Boisduval scale

Diaspis boisduvalii
Recognizing Boisduval scale:

The scale cover of females of Diaspis boisduvalii is round to oval and translucent white in color with a light brown center. The scale cover of males is smaller, clear elongated and white in color with long ribbons. Often, white woolly threads are present, causing confusion with mealybugs, but this pest species does not produce honeydew. Males and females are often separated into groups on the crop. Females produce 20 to 400 eggs, usually continuous for a few weeks, until they die. Eggs are laid under the scale cover; some types are viviparous. Crawlers hatch from the eggs, move away out of the scale cover and disperse themselves on the plant for several days and seek themselves a place to settle. After the first mould they lose their legs. After the second mould in the female nymph the skin of the previous stage sticks to the existing skin and this forms the beginning of the scale cover.

Damage of Boisduval scale: 

Direct damage of Diaspis boisduvalii is caused by sucking of plant juice. Upon withdrawal of large amounts of plant juice, it inhibits the growth and development of the plant. This can, sometimes only in extreme situations, lead to leaf, flower or fruit fall, but also to death of twigs and branches and sometimes the entire plant will die. When puncturing the plant, the scales inject with their saliva toxic substances, resulting in yellow, red or brown spots on leaves and fruits. This can ultimately lead to the dying of the leaf. Armoured scales do not produce honeydew.

lifecycle Boisduval scale

  • female lays up to 200 eggs
  • eggs hatch within several days
  • development time 35-50 days
  • longevity up to 7 months

host plants Boisduval scale:

  • palms
  • orchids
  • bromeliads
  • Strelitzia
  • bananas
  • cactus


Chilocorus nigritus:

C. nigritus

Karnyothrips melaleucus:

K. melaleucus

Rhyzobius lophanthae:

R. lophanthae