harnessing biodiversity for sustainable pest management

International Institute of Tropical Agriculture – Institut international d‟agriculture tropicale – www.iita.org

Harnessing biodiversity

for sustainable pest management

Manuele Tamò

insect ecologist

Contract Review Seminar, October 13, 2009


Cowpea, Vigna unguiculata Walpers

Major source of proteins

for balanced diet with

starchy staples

Dual purpose: food-feed

But: substantial losses due

to pests and diseases


Strategic vision for cowpea IPM (5-10 years)

Preventive side:

• Host plant resistance (incl. transgenics)

• Conservation biological control

Curative side:

• Inoculative and augmentative biological control

• Bio-pesticides

• Synthetic insecticides


The legume pod borer, Maruca vitrata


Ecology studies

Major alternative host plants in moist savannas of West Africa

Pterocarpus santalinoides Lonchocarpus cyanescens Lonchocarpus sericeus

Tephrosia candida


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P. santalinoides

L. sericeus

T. platycarpa

Abundance of larvae of M. vitrata on selected host plants in Southern Benin


Pheromone traps as monitoring tools

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Within Flowers

Within Pods

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Females

Males


Population „migration‟ of M. vitrata based on available

data from light traps and host plant surveys: implication

for control strategies


Biodiversity studies

Natural enemies of Maruca vitrata in West Africa

Egg parasitoids

Trichogrammatoidea eldanae

1 mm


Natural enemies of Maruca vitrata in West Africa

Braunsia kriegeri

Phanerotoma leucobasis


Maruca vitrata larval parasitism rates on different host plants in Benin

Phanerotoma leucobasis

Braunsia kriegeri

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Lc Ls Ps Pp Tp Vu

Lc: Lonchocarpus cyanescens

Ls: Lonchocarpus sericeus

Ps: Pterocarpus santalinoides

Pp: Pueraria phaseoloides

Tp: Tephrosia plathycarpa

Vu: Vigna unguiculata (cowpea)


Source: CABI Crop Protection Compendium

What‟s the origin of M. vitrata and why do we bother?


Apanteles taragamae Dolichogenidea sp.

Triclistus sp. Trichomma sp.

Biodiversity studies at AVRDC, Taiwan


Apanteles taragamae Viereck (Hymenoptera, Braconidae)

Biological and ecological studies

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Experimental releases

…but no direct evidence

of establishment yet


Biodiversity of

entomopathogenic

organisms

Several fungal pathogens

identified, none of practical

interest

Incidence of infection of M.

vitrata cypovirus (MvCPV) from

<10% to 100% (6% severely

infected)


A serial killer: Maruca vitrata Nuclear

Polyhedrosis Virus (MaviMNPV)


MaviNPV: lab studies at AVRDC

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Days after treatment

Mo

rtality

(%

)

Check 100 PIBs/ml 500 PIBs/ml 1000 PIBs/ml 2500 PIBs/ml 5000 PIBs/ml

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a a aa

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aa a a a

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100%

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days after application

mo

rta

lity

Control

2.053x10º

2.053x10¹

2.053x10²

2.053x10³

2.053x104

2.053x10 5̂

MaviNPV: lab studies at IITA with Benin

populations of M. vitrata


MaviNPV: caged field studies at IITA-Benin

treatement

(OB/ha)

% mortality

0.1000 9,12 c

2.1009 24,43 bc

2.1010 35,55 bc

2.1011 56,25 ab

2.1012 75,00 a

2.1013 87,92 a


+ = !!!!!

A. taragamae and MaviMNPV flying together !


TreatmentstrExposure time

2 h 24 h

Control 0 b 0 b

Ovipositor 0,91 a 0,96 a

Whole body 0,94 a 0,97 a

Diet 0,90 a 0,98 a

P>F <0,0001*** <0,0001***

Presence of MaviMNPV OB in larvae of Maruca vitrata as a

function of different contamination methods using 2h and 24h virus

exposure time.

Another important discovery: at temperatures <25 C co-infected

larvae will be killed by the virus before parasitoids can form a cocoon


Strategy for deploying biocontrol agents:

Exotic parasitoids:

• overall reduction of the population pressure,

particularly on wild host plants during the off-

season

MvNPV:

• to be used like a biopesticide for inundative

biological control e.g. once pheromone derived

threshold is reached


Insect resistant cowpea – conventional breeding

2 spray No spray

Variety Grain

(kg/ha)

Fodder (kg/ha)

Grain (kg/ha)

Fodder (kg/ha)

IT90K-277-2 2697 2219 549 3236

IT95K-231-1 2235 2619 312 3043

IT95K-193-12 2020 1513 496 1462

Dan lla (Local) 1407 3050 14 3677

• no reliable sources of resistance in crossable species

• wide crosses unsuccessful

• use of susceptible varieties possible with chemical control


Table 2 Performance of cowpea Breeding Lines in Ibadan During the Second Season

(September to November) of 1998

______________________________________________________ Spray No Spray _______________________ Cowpea Line Total seed Good seed Total seed Good seed IPE* yield (kg/ha) yield (kg/ha) yield (kg/ha) yield (kg/ha)

___________________________________________________________

IT95M-268-1-4 1530.7 1377.4 1479.5 1350.8 25.0

IT95M-305-1 1479.5 1313.6 1328.6 1190.2 26.5

IT95M-190-4 1539.1 1348.2 1303.2 1123.6 26.8

IT95M-7 1567.0 1520.7 1256.1 1192.7 35.5

IT95M-190-1 1349.0 1233.6 1192.7 980.2 26.8

IT95M-309-1 1490.3 1450.3 1177.3 1091.5 23.0

IT95M-249-1 1502.8 1425.7 1127.7 935.6 27.5

TVU14476 (CK) 1207.3 1120.2 994.8 915.6 30.0

IT86D-715 (CK) 1034.4 876.8 673.1 574.3 20.0

IT86D-719 (CK) 1012.3 821.4 614.3 457.6 22.5

LSD 5% 310.4 303.3 380.8 355.2 6.8

CV % 16.1 17.1 24.1 25.1 17.7

__________________________________________________________

*IPE = Pod evaluation index


1 2 3 4 5 6 7 8 9

75 Kd

50 Kd

37 Kd

Pet YL OL SEP PET Poll Pod Imm Mat

Seed Seed

The Bt-protein is found in most green

organs of transgenic cowpea

Cry 1Ab*

*LSUCourtesy: T.J. Higgins, CSIRO


Bt-mediated effect on M. vitrata parasitoids

- using different doses of Cry1Ab

toxin on Phanerotoma leucobasis

- Parasitoid egg inserted in M.

vitrata egg, but development of

parasitoid larva only in late 1-st

instar

- substantial mortality of developing

parasitoids only when exposed to

LD95


Other parasitoids to be studied:

-Trichogrammatoidea eldanae (egg, local)

- Braunsia kriegeri (larva, local)

- Pristomerus sp. (larva, local)

- Bracon sp. (larva, local)

- Dolichogenidea sp. (larva, local)

- Testudobracon sp. (larva, local)

- Apanteles taragamae (larva, exotic)

- Bassus aper (larva, exotic)

- Nemorilla maculosa (larva, exotic)

Prospective NTO studies on M. vitrata natural enemies


Other Leps encountered on cowpea:Arctiidae

Amsacta sp.

Gracillaridae

Acrocercops sp.

Lycanidae

Euchrisops malathana

Virachola antalus

Lymantriidae

Euproctis innonata

Noctuidae

Agrotis ipsilon

Helicoverpa armigera

Spodoptera littoralis

Trichoplusia limbirena

Olethreuthidae

Cydia ptychora

Pyralidae

Elasmopalpus lignosellus

Etiella zinckenella

Sylepta derogata

Prospective NTO studies on other Lepidoptera


MR-cowpea Biopesticides as

tools in IRM

„IPM model‟ for Maruca vitrata

Alternative host

plans (BC and IRM)

Novel BC agents


Looking ahead:

Another potential biocontrol candidate from Taiwan:

Nemorilla maculosa (Diptera, Tachinidae)


A parasitoid which also attacks a recalcitrant polyphagous pest:

Helicoverpa armigera


New BMZ project: large biodiversity of M. vitrata

natural enemies in Asia and maybe in South America


Pulses-CRSP project: M. vitrata rearing for national

programs and farmer groups


What is this mess???


Rearing methodology with germinating cowpea grains is 25-30x less

expensive than standard artificial diet for the same larval output level !!!


The bean flower thrips, Megalurothrips sjostedti Trybom (Thys., Thripidae)

Photo: G. Goergen


Biodiversity studies: natural enemies of M. sjostedti

Larval parasitoid: Ceranisus menes Walker

Predator: Orius albidipennis Reuter

0.5 mm

Egg parasitoid: Megaphragma sp.


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%

V. unguiculata

P. santalinoides

L. sericeus

L. cyanescens

T. candida

Parasitism rates of M. sjostedti larvae by C. menes on

selected host plants

31754

7590

8357

5671

8222


Origin and distribution

Megalurothrips sjostedti

Megalurothrips usitatus


Discovery of the thrips parasitoid Ceranisus femoratus in

Cameroon

V. unguiculata

C. pubescens

D. guineensis

T. candida

5841

130

2315

1110

Important parasitism rates on wild host plants


Dioclea guineensis


Laboratory rearing very labour intensive and expensive

2 mm


In-field mass rearing on Tephrosia candida


Megalurothrips sjostedti

Establishment of the exotic thrips parasitoid Ceranisus

femoratus 3 years after the initial releases in three

countries


Large dataset from Benin,

comparing multi-year data

before releases and 4 years

data after the releases

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250

Lonchocarpus

sericeus

Lonchocarpus

cyanescens

Pterocarpus

santalinoides

Tephrosia

bracteolata

Tephrosia

candida

Average number of M. sjostedti larvae per inflorescence of

different host plant (blue: period 1992-95, red: period

2005-2007)


Ecological impact: up to 43% reduction of thrips population

on wild host plants

Economic impact: on-going collaboration with agro-

economists for developing ex-ante impact assessment

models


Cultivars Damage index

First season Second season

Moussa local 2.06 c 3.42 cd

Sewe 2.06 c 3.42 bc

Sanzisabinli 2.13 c 1.93 d

TVu 1509 (RC) 2.38 c 3.25 cd

IT90K-277-2 4.88 b 3.67 cd

KVx404-8-1 4.88 b 4.67 b

IT91K-180 5.06 b 5.75 a

TVx 3236 5.13 b 5.17 b

Vita7 (SC) 7.56 a 7.59a

Host plant resistance


Complementary biocontrol agents targeting the cowpea

plant: the predatory mite Amblysieus swirskii


IPM approach for flower thrips

- Host plant resistance in available germplasm

- Improved biological control:

On wild hosts: Ceranisus femoratus

On cowpea: Amblyseius swirskii

- Biopesticides:

entomopathogens

botanical extracts


Cowpea aphid, Aphis craccivora


Aphid colonies

destroyed by

Neozygites fresenii

in the Oueme valley

(Benin) during

„harmattan‟

conditions


Cowpea aphid Aphis craccivora

Zone aphid infection infestation rate

South <10 96% Center >200 7% North >500 0%

Impact of the entomopathogenic fungus Neozygites fresenii


Natural enemies

biodiversity studies:

• „usual‟ predator

complex

• but no hymenopteran

parasitoids until mid-

2007


Possible new biocontrol

project?

Source: CABI Crop Protection Compendium


Mumies of the parasitoid Lysiphlebus testaceipes


On-going and futures studies:

• Interactions with entomopathogenic fungus

Neozygites fresenii

• Interactions with alternative host plants for the

cowpea aphid

• Interactions with other aphid species (e.g. Aphis

gossypii)

• novel natural enemies from Mid East


Potential for using bio-pesticides against pod

sucking bugs

Clavigralla tomentosicollis killed by

the fungus Beauveria bassiana

Investigation of aggregation

pheromones for developing “lure and

kill” approaches


PRONAF: Farmer participatory

approach for IPM

Farmer Field School model has been

modified and adapted to local conditions

within the cowpea agroecosystems in

Africa

- combined ToT/FFS within the same

season (saves one season)

- no need for validation trials for

technologies already developed on-farm

by the various national programs (saves

another season)

- ToT at country level is non-residential

(cost savings)


New technology for FFF?

Solar-powered MP3 players

- FFF can now be augmented

with messages regarding the

agricultural issues being

addressed.

- Such devices can be taken

back to the communities

where the messages can be

played repeatedly (biggest

advantage over rural radio

messages which are often

played only once)


Biological control of the millet head borer

Heilochaelus albipunctella (McKnight foundation)

Millet head borer damage

Parasitoid: Habrobracon hebetor


Nord

NIGERMALI

BURKINA

FASO

ZinderNiamey

Ouagadougou

Bamako

Sego

u

Villes

Maradi

Zone de lâcher

du parasitoïde

Parasitoid release areas


Country Villages Producers keeping release bags Release bags

installed

Evaluation

(villages assessed)

Number of millet

spikes observed

Men Women Release villages Control villages

Niger 90 470 25 1303 24 8 14400

Burkina Faso 51 235 20 690 23 5 16350

Mali 31 83 10 465 31 8 17750

Total 172 788 55 2458 78 21 48500

Full farmer-participatory biological control project


Burkina, 2008

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Seytenga Gorgadji Dori Arbinda Seytenga Gorgadji Dori Arbinda

Villages lâchers villages témoins

Larvae killed by H. hebetor

Larvae killed by others


Prototype mass production of

trichogrammatids against millet

head borer

Trichogrammatoidea eldanae


Developing alternatives to cotton pesticides in

Benin (Dutch Embassy in Benin)

Cotton bollworm, Helicoverpa armigera


- biopesticides:

entomopathogens, neem oil

- trap plants: sunflowers,

marigolds

- conservation of locally

available natural enemies

(parasitoids, spiders etc.)

- integration of all these

options


Milieux paysans (Banikoara)

Godou

Ounet

Goumonri

Founougo

Pratiques

Nombre moyen de H.

armigera par

cotonnier

Rendements moyen (kg/ha)

Nombre moyen de H.

armigera par

cotonnier


Nombre moyen de H.

armigera par

cotonnier


Nombre moyen de H.

armigera par

cotonnier

Rendements moyen

(kg/ha)

Huile de neem 0,090 ± 0,031 a 990 ± 248 a 0,056 ± 0,033 a 460,4 ± 99 0,967 ± 0,160 a

333 - 410,4 ± 69

Metarhizium

anisopliae

0,124 ± 0,034 a 1238 ± 35 a 0,061 ± 0,035 a 212,5 ± 6 1,000 ± 0,180 a 238 - 218,8 ± 38

Beauveria

bassiana

0,071 ± 0,051 a 998 ± 43 a 0,045 ± 0,028 a 495,8 ± 84 1,096 ± 0,191 a 340 - 379 ± 65

Conventionnel 0,200 ± 0,108 a 1154,2 ± 211 a 0,085 ± 0,037 a 517 ± 214 1,033 ± 0,165 a 538 - 556 ± 232


IPM of cashew pests (BMZ)

The (invasive?) cashew leafminer Eteoryctis syngramma (Meyrick)


New challenges in insect ecology

Apate terebrans in action


At IITA

C. Agboton, B. Datinon, D. Djegui, D. Kpindou, A. Onzo, G. Goergen, O. Coulibaly,

C. Fatokun, O. Boukar, M. Ayodele, L. Kumar

In Africa

Benin: D. Arodokoun, INRAB; P. Atachi, FSA/UAC, A. Paraiso, UP, S. Saizonou,

SPV + several NGOs

Burkina Faso: C. Dabire and M. Ba, INERA

Ghana: H. Braimah, CRI, S. Asante, SARI; M. Kofya-Boamah, PPRDS

Niger: B. Ibrahim, INRAN

Nigeria: M. Dike, ABU; F. Pitan, UAbeokuta; N. Oigiangbe, UAkure

With other centers/advanced labs

AfricaRice: F. Nwilene, A. Togola

AVRDC: R. Srinivasan

icipe: N. Maniania

NRI: M. Downham

WAU: A. van Huis, M. Dicke

UGoettingen: S. Vidal

UIllinois: B. Pittendrigh, D. Onsted

UPurdue: L. Murdoch

Thanks to all my collaborators


Thanks to our sponsors

• CGIAR core donors

• SDC

• IFAD

• Gatsby Charitable Foundation

• BMZ

• DfID

• RDA South Korea

• Pulses-CRSP

• AATF

• McKnight Foundation

…and thanks to you all for your attention !

harnessing biodiversity for sustainable pest management

Technology

j u n u n2323j

j u n u n3030j u nj

different host plants

selected host plants

jujun n1616j

vitrata cypovirus mvcpv

host plant surveys

host plant resistance