1. The effects of shade, altitude and
landscape composition on coffee
pests in East Africa
Mattias Jonsson
Dept. of Ecology/ Centre for Biological Control
Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
Coauthors: Ijala Anthony Raphael, Nina Backlund, Louise Malmberg,
Jeninah Karungi-Tumutegyereize, Samuel Kyamanywa, Barbara Ekbom
World Congress of Agroforestry, New Delhi, 2013-02-12

2. Acknowledgements
Louise Malmberg & Nina Backlund
Ijala Anthony Raphael

3. How can we expect agroforestry practices to
influence pests?
+
Agroforestry plantations are more complex than monocultures
reduced pest abundances (Root et al. 1973; Teodoro et al 2009; Karp et al.
2013).
-
Agroforestry plantations may provide alternative habitat and a favorable
envirionment
increased pest abundances (Girma 2000).
+/-
The impact of agroforestry may depend on ecological context (Tscharntke et
al. 2012).

4. Study 1
Effect of shade at different altitudes
in eastern Uganda
X
Mt Elgon
Altitude (2 levels)
Shade (3 levels)

5. Shady plantations had highest infestation of
stemborers, especially at low altitudes
White stem borer
(Monochamus leuconotus)
Local shade: **
Prop tree cover: NS
Local shade X prop tree cover : *

6. Shady plantations had lowest infestations of
coffee berry borer
Coffee berry borer
(Hypothenemus hampei)
Local shade: *
Prop tree cover: NS
Local shade X prop tree cover : NS

7. Study 2
Effect of shade in landscapes with different cover
of trees in western Kenya
X
Tree cover in landscape
(gradient)
Shade (2 levels)

8. The effect of local shade level depended on
landscape composition
Lacebugs
Habrochila spp.
Local shade: **
Prop tree cover: NS
Local shade X prop tree cover : ‫٭‬

9. Summary:
Are shade-trees useful for pest control in coffee?
White stemborer
NO – especially not at lower altitudes!
Coffee berry borer
Which pest is
most
important?
YES!
Doesn’t
matter
Lacebugs
What does the
landscape look
like?
NO!

10. Poster: Agroforestry to improve soil
health and pest management
in the humid-tropics: a meta-analysis
Positive
8
Negative
No effect
7
Number of data points
7
6
5
5
4
4
3
2
2
2
1
1
0
Reduction of pest abundance
Reduction of plant damage
Very few studies have tested the effect on pest control!