Cassava Green MiteA case study for Classical Biological Control

Jawwad Hassan MirzaPh.D. Scholar (ID# 435108485)Acarology LaboratoryDepartment of Plant ProtectionKing Saud University, AlRiyadh, KSA

CassavaManihot esculenta (Crantz)

• Family: Euphorbiaceae• Native to South America, Exotic to Africa (16th Centuray)• Staple food for 200 million people• Tubers and leaves consumed• Low input, easy grow, survives poor soil and

harsh environment, famine reserve crop• Among major pests = Cassava Green Mite

Cassava Green MiteMononychellus tanajoa (Bondar)

(Acari: Tetranychidae)

• Native to USA, invasive to Africa (1970) • Invaded Uganda, 1971 • Spread to 27 Countries, 1985• Reduction of 50% leaf weight, 80% tuber yield• Introduced accidently

(Nyiira, 1972; Bellotti et al. 1999; Pallangyo et al. 2004)

DAMAGE SYMPTOMS

CASSAVA REGIONS

PATHWAY FOR INVASION

Lu et al. 2012

DISTRIBUTION AND INVASION

Lu et al. 2012

DISTRIBUTION IN AFRICA

Lu et al. 2012

WHY AFRICA?

• Lack of Acarologists

• Established host on large scale

• Absence of Bio-control agents

• Lack of Co-Evolution between predator and prey

IMPORTANCE OF CASSAVA

FAOSTAT, 2012

FAOSTAT, 2012

FAOSTAT, 2012

OBJECTIVEKeeping in view the importance of Cassava plant and economic state of local farmers, the objective was:

Develop an efficient management strategy that can keep the pest population under check and

is cost effective

HISTORY OF MANAGEMENT

• Cultural control didn’t give desired results solely

• Host plant resistance was a slow process

• Acaricides caused environmental, health issues and pest resistance

• Biological Control was the best option

Classical Biological ControlCosta et al. 2012

CLASSICAL BIOLOGICAL CONTROL• International Institute of Tropical Agriculture (IITA),

1980• Introduced different bio-control agents including

fungi, insects and Mites• Phytoseiid Mites• 1984: 5.2 million Phytoseiids (7 species) from

Colombia = none adapted • 1988: 5.3 million Phytoseiids from Brazil = success– (Tryphlodromalus spp, Neoseiulus spp)

Yaninek et al. 1993

CLASSICAL BIOLOGICAL CONTROL• 5 species of Typhlodromalus = T. aripo

• Introduced in Benin, 1993

• Spread to 21 countries

• In prey absence = dispersed or stayed on plant

• Reduced pest to 90%

• Increase in yield 35% in one season

• Add up $60 million/seasonOnzo et al. 2005

OTHER BIO-AGENTS• Among the Exotic and Indigenous Bio-agents• Tryphlodromalus manihoti has high predation• Euseius fustis & T. manihoti = intraguild predation • T. aripo & T. manihoti = successful results• Neoseiulus idaeus:– 32% pest control– Survives low pest density

• Euseius fustis:– Can remain on artificial diet– Best performs when used solely

(Onzo et al. 2003)

TAKE HOME MESSAGE

• Quarantine measures should be strictly followed

• Conservation of biological control agents

• Artificial diet ensures the conservation

REFERENCES• Bellotti, A.C., Smith, L. and Lapointe, S.L., 1999. Recent advances in cassava pest management. Ann. Rev.

Entomol. 44: 343-370.• Costa, E.C., Teodoro, A.V., Re go, A.S., Maciel, A.G., and Sarmento, R.A., 2012. Population structure and

dynamics of the cassava green mite Mononychellus tanajoa (Bondar) and the predator Euseius ho (DeLeon) (Acari: Tetranychidae, Phytoseiidae). Arthropods. 1: 55-62.

• Lu, H., Ma, Q., Chen, Q., Lu, F., and Xu, X., 2012. Potential geographic distribution of the cassava green mite Mononychellus tanajoa in Hainan, China. African Journal of Agricultural Research. 7: 1206-1213.

• Nyiira, Z.M., 1972. Report on investigation of cassava mite, Mononychus tanajoa Bondar. Unpublished report. Kampala, Uganda: Kawanda Research Station.

• Onzo, A., Hanna R. and Sabelis M.W., 2005. Biological control of cassava green mites in Africa: impact of the predatory mite Typhlodromalus aripo. Entomologische Berichten. 65(1).

• Onzo, A., Hanna, R. and Sabelis, M.W., 2003. Interactions in an acarine predator guild: impact on Typhlodromalus aripo abundance and biological control of cassava green mite in Africa. Exp. Appl. Acarol. 31: 225–241.

• Pallangyo, B., Hanna R., Toko M., Gnanvossou D., Mgoo V., Otema M., Onzo A., Hountondji F., Nsami E. and Mfugale O., 2004. Biological control of cassava green mite in Tanzania. Proceedings of 9th Triennial Symposium of the International Society for Tropical Root Crops - Africa Branch (ISTRC - AB) Mombasa, Kenya.

• van Rijn, P.C.J. and Tanigoshi, L.K., 1999. Pollen as food for the predatory mites Iphiseius degenerans and Neoseiulus cucumeris (Acari: Phytoseiidae): dietary range and life history. Exp. Appl. Acarol. 23: 785–802.

• Yaninek, J.S., A. Onzo and B. Ojo, 1993. Continent wide experiences releasing neotropical phytoseiids against the exotic cassava green mite in Africa. Exp. Appl. Acaro. 16: 145-160.

THANK YOU FOR YOUR TIME

Pic: A Spider Mite (Tetranychus urticae) infestation on Marygold