Phenacoccus manihoti

Phenacoccus manihoti

Phenacoccus manihoti
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Family: Pseudococcidae
Genera: Phenacoccus
Species: P. manihoti
Binomial name
Phenacoccus manihoti
Matile-Ferrero, 1977

Phenacoccus manihoti is a scale insect species.

In the early 1970s, Phenacoccus manihoti was accidentally introduced to Africa.[1] Within 15 years of its discovery, it had invaded most of West and Central Africa and was spreading to the East.[2] It soon became an important pest, and methods to control it became a topic of interest.[1]


  • Description 1
  • Sensory structures 2
  • Damage 3
  • Control 4
  • References 5


Phenacoccus manihoti is a type of mealybug. It is commonly called the cassava mealybug because it feeds on cassava. It is an oligophagous insect that demonstrates an aphid-like phloem feeding behavior.[3] P. manihoti reproduces by thelytokous parthenogenesis[3] and goes through four in-star larval forms which have differing numbers of antennal segments.[4] Mealybugs are noted for the production of dermal wax secretions.[5] The body is covered with wax producing pores which have been well studied but the function of wax to particular species is based on speculation.[5] Predictions about the function of dermal wax in the cassava mealybug suggest it is to prevent desiccation and to deter predators.[5] The longer coils of wax secreted would be bitten first by a predator and give the cassava mealybug a chance to escape.[5] Females have the highest fecundity on the first or second day of oviposition.[6] The optimal temperature for populations of the cassava mealybug is between 20 and 30 degrees Celsius.[6] The cassava mealybug has poor survivability during rainy season because it gets washed off the plant and drowns.[6][7]

Sensory structures

The cassava mealybug has similar host plant detection behavior to

  1. ^ a b Neuenschwander, P., et al,. 1990. Biological Control of the cassava mealybug Phenacoccus Manihoti (Hom., Pseudococcidae) by Epidinocarsis lopezi (Hym., Encyrtidae) in West Africa, as influence by climate and soil. Agriculture, Ecosystems and Environment. 32: 39 – 55
  2. ^ a b Hennessey, R. D, et al,. 1990. Spread and current distribution of the cassava mealybug, Phenacoccus manihoti (Homoptera: Pseudococcidae), in Zaire. Tropical Pest Management. 36: 103 – 107.
  3. ^ a b Calatayud, P. A. 2000. Influence of linamarin and rutin on biological performances of Phenacoccus Manihoti in artificial diets. Entomologia Experimentalis et Applicata. 96: 81 – 86.
  4. ^ a b c d Le Ru, B., et al,. 1995. Antennal sensilla and their possible functions in the host-plant selection behavior of Phenacoccus manihoti (Matile-Ferrero) (Homoptera: Pseudococcidae). International Journal of Insect Morphology and Embryology. 24: 375 – 389.
  5. ^ a b c d e Cox, J. M. & Pearce M. J. 1983. Wax produced by dermal pores in three species of mealybug (Homoptera: Pseudococcidae). International Journal of Insect Morphology and Embryology. 12: 235 – 248.
  6. ^ a b c d e Lema, K. M. & Herren, H. R. 1985. The influence of constant temperature on population growth rates of the cassava mealybug, Phenacoccus manihoti. Entomologia Experimentalis et Applicata. 38: 165 – 169.
  7. ^ a b Iheagwam, E. U. & Eluwa, M. C. 1983. The effects of temperature on the immature stages of the Cassava Mealybug, Phenacoccus Manihoti Mat-Ferr. (Homoptera, Pseudococcidae). Deutsche Entomologische Zeitschrift. 30: 17 – 22.
  8. ^ a b c d Renard, S., et al,. 1997. Recognition Behavior of the Cassava Mealybug Phenacoccus Manihoti Matile-Ferrero (Homoptera: Pseudococcidae) at the Leaf Surface of Different Host Plants. Journal of Insect Behavior. 11: 429 – 450.
  9. ^ James, B. D. & Fofanah, M. 1992. Population growth patterns for Phenacoccus Manihoti Mat-Ferr on cassava in Sierra Leone. Tropical Pest Management. 38: 89 – 92.
  10. ^ a b c Le Ru, B., et al,. 1995. Ultrastructure of sensory receptors on the labium of the cassava mealybug, Phenacoccus manihoti Matile Ferrero. Entomologia Experimentalis et Applicata. 77: 31 – 36.
  11. ^ a b Atu, U. G. & Okeke, J.E,. 1981. Evaluation of insecticides for control of cassava mealybug (Phenacoccus manihoti). Tropical Pest Management. 27: 251- 253.
  12. ^ a b Chakupurakal, J., et al,. 1994. Biological Control of the Cassava Mealybug , Phenacoccus Manihoti (Homoptera: Pseudococcidae), in Zambia. Biological Control. 4: 254 – 262.


Pesticides were used as an initial response to the cassava mealybug problem. Many different kinds were used and studied and they did seem to be effective, but they were costly.[11] The most effective pesticide tested was methidathion; in trials it had a knockdown effect of 45 percent and the infested cassava showed significant recovery.[11] The use of a parasitoid E.lopezi proved to be a great success story in the biological control of the cassava mealybug. The parasitoid attacks the second and third instar stages of the cassava mealybug.[6] Within a few years of its release it covered the entire country, and within five years there were no high concentrations of the cassava mealybug present.[2][12] The successful elimination of the cassava mealybug increased farmer's cassava yields and livelihoods.[12]


The cassava mealybug can destroy up to 54% of roots and 100% of leaves in locations of infestation.[6] When it infests cassava it deteriorates the tissue mineral and nutrient contents.[5] If the plant becomes stressed during dry season it is even more susceptible to infestation.[7]