautiful lush greenery plants with large dark-green foliage that brings the beautiful scenery of the Amazon tropical forest into your home. They are often referred to as African masks and can sometimes be mistaken for the alocasia Polly.

Disease And Pest Of Alocasia Amazonica

Alocasia x Amazonica is one of the popular varieties of the alocasia specie. This is because of its very large foliage and its sharp leafy edges. It is a hybrid cross between two unverified parents from the southeastern part of Asia.

All varieties of the alocasia family all suffer from similar diseases and are often attacked by the same kind of pests. So all solutions to the problems of alocasia amazonica apply to the other varieties of the plant.

Other varieties from the Alocasia family include:

  1. Alocasia zebrina
  2. Alocasia longiloba
  3. Alocasia wentii
  4. Alocasia Reginula “Black Velvet
  5. Alocasia portei
  6. Alocasia micholitziana
  7. Alocasia cuprea
  8. Alocasia cucullata
  9. Giant Taro

Diseases That Affect Alocasia Amazonica Plants

Powdery Mildew (Phytophthora Leaf Blight)

This disease is caused by a fungus called Phytophthora colocasiae. This is a waterborne disease i.e a disease that is caused by organisms present in contaminated water used for propagation.

It Affects the leaves, stems, and blooms of the Alocasia Amazonica plants by forming a tiny patch of yellowish fluid that turns purple when dry. This disease thrives well in a warm climate and also in spaces with less air.


The signs of this disease can be recognized easily and at an early stage. The fungus usually leaves behind a trail of white powdery patches on the leaves, stems, and blooms of the alocasia Amazonica plants.


Application of organic fungicide with copper or sulfur as its primary active ingredient. Apply the fungicide weekly and switch to bi-weekly when noticeable progress is made.

Also space out the plants to ensure there is enough ventilation in the room as this fungus thrives in a heated or warm environment. 

Ensure your plant is exposed to adequate sunlight and remove infected or dead foliage carefully so as not to destroy the plant. Also, sanitize your shears to prevent spreading the disease to neighboring plants.

Crown, Stem, and Root Rot (Pythium Rot)

This disease is caused by a Pythium parasite found in contaminated water used for irrigation and watering. It is propagated through water logged in the soil. It strives in wet soil without a proper draining system.

This parasite attacks the root and stem of the alocasia Amazonica plants causing them to rot beneath the soil. If it is not diagnosed early, it can sometimes spread to the crown of the plant.


This disease is difficult to discover at the onset as a result of the fact that it occurs beneath the soil. 

At the early stage, the best way to diagnose this problem is by looking at the soil line to check for any change in soil color and sniffing out for any mushy smell.

If the parasite continues to spread undetected, the plant might stop sprouting new leaves and experience stunt growth.

Another way to check for rot in the root of the plant is by gently grabbing the stem and pulling it upwards and downwards with care. If the plant feels strong in the pot without shaking, then it’s likely not affected by the phylum parasite. But if it wiggles with ease, then it is assumed that the root is weakened as a result of rot. 


It is usually late before this disease is detected. The best way of treating this disease is by transplanting the plant to an improved soil without infections. 

Also, trim off the dead and infected foliage and only leave behind those that are still healthy.

Leaf Spot (Phyllosticta Spot)

Leaf spot disease is the least threatening among all 3 diseases discussed. It only affects the leaves of the plant by causing lesions on the surface of the leaves. The fungus is propagated through the water.

It turns the infected section of the plant foliage brown and if it’s not treated early, the most that will happen is the leaves fall off and the plant looks a little unhealthy.


Leaves develop brown patches on the leaves which spread into larger spots. If allowed to spread, the leaves die and fall off.

Also, the plant might look stunted and wilted.


Separate the infected plants from any other plant to prevent cross-contamination. 

Apply organic fungicide with sulfur and Copper octanoate. Also, ensure the water used for irrigation and watering the plants don’t touch the foliage as this disease can be transmitted through contaminated water.

Common Pests That Affect Alocasia Amazonica Plants


Leafminers refer to the larvae of various pests such as moths, beetles, fleas, etc. They appear when adult pests lay their eggs on the plant leaves which then transform into larvae. 

They are not harmful but they do leave a trail of spots on the leaves 

This can be handled by fending off other adult Pests from your plants to prevent them from laying their eggs and also using insecticidal soap when necessary to kill them off.

Spider mites

Spider mites are a common pest of alocasia amazonica. They are tiny and almost invincible to the naked eyes. They attack the leaves of the plants and leave behind a trail of spots, discoloration, and patches.

If not detected and treated at an early stage, the infected leaves will wither and fall off.

They can be controlled easily by applying insecticidal soaps on affected spots. Also, water the plant adequately as spider mites strive better in dry and dusty conditions.


Whiteflies are sap-sucking insects that cause the leaves of the alocasia Amazonica Plants to turn yellow, dry off, and then fall off.

Also, whiteflies can attract other insects such as ants to the plant as a result of the sweet substance created during the sap-sucking process.

Sticky traps can be used to trap the whiteflies and insecticidal soaps for keeping them at arm’s length.


Aphids are also sap-sucking insects that often cluster beneath leaves and release a sticky substance that can attract ants and fumagina to the plant.

Sticky traps and insecticidal soap can also be used to handle the situation.


These are usually small round brown lumps on the leaves and stem of the plant. They often appear in different shapes, sizes, and colors.

They can be handled using insecticidal soaps or by manually removing them from the body of the plant.

You can also rinse the plant in a sink to wash off all the bugs you might have missed.

Frequently Asked Questions (FAQ)

How is Alocasia fungus treated?

They can be generally treated by using an organic fungicide with sulfur or copper octanoate as the main ingredient. Also, ensure the water used for irrigation and watering the plants don’t touch the foliage as most fungus disease can be transmitted through contaminated water.

Should I cut off damaged Alocasia leaves affected by the disease?

Yes. All infected leaves should be trimmed off to prevent the spread of the disease to another part of the plant. If para venture the whole leaves are infected, then you need to carefully cut the leaves making sure to not damage the green trunk above the bulb.

How do I know if my alocasia Amazonica has spider mites?

Spider mites feed on the chlorophyll in the leaves of the plant. Chlorophyll is responsible for giving color to your plants. So, as they feed on the chlorophyll, the leaves begin to have white spots and if allowed to fester, the leaves will turn yellow, die, and fall off.

How can I make natural fungicide at home?

Add half a teaspoon of liquid soap and one teaspoon of baking soda to one gallon of water. Stir the mixture and spray over the plant.

What is the best insecticide I can use against spider mites?

One of the most popular insecticides for spider mites is Neem oil. Also, any safer brand of insect-killing soap should be able to do the job.