Biocontrol Millet
Combating the millet head
miner with the parasitoid
wasp Habrobracon
hebetor (Say)
Top 20
Innovations that
Benefit Smallholder
Farmers
Advantages of the technology
Recommendations
• The method is pesticide-free and
does not require any protective
measures for the local population.
• The technology must be promoted
by public extension services, projects,
NGOs, producer organisations and
the private sector.
• It strengthens animal biodiversity.
• The effectiveness of the technology
has been demonstrated in three
Sahelian countries (Burkina Faso,
Mali and Niger). A mortality rate
of over 70% is achieved among
the miner larvae 4 weeks after the
release of H. hebetor over a 15 km
radius around the villages (Payne et
al., 2011, Baoua et al., 2013).
• The release of H. hebetor increased
millet grain yield by 34% (an average
of 500 t per village) compared to the
control villages where the release
operation was not implemented
(Baoua et al., 2013).
• The release bags are made from
recyclable materials available
throughout Africa.
• H. hebetor is a native parasitoid
that has no negative impact on
human health.
• The results are immediately apparent
in the fields. The producers can
monitor the effects of the releases
and participate in the assessment
of the operation.
• It is always important to target areas
of strong head miner infestation
as a priority; the insect generally
attacks early growth millet in dune
field areas.
• Additional research is necessary
to improve the packaging and
techniques for the mass production
of H. hebetor.
Context
Description of the innovation
Pearl millet (Pennisetum glaucum (L.)
R. Br.) is one of the most important
food crops in Sahelian Africa, with
an estimated annual production of
13 million t (FAO STAT, 2012). It is grown
by more than 70% of farmers and
constitutes the staple diet. Millet is well
suited to extreme weather conditions,
although its yield is increasingly low
due to certain abiotic factors and pests.
It consists of releasing a natural
parasitoid insect of the head miner,
Habrobracon hebetor Say, in infested
millet fields. This wasp, smaller than
a mosquito, paralyses several moth
larvae so that it can lay its eggs.
The problem
Since 1974, the millet head miner
Heliocheilus albipunctella (de Joannis)
has become one of the greatest threats
to millet (Vercambre, 1978). This moth
lays its eggs on the young heads and
the larvae destroy the millet’s flowers
and grains (N’Diaye, 1984; Bhatnagar,
1984). According to Krall et al., 1995,
the miner causes production losses
estimated at between 8 and 95%, and
the problem has grown more serious
in recent years. Sahelian farmers do
not have the resources to combat this
pest, which strikes at harvest time, when
considerable effort is being expended.
Low income and the high cost of
pesticides prevent Sahelian farmers from
using chemical control. The biological
approach is a method that provides
sustainable protection for the millet crop.
Their growth cycle takes 7 days, so
that within 4 weeks there are three
or four successive generations, thus
increasing the parasitoid population
and causing significant mortality rates
among the miner larvae.
Adult H. hebetor
on a grain of millet
Millet head infested
by the miner
Moth larvae
parasitized by
H. hebetor
1. How are the release
bags prepared?
2. H
ow are the release
bags used?
You need a 10 cm x 7 cm jute bag
containing 50 g of millet flour and
30 g of millet grains, 25 Corcyra
cephalonica larvae and two mated H.
hebetor females. The bag is placed
in a sealed plastic bucket for at least
24 hours, long enough to allow the
biological control agent to paralyse
and lay eggs on the larvae of the moth
C. Cephalonica. One bag releases an
average of 60 adult parasitoids and
their emergence is scaled over
2 weeks, starting 7 days after the
system is prepared (Ba et al., 2014).
a. It is advisable to use 15 release bags per
village. They are placed in groups of
three at five points around the village.
H. hebetor release bag
b. To protect them from bad weather,
they should be attached to the roofs
of granaries or beneath plastic
buckets suspended from trees.
c. The operation can be evaluated 4 to
6 weeks after the releases. This will
determine the proportion of miner
larvae parasitised by H. hebetor and
provide an estimate of the surface
area covered by the operation.
Locations for the release bags
around the village
Installation of the release bags
under trees or in granaries
Installation of the release bags
under trees or in granaries
Husks of the miner larvae with
traces of H. hebetor cocoons
References:
Ba, N.M., Baoua, B.I., Ndiaye, M., Dabire-Binso, C.,
Sanon, A. and Tamo, M. 2013. ‘Biological control of
the millet head miner Heliocheilus albipunctella in
the Sahelian region by augmentative releases of the
parasitoid wasp Habrobracon hebetor: effectiveness
and farmers’ perceptions’. Phytoparasitica 41(5):
569–576.
Ba, N.M., Baoua, B.I., Kabore, A., Amadou, L.,
Nassirou, O., Dabire-Binso, C. and Sanon, A. 2014.
‘Augmentative on-farm delivery methods for the
parasitoid Habrobracon hebetor Say (Hymenoptera:
Braconidae) to control the millet head miner
Heliocheilus albipunctella (de Joannis) (Lepidoptera:
Noctuidae) in Burkina Faso and Niger’. BioControl,
59(6): 689–696.
Baoua, B.I., Amadou, L., Nassirou, O., Payne, W.
and Nansen, C., 2013. ‘Quantitative analysis of
augmentative biological control of the millet head
miner’. Bulletin of Entomological Research,
Bhatnagar, V.S. 1984. Rapport d’activité (novembre
82- octobre 84) Programme de lutte biologique.
Projet CILSS. Nioro du Rip, Sénégal, 78pp.
Krall, S., Youm, O. and Kogo, S.A. 1995. Panicle
Insect Pest Damage and Yield Loss in Pearl Millet. v
Nwanze, K.F. and Youm, O. (ed.) Panicle Insect Pest of
Sorghum and Millet: Proceeding of an International
Consultative Workshop 4-7 October 1993 ICRISAT
Sahelian Center, Niamey, Niger.
N’Diaye, A. 1984. Etude de la biologie et du cycle vital
de Raghuva albipunctella De Joannis (Lepidoptera
; Noctuidae) ravageur du mil pénicillaire au Niger.
Mémoire de Maîtrise. Département de sciences
biologique. Université du Québec à Montréal,
Canada. 120pp.
Payne, W., Tapsoba, H., Baoua, I.B., Malick, B.N.,
N’Diaye, M. and Dabiré-Binso, C. 2011. ‘On-farm
biological control of the pearl millet head miner:
realization of 35 years of unsteady progress in Mali,
Burkina Faso and Niger’. International Journal of
Agricultural Sustainability, 9(1): 186–193.
Vercambre, B. 1978. Raghuva spp et Massalia sp,
chenilles des chandelles du mil en zone sahélienne.
Agronomie Tropicale, 33: 62-79.
For more information:
@CTA 2016
Cover illustration: Geert Gratama
Contact: Baoua Ibrahim
University of Maradi
BP 465 Maradi, Niger
Tel: +227 9697 0190
E-mail: [email protected]
www.cta.int