Alberto Urbaneja, Óscar Mollá, Miquel Alonso & Joel González-Cabrera

Unidad de Entomología

UJI-IVIA-CIB CSIC

Basis for integrating Bacillus thuringiensisand Nesidiocoris tenuis for biological control

of Tuta absoluta

• The tomato borer, Tuta absoluta is a

devastating pest of tomato originating from

South America.

• At the end of 2006, T. absoluta was detected in

eastern Spain

• This pest is present throughout the crop growing

cycle.

• If no control measures are taken, then pest can

cause up to 80-100% yield losses in recently

invades areas.

Invasion of Europe and MediterraneanBasin countries

Invasion of Europe and MediterraneanBasin countries

From: Desneaux et al. 2010. J Pest Sci 83:197–215

Disruption of IPM in Spanish tomato greenhouses

• IPM based in biological control and use of

bumblebees for pollination

• After T. absoluta detection, the most common

control method was based in the use of chemical

insecticides. These treatments :

– disrupt the existing IPM programs in tomato

based on biological control.

– Residues, may lead to resistance, etc

• It was urgent to implement environmentally safe

measures to manage T. absoluta limiting the use of

chemical insecticides

Biological Control

• Since its arrival in the Mediterranean Basin, a set of endemic

natural enemies have been reported on T. absoluta.

• Their suitability for T. absoluta biological control is currently

being evaluated.

Parasitoids Predators Entomopathogens

Natural enemies reported in the Mediterranean Basin

From: Desneaux et al. 2010. J Pest Sci 83:197–215

Stenomesius sp.

Necremnus artynes

Hymenoptera: Eulophidae

Larva

Adult

Pupa

Other natural enemies

Braconidae

Vespidae

Nabidae

Trichogrammatidae Phytoseiidae

Ants

Macrolophus pygmaeus

Nesidiocoris tenuis

Efficacy of Bacillus thuringiensis (Bt) in controlling T. absoluta

• Several commonly used Bt

formulates reduced damage by

up to 98% in sprayed plants when

tested in laboratory assays.

• First instar larvae were the

most susceptible.

• Laboratory, greenhouse and open-

field experiments have evidenced

that Bt is highly efficient in

controlling T. absoluta

From: González-Cabrera et al. 2010. BioControl: In press

Control

Costar

Dipel

Xentar

i

Turex0

20

40

60

80

a

b b bb

A

Att

acke

d le

afle

ts/p

lant

Efficacy of Bacillus thuringiensis (Bt) in controlling T. absoluta

From: González-Cabrera et al. 2010. BioControl: In press

4,000 m2 tomato greenhouse Anecoop Museros (Valencia)

N. tenuis

Miridae as biocontrol agents

• Miridae commonly appear spontaneously and in large

numbers in protected and open-air tomato crops in the

Mediterranean region.

Miridae as biocontrol agents

• Miridae commonly appear spontaneously and in large

numbers in protected and open-air tomato crops in the

Mediterranean region.

• Zoophytophagous behavior and polyphagous

predator: they can make significant contributions to

control tomato pests as whiteflies, leafminers, trips and

spider mites.

N. tenuis

M. pygmeus

Miridae as biocontrol agents

• Miridae commonly appear spontaneously and in large

numbers in protected and open-air tomato crops in the

Mediterranean region (also used as inoculative BC).

• Zoophytophagous behavior and polyphagous

predator: they can make significant contributions to

control tomato pests as whiteflies, leafminers, trips and

spider mites.

• Nesidiocoris tenuis Reuter and Macrolophus

pygmaeus (Rambur) were detecting preying upon T.

absoluta within the first year of its arrival in the

Spanish Mediterranean region.

Miridae as biocontrol agents

• Miridae commonly appear spontaneously and in large

numbers in protected and open-air tomato crops in the

Mediterranean region.

• Zoophytophagous behavior and polyphagous

predator: they can make significant contributions to

control tomato pests as whiteflies, leafminers, trips and

spider mites.

• Nesidiocoris tenuis Reuter and Macrolophus

pygmaeus (Rambur) were detecting preying upon T.

absoluta within the first year of its arrival in the

Spanish Mediterranean region.

• In summer 2009, Dicyphus marrocannus Wagner

was also detected on preying on T. absoluta.

N. tenuis

M. pygmeus

D. marrocannus

Suitability of T. absoluta as prey for M. pygmaeus and N. tenuis

• Both predators preyed actively on T. absoluta eggs.

• Females consumed significantly more T. absoluta eggs than males

Male Female0

20

40

60

80 N. tenuisM. pygmaeus

# co

nsum

ed e

ggs

in 2

4 h

From: Urbaneja et al. 2009. J Appl Entomol 133: 292-296

Preyed by mirids

Healthy egg

L1 L2 L3 L40.0

0.5

1.0

1.5

2.0

2.5N. tenuisM. pygmaeus

T. absoluta Instars

# pr

eyed

larv

ae• Number of larvae preyed on was significantly much lower that the number of eggs preyed on.• Both predators most frequently preyed upon the first instar

Suitability of T. absoluta as prey for M. pygmaeus and N. tenuis

From: Urbaneja et al. 2009. J Appl Entomol 133: 292-296

Biology of Nesidiocoris tenuis preying upon T. absoluta

• N. tenuis is able to complete its development preying exclusively upon T. absoluta in aprox. 14 d.

0 1 2 3 4 50

20

40

60

80

100

T. absolutaE. kuehniellaControl

Chi= 41,53; P< 0,0001

Estadio ninfal

% S

urvi

val

Immature survival (25ºC, 60 10%, 16:8 h L:D)

From: Mollá et al. 2011a. Submitted

Immature prey consumption (25ºC, 60 10%, 16:8 h L:D)

Tuta absoluta Ephestia kuehniella0

50

100

150

200 t44 = 5.122; P < 0.0001

# co

nsum

ed e

ggs

Biology of Nesidiocoris tenuis preying upon T. absoluta

From: Mollá et al. 2011a. Submitted

Field observations

(2008-2009)• When mirids were established in the crop,

they were able to reduce T. absolutainfestations

N. tenuis

M. pygmeus

D. marrocannus

Field observations

(2008-2009)• When mirids were established in the crop,

they were able to reduce T. absolutainfestations

• Mollá et al. (2009. IOBC WPRS Bulletin 49:209-

214) showed:

– when N. tenuis and M. pygmaeus were established in the crop

0

2

4

6

8

10 Control

Macrolophus pygmaeus

Nesidiocoris tenuis

# m

irids

per

pla

nt

Field observations

(2008-2009)• When mirids were established in the crop,

they were able to reduce T. absolutainfestations

• Mollá et al. (2009. IOBC WPRS Bulletin 49:209-

214) showed:

– when M. pygmaeus and N. tenuis were established in the crop

– Reduction up to 75 and 97% of leaflet infestations 0

10

20

30

40

50 Control

Macrolophus pygmaeus

Nesidiocoris tenuis

# in

fest

ed le

afle

ts p

er p

lant

0

2

4

6

8

10 Control

Macrolophus pygmaeus

Nesidiocoris tenuis

# m

irids

per

pla

nt

T. absoluta release

Field observations

(2008-2009)• When mirids were established in the crop,

they were able to reduce T. absolutainfestations

• Mollá et al. (2009. IOBC WPRS Bulletin 49:209-

214) showed:

– when M. pygmaeus and N. tenuis were established in the crop

– Reduction up to 75 and 97% of leaflet infestations

– 56% and 100% of fruit infestations.

0

10

20

30

40

50 Control

Macrolophus pygmaeus

Nesidiocoris tenuis

# in

fest

ed le

afle

ts p

er p

lant

06/05

/2008

20/05

/2008

03/06

/2008

19/06

/2008

03/07

/2008

18/07

/2008

04/08

/2008

0.0

0.5

1.0

1.5

2.0 Control

Macrolophus pygmaeus

Nesidiocoris tenuis

# in

fest

ed f

ruit

s pe

r pl

ant

0

2

4

6

8

10 Control

Macrolophus pygmaeus

Nesidiocoris tenuis

# m

irids

per

pla

nt

T. absoluta release

Field observations

(2008-2009)• When mirids were established in the crop,

they were able to reduce T. absolutainfestations

• Mollá et al. (2009. IOBC WPRS Bulletin 49:209-214) showed:

– when M. pygmaeus and N. tenuis were established in the crop

– Reduction up to 75 and 97% of leaflet infestations

– 56% and 100% of fruit infestations.

• During 2009, Arnó et al. (2009. IOBC WPRS

Bulletin 49:203-208) observed in 281 tomato crops (either greenhouse or open fields) than when 4.5 mirids/plant were present in a crop, fruit damage remained below 4%.

0

10

20

30

40

50 Control

Macrolophus pygmaeus

Nesidiocoris tenuis

# in

fest

ed le

afle

ts p

er p

lant

06/05

/2008

20/05

/2008

03/06

/2008

19/06

/2008

03/07

/2008

18/07

/2008

04/08

/2008

0.0

0.5

1.0

1.5

2.0 Control

Macrolophus pygmaeus

Nesidiocoris tenuis

# in

fest

ed f

ruit

s pe

r pl

ant

0

2

4

6

8

10 Control

Macrolophus pygmaeus

Nesidiocoris tenuis

# m

irids

per

pla

nt

T. absoluta release

• The integration of B. thuringiensis treatments with the inoculation or conservation of these predators may provide a safe strategy to manage this pest (B. thuringiensistargets young larvae and mirids prey preferentially on T. absoluta eggs).

• Therefore, we hypothesize that B. thuringiensistreatments applied immediately after initial T. absolutadetection on plants, do not interfere with mirid installation in the crop since T. absoluta eggs are available.

• Afterwards, B. thuringiensis treatment could be withheld to leave mirids alone to control the pest.

Hypothesis: Combined use of Bt and mirids

Combined use of Bt and N. tenuis against the tomato borer T. absoluta

• In 2009, greenhouse divided into 12 experimental cages (10 tomato plants per cage).

• To simulate a strong a constant T. absoluta attack on the crop, each cage was weekly infested with 10 T. absoluta couples.

• 4 treatments were assayed:

• Control

• 2 months of weekly Bt sprays + inoculation of N. tenuis

• 3 months of weekly Bt sprays + inoculation N. tenuis

• weekly Bt sprays + inoculation N. tenuis

2010: commercial trials Bt & Nt

• During 2010 the combined use of Bt & N. tenuis has been tested under different commercial situations:

• Open fields (staked tomato)

• Greenhouses (plastic and mesh)

• Different strategies have been assayed.

• Very positive results in all crops evaluated.

Conclusions

• Inoculative releases of the predator N. tenuis combined with B. thuringiensis treatments have proven highly

effective in reducing the damage caused by T. absoluta.

• In addittion, when N. tenuis is installed in the crop it will help

controlling other pests, such as whiteflies, spider mites or

trips, while B. thuringiensis treatments will prevent damage by

other lepidopteran pests such as Helicoverpa armigera(Hübner).

• In summary, our results suggest that the combination of N. tenuis and B. thuringiensis, is a cost-effective strategy for

tomato crop pest management. Overall, this is an

environmentally safe strategy, which may provide a clean

tomato yield without chemical residues, thereby increasing fruit safety and quality.

Alberto Urbaneja, Óscar Mollá, Miquel Alonso & Joel González-Cabrera

Unidad de Entomología. UJI-IVIA-CIB CSIC

Basis for integrating Bacillus thuringiensisand Nesidiocoris tenuis for biological control

of Tuta absoluta

This work was partially funded by the Instituto Nacional de Investigación y Tecnología Agraria (INIA-CC09-048)

and the Conselleria d’Agricultura, Pesca i Alimentació de la Generalitat Valenciana

S�� ��� �� VALENCIA

N������� 2012

12th International Citrus Congress

ICC

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