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The Most Common Pest Affecting Begonia

Mealy bugs are the most common pest affecting begonia, especially with large plants with dense foliage. Dabbing the white areas with surgical spirits or meths can remove small scale infestations.

In theory, systemic insecticides should control mealy bug and similar sucking pests but few effective chemicals are now available to amateur growers. Provado is the best but not everyone finds it totally effective. This is also the best treatment to prevent or at least limit the spread of vine weevil.

Most begonias are prone to fungus diseases of which forms of mildew are the most common. Mildew spores are abundant and control should start by keeping the plants growing vigorously and well ventilated. Plants under stress due to low temperatures, too dry or too wet conditions are more likely to succumb.

Anti-fungal sprays are often used but these need to be applied before the infection has taken hold. It is best to remove affected leaves as they will never look good. Botrytis can also affect begonias and is dealt with in the same way as mildew.
Stanley R.D. da Prato

Main Pests

  • Mealybugs
    Mealy bugs are the most common pest affecting potted begonia…
  • The black vine weevil (Otiorhynchus sulcatus)
    The black vine weevil (Otiorhynchus sulcatus) is found throughout the world …
  • Mites
    There are a number of different types of mite, some clearly visible with the naked eye…
  • Thrips
    Thrips species feed on a large variety of sources, both plant and animals…
  • Aphids
    Aphids are among the most destructive insect pests on cultivated plants…


Minor pests

Some other pests that may occasionally occur are the green looper caterpillar and sciarid flies (peat gnats). These can generally be readily controlled with the use of any good insecticide.

Main Diseases

  • Mildew
    Powdery mildew is a fungal disease that attacks a wide variety of ornamental plants…
  • Botrytis (stem rot or brown rot)
    Botrytis is a fungal disease that can attack any part of a begonia plant…



  • Foliar petal
    Foliar petal is a condition where green, leaf-like petals replace the actual dorsal or guard petal…
  • Corky scab (edema)
    This condition gives the appearance of a pale brown, cork-like scale on the plant stems…
  • Bud drop
    The dropping of buds as they form may occur if the plant is under some form of stress…


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