Bioecology of a major pest of Arabica coffee in Eastern Africa highlands, the African coffee white stem borer, Monochamus 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, Tanzania)
- 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, Kenya 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 Insect 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