Cassava Mealybug

An invasive pest from South America that nearly destroyed cassava production across Africa in the 1970s-80s. After its accidental introduction to Central Africa around 1973, it spread rapidly across the cassava belt, causing 50-80% yield losses and contributing to famine. The crisis was resolved by one of the most successful biological control programs in history — the introduction of the parasitoid wasp Anagyrus lopezi from South America.

Adult females are oval, pink-bodied insects (2-3 mm) covered in white mealy wax. They form dense colonies on growing tips and leaf undersides. Males are tiny winged insects rarely seen. Nymphs (crawlers) are small, mobile, and pinkish. Heavy infestations produce conspicuous white waxy masses on shoot tips.

• 1

  White waxy masses on cassava shoot tips are unmistakable — mealybug is the only pest that produces this symptom on cassava

• 2

  Peel back the wax to find pink-bodied female mealybugs underneath

• 3

  Look for brown mummified mealybugs with a round exit hole — these have been parasitized by Anagyrus lopezi (a good sign!)

• 4

  Infestations are worst during dry season and early rains when natural enemies lag behind mealybug reproduction

• White waxy masses on shoot tips and leaf undersides

• Curled, distorted, and bunchy shoot growth (rosetting)

• Yellowing and wilting of young leaves

• Dieback of growing tips in severe infestations

• Sooty mold growing on honeydew-covered leaves

• Stunted plants with reduced root yield

Cassava Mealybug can attack 1 crop species.