Bioecology of a major pest of Arabica coffee in Eastern Africa highlands, the African coffee white stem borer, leuconotus (Coleoptera: Cerambycidae).

Régis Babin Abdelmutalab Azrag James Gichuhi Ephantus Guandaru Coffee stem borers – Main species (1)

The yellow-headed borer - Nitakeris (Dyrphia) nigricornis Coffee stem borers – Main species (2)

The African coffee white stem borer (CWSB) – Monochamus leuconotus

Exit hole

Ring barking

Entry hole CWSB – Life cycle

Egg Larva inserted in 7 instars the bark Ring barking Wood boring

18 to 24 months

Pupa Dormant stage Pupal chamber CWSB – Rearing method

 An artificial diet was developed

 A method for egg laying (coffee sticks)

 Description of reproduction and feeding behaviors

 Life table parameters at 250C

CWSB – Ecology (Moshi, )

- 24 coffee farms along an elevation transect (1100-1600 m asl)

- Contrasted shade levels, measured with the Leaf Area Index (LAI) (lux meter)

- CWSB damage observed for two years CWSB – Relationships with elevation

No correlation between CWSB infestation and elevation

Elevation (m) CWSB – Relationship with shade

CWSB infestation rate negatively correlated with LAI (p < 0.05) CWSB – Phenology linked to rainfall pattern Wood-boring (all the year)

Ring barking Ring barking April-June Dec-Feb

Adults/eggs Adults/eggs March-April November-December CWSB – Recommendations (farmer training)

Rainy season

- Look for adults and destroy them - Look for new damage (ring barking), remove frass and kill the larva - After flowering, drench systemic insecticide (neonicotinoids = thiamethoxam, imidacloprid)

Dry season

- Look for entry holes by removing frass and crash the larva with a wire - While pruning/stumping burn infested wood

CWSB – Ongoing work at icipe (Azrag A., PhD)

Using the rearing method developed at icipe:

 Complete life table at 7 constant temperatures in incubators  Development of temperature-based development models  Simulation of life table parameters and calculation of risk indices (ILCYM)  Risk mapping in current situation and under climate change Thank you for your attention!

CIRAD, UPR Bioagresseurs P.O. Box 30677-00100, Nairobi, Cell: +254 716 561 659 E-mail: [email protected] Websites: http://agents.cirad.fr/index.php/Regis+BABIN/ http://www.cirad.fr/

International Centre of Physiology and Ecology (icipe) P.O. Box 30772-00100, Nairobi, Kenya Fax: +254 (20) 8632001/8632002 E-mail: [email protected] [email protected] Website: www.icipe.org