There was a significant increase of MHM parasitization rate after the releases, with up to 97% mortality. The survey on farmers’ perceptions revealed a fair knowledge of the MHM and the ability of farmers to describe the pest and the damage it caused. Farmers claimed that the biocontrol agent H. hebetor is effective and perceived a significant gain in grain yield due to this control strategy. Implications of these findings for a large extension of the MHM biocontrol program are discussed.

1. IPM
for
Pearl
Millet
in
the
Sahel:
Augmenta5ve
on-­‐farm
releases
of
parasitoids
to
control
the
millet
head
miner
in
the
Sahel.
Malick
Ba
ICRISAT
Niger

2. Pearl
millet,
Pennisetum
glaucum
(L.)
R.
Br.,
is
the
staple
crop
of
the
dry
regions
of
Africa.
Pearl
millet
3/26/15, 2:17 AM

3. The
millet
head
miner,
Heliocheilus
albipunctella
(de
Joannis)
(Noctuidae),

4. The
millet
head
miner
damage
Ø Damage
to
the
crop
is
due
to
larvae
that
feed
on
the
panicle
and
prevent
grain
formaFon.
Ø As
the
larvae
chew
between
the
rachis
and
flowers,
they
liJ
the
destroyed
flowers
or
developing
grains,
leaving
a
characterisFc
spiral
paKern
on
the
millet
head.

5. Ø Typical
yield
losses
range
from
40
to
85%
Ø Almost
every
year
outbreaks
of
the
MHM
are
observed
in
the
Sahel
especially
on
early-­‐planted
millet
or
early
maturing
material
The
millet
head
miner
damage

6. Management
op5ons
• Control
with
insecFcides
is
not
realisFc
for
subsistence
farmers
because
of
prohibiFve
cost
and
risk
to
health
and
the
environment.
• Cultural
management
has
limited
applicability
• Host
Plant
Resistance
is
sFll
under
invesFgaFon
• EffecFve
biocontrol
agents
are
available

7. Biological
control
• The
braconidae
parasitoid
wasp
Habrobracon
(=Bracon)
hebetor
Say
naturally
inflicted
significant
mortality
to
MHM.
• But
parasiFsm
occurs
late
in
the
season
when
most
of
the
panicle
are
damaged
H.
Hebetor
developing
on
larvae
of
the
MHM

8. Augmenta5ve
biological
control
• Colony
of
H.
hebetor
are
established
and
maintained
in
the
laboratory
on
an
alternate
host,
the
rice
moth
Corcyra
cephalonica
• C.
cephalonica
is
reared
on
a
mixture
of
millet
flour
and
millet
grains
• The
parasitoids
are
released
in
15
cm
×
25
cm
jute
bags
(+200
g
of
millet
grains
+
100
g
of
millet
flour
+
25
larvae
of
the
rice
moth
Corcyra
cephalonica
(Stainton)
+
two
mated
H.
hebetor
females)
• The
jute
bags
are
suspended
to
the
ceiling
of
tradiFonal
straw
granaries

9. How
augmenta5ve
releases
are
made?
§ Parasitoid
offspring’s
escaped
through
the
jute
meshes
and
straw
granaries
and
dispersed
to
millet
fields
• A
set
of
15
bags
are
used
to
cover
5km2
area
• Roughly
an
iniFal
number
of
1000
parasitoids
are
released

10. 0
5
10
15
20
25
30
6
7
8
9
10
11
12
13
14
Number
of
parasitoids
emerging
from
the
jute
bags
Days
aKer
confinement
Daily H. hebetor adults emerging from the jute bags
Total:
70
parasitoids
Emerging
5me:
8
days

11. Effec5veness
in
controlling
the
head
miner
0
20
40
60
80
100
120
Burkina
Faso
Mali
Niger
%
parasi5zed
larvae
H.
hebetor
releases
villages
Control
(no
releases)
0
20
40
60
80
100
120
Burkina
Faso
Mali
Niger
%
parasi5zed
larvae
H.
hebetor
releases
villages
Control
(no
releases)
2007
2008

12. Challenges
• Place
of
deployment
of
jute
bag
for
communiFes
where
granaries
are
made
of
clay,
which
could
not
enable
parasitoids
to
escape?
• The
quanFty
of
millet
flour/grain
needed
for
formulaFng
the
parasitoid
bags?
• Thus,
we
invesFgated:
– effects
of
placing
jute
bags
directly
within
millet
fields
on
the
parasiFsm
of
MHM.
– Reducing
the
seize
of
the
jute
bag

13. Reduc5on
of
bags
size
by
80%
0
4
8
12
16
20
1 2 3 4 5 6 7 8 9 10111213141516171819202122232425
NumberofemergingH.hebetorper
bag
Number of days after confinement within jute bags
15 cmx25cm bags
7 cmx10cm bags
T=57
T=70
Ba
et
al.,
2014
Biocontrol

14. Ba
et
al.,
2014
Biocontrol
Type
of
bag
Number
parasitoids
emerged
(Mean
±
SE)
%
Parasi5sm
C.
cephalonica
(Mean
±
SE)
H.
Hebetor
development
5me
(Mean
±
SE)
25
x
15
cm
57.10
±
5.01
80.77
±
0.17
12.15
±
0.34
10
x
7
cm
69.80
±
5.57
87.19
±
0.08
11.64
±
0.31
T=
-­‐1.69
DF=
38
P=
0.10
T=
-­‐1.72
DF=
38
P=
0.09
T=
-­‐1.08
DF=118
P=0.27
Reduc5on
of
bags
size
by
80%

15. A
B
C
a
b
c
0
10
20
30
40
50
60
70
80
90
100
7x10cm jute bags 15x25cm jute bags Control (no parasitoid
released)
%MHMlarvaeparasitized
byH.hebetor
Burkina Faso
Niger
Ba
et
al.,
2014
Biocontrol
Reduc5on
of
bags
size
by
80%

16. Displaying
bags
within
millet
fields
A
A
B
B
0
10
20
30
40
50
60
70
80
90
100
2011
2012
%
MHM
larvae
parasi5zed
by
H.
hebetor
Years
Parasitoid
bags
directly
placed
within
millet
crop
Control
(no
parasitoid
released)
Ba
et
al.,
2014
Biocontrol

17. Completely
damaged
panicles
Saved
panicles
Economic
advantages
Up
to
30%
grain
yield
gain
Baoua
et
al,
2013.
J.
Appl
Ento

18. Way
Forward
• Establish
parasitoid
coKage
industry
•
Use
of
egg
parasitoids
for
enhancement
of
the
biocontrol
program
• Use
of
pearl
millet
tolerant
varieFes

19. Thank you!