CONTRIBUTION TO A BETTER UNDERSTANDING OF

FLIGHT PATTERN AND EGG-LAYING DURATION OF THE

PISTACHIO SEED WASP

Mohamed BRAHAM

University of Sousse. Laboratory of Entomology and

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Laboratory of Entomology and Insect Ecology. Regional Research Center of Horticulture and Organic Agriculture. 4042. Chott-Mariem.

Sousse. Tunisia.

Email :braham.mohamed@gmail.com

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PLAN

�INTRODUCTION�PROBLEMATICS�OBJECTIVES OF THE STUDY�MATERIELS AND METHODS

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�MATERIELS AND METHODS�RESULTS�CONCLUSIONS AND RECOMMENDATIONS

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THE PISTACHIO TREE, PISTACIA VERA

►Pistachio is a tree of great

interest for reforestation and

exploitation of poor lands.

► It is well adapted to various

climatic conditions and climatic conditions and

supports long periods of

drought

► It occupies larges lands

which are less appropriate or

even inappropriate for other

crops such as almond or olive

treesBRAHAM. GREMPA MEETING. MEKNES12-15MAY2015

THE PISTACHIO CULTIVATION IN TUNISIA

�Total cultivation area 4400 ha in 1980 to 43000 ha in 2002 (Onagri, 2015).

�The yield is very low averaging 28 kg per ha in 2002) 2002)

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PROBLEMS CONCERNING PISTACHIO CULTIVATION IN TUNISIA

� Dioecious tree : pollination required

� the lack of synchronization of flowering periods for male and

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for male and female trees

� pruning, irrigation, nutrition

� the attack of insects and pathogens

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KEY INSECTS ATTACKING PISTACHIO IN TUNISIA

►The Pistachio seedwasp: Eurytoma plotnikovi

►The pistachio seed chalcid: Megastigmus pistaciae

►The Scolytid : Chaetoptelius vestitus

BRAHAM. GREMPA. MEKNES12-15MAY2015

SPRING

WINTER

SUMMER

SUMMERAutumn -Winter

Diapausing larvae

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SPRING

Oviposition

Larval development

BRIEF BIOLOGY THE PISTACHIO SEED WASP EURYTOMA PLOTNIKOVI

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PROBLEMATICS

�E. plotnikovi destroys up to 70 % of nuts in some orchards without control

�The control of this pest is undertaken with a wide range of insecticides.

�Discrepancies on the optimal time to treat

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�Discrepancies on the optimal time to treat coupled with the difficulty of the monitoring the adult population has resulted in several sprays generally applied at unsuitable periods (usually in late May -June each year) and then are ineffective.

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OBJECTIVES OF THE STUDY

The contribution to the knowledge of the biology of Pistachio seed wasp

To determine the period of oviposition activity of females

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oviposition activity of females

in order to establish better control methods (Using contact insecticides to control adults or systemic insecticides to control larvae

Pistachio nutsLeft attackedRight Healthy

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MATERIALS AND METHODS

1. Monitoring the infestation and adult emergence

�From late April to early July in 2005, 2006 and 2011in 2005, 2006 and 2011

� Collection of 50 old nuts and 50 freshly formed nuts from at least 5 trees

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� Old nuts were split to record� Number of filled

nuts� Number of

unpollinated nuts� Number of mature

larvae, pupae, adultslarvae, pupae, adults� Number of nuts with

exit holes (emerged adults)

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Newly formed nuts were dissected in the laboratory and infestation was sorted on eggs, young larvae, developing larvae,

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developing larvae, old larvae

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� 2. Caged, un-caged pistachio nuts tests

� 24 Pistachio twigs bearing from 10 to more than 100 nuts were caged on April 30, 2005

� 1 marked twig, exposed continuously to natural infestation was used as a control.

1 twig caged on April 30 was left � 1 twig caged on April 30 was left continuously caged till the end of the experiment (July 30).

� Cages were sequentially removed (each one every 3 -5 days) and re-caged after 3 to 5 days. This period was devoted to allow wild females oviposition in the orchard

BRAHAM. GREMPA. MEKNES12-15MAY2015

RESULTS

1. Monitoring the infestation in the orchard (YEAR 2005)

20%

30%

40%

50%

60%

70%

80%

90%

100%

0%

10%

20%

15-A

pr-0

517

-Apr

-05

19-A

pr-0

521

-Apr

-05

23-A

pr-0

525

-Apr

-05

27-A

pr-0

529

-Apr

-05

1-M

ay-0

53-

May

-05

5-M

ay-0

57-

May

-05

9-M

ay-0

511

-May

-05

13-M

ay-0

515

-May

-05

17-M

ay-0

519

-May

-05

21-M

ay-0

523

-May

-05

25-M

ay-0

527

-May

-05

29-M

ay-0

531

-May

-05

2-Ju

n-05

4-Ju

n-05

6-Ju

n-05

8-Ju

n-05

10-J

un-0

512

-Jun

-05

14-J

un-0

5

Dates

Old larvae White pupae Colored pupaeAdults inside fruits Fruits with exit holes

Percentage of larvae, pupae, adults and empty nuts obtained by picking and splitting 50 nuts.BRAHAM. GREMPA. MEKNES12-15MAY2015

YEAR 2006

30%

40%

50%

60%

70%

80%

90%

100%

0%

10%

20%

15-A

pr-0

617

-Apr

-06

19-A

pr-0

621

-Apr

-06

23-A

pr-0

625

-Apr

-06

27-A

pr-0

629

-Apr

-06

1-M

ay-0

63-

May

-06

5-M

ay-0

67-

May

-06

9-M

ay-0

611

-May

-06

13-M

ay-0

615

-May

-06

17-M

ay-0

619

-May

-06

21-M

ay-0

623

-May

-06

25-M

ay-0

627

-May

-06

29-M

ay-0

631

-May

-06

2-Ju

n-06

4-Ju

n-06

6-Ju

n-06

8-Ju

n-06

10-J

un-0

612

-Jun

-06

14-J

un-0

6

Dates

Old larvae White pupae Colored pupae Adults inside fruits Fruits with exit holes

Percentage of larvae, pupae, adults and empty nuts obtained by picking and splitting 50 nuts.BRAHAM. GREMPA. MEKNES12-15MAY2015

YEAR 2011

30%

40%

50%

60%

70%

80%

90%

100%

0%

10%

20%

30%

30 April 2011

7 May 2011

10 May 2011

12 May 2011

16 May 2011

19 May 2011

23 May 2011

26 May 2011

31 May 2011

6 June 2011

14 June 2011

17 June 2011

21 June 2011

Dates

Old larvae White pupae Colored pupae Adults inside fruits Fruits with exit holes

Percentage of larvae, pupae, adults and empty nuts obtained by picking and splitting 50 nuts.BRAHAM. GREMPA. MEKNES12-15MAY2015

Dates Eggs on the inner part of the endocarp

Eggs on embryo

Total

27/04/2005 0 0 030/04/2005 0 0 004/05/2005 3 (100%) 0 307/05/2005 7 (87.5%) 1 (12.5%) 810/05/2005 23 (95.83%) 1 (4.16) 2414/05/2005 2 (66.66%) 1 (33.33) 317/05/2005 7 (100%) 0 (0%) 720/05/2005 7 (87.5%) 1 (12.5%) 824/05/2005 5 (83.33%) 1 (16.66%) 627/05/2005 7 (100%) 0 (0%) 7

2. Egg laying period characterization in the orchardB

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In 2005, the oviposition commenced on May 4 to take end on June 4, 2005 although, eggs were detected in nuts on July, 9 but in very small numbers .The maximum of eggs were deposited at around 10 May 2005

27/05/2005 7 (100%) 0 (0%) 701/06/2005 4 (100%) 0 (0%) 4

04/06/2005 2 (100%) 0 (0%) 209/06/2005 0 0 014/06/2005 0 0 023/06/2005 0 0 028/06/2005 0 0 002/07/2005 0 0 005/07/2005 0 0 009/07/2005 2 (100%) 0 (0%) 212/07/2005 0 0 0

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Dates Eggs on the inner part of the endocarp

Eggs on embryo Total

23 -April-06 0 0 025 -April-06 0 0 027-April-06 0 0 030-April-06 0 0 0

4-May-06 12 (70.60%) 5(29.4%) 17

7-May-06 5 (45.45%) 6 (54.55%) 11

10-May-06 12 (75%) 4 (25%) 16

14-May-06 7 (53,85%) 6 (46.15) 13

17-May-06 4 (80%) 1(20%) 5

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17-May-06 4 (80%) 1(20%) 5

20-May-06 5 (100%) 0 (0%) 5

24-May-06 4 (100%) 0 (0%) 4

27-May-06 5 (71.40%) 2 (28.60%) 71- June-06 0 0 04-June-06 0 0 09-June-06 0 0 014-June-06 0 0 0

In 2006, the egg laying period commenced on May 4 to finish at the end of the moth (27 May) with a maximum from 4 May to 14 May 2006

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Dates Eggs on the inner part of the endocarp

Eggs on embryo

Total

30/04/2011 0 0 0

07/05/2011 13 (68.42%) 6(31.58) 19

10/05/2011 5 (71.42%) 2(28.58) 7

12/05/2011 4 (80%) 1 (20%) 5

16/05/2011 10 (58.82) 7 (41.18) 17

19/05/2011 2 (100 %) 0 (0%) 2

23/05/2011 6 (100 %) 0 (0%) 6

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23/05/2011 6 (100 %) 0 (0%) 6

26/05/2011 2 (100 %) 0 (0%) 2

31/05/2011 2 (100 %) 0 (0%) 2

06/06/2011 0 0 0

10/06/2011 0 0 0

14/06/2011 0 0 0

17/06/2011 0 0 0

21/06/2011 0 0 0

24/06/2011 0 0 0

In 2011, the egg laying period was concentrated in May with a maximum occurring on 16 May, 2006

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3. Caged, un-caged tests Table. Dates of caged, un-caged and re-caged twigs as

well as the presence/absence of mature larvae of E. plotnikovi at harvest (22 August, 2005)

RESULTS

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0 = Absence of mature larvae of E. plotnikovi at harvest (August, 22, 2005)

1 = Presence of mature

Caged Un-caged Re-caged Presence/absence of E.plotnikovi larvae atharvest

30/4/05 4/5/05 7/5/05 030/4/05 7/5/05 10/5/05 130/4/05 7/5/05 10/5/05 030/4/05 7/5/05 10/5/05 030/4/05 10/5/05 14/5/05 130/4/05 10/5/05 14/5/05 030/4/05 10/5/05 14/5/05 030/4/05 10/5/05 14/5/05 030/4/05 14/5/05 17/5/05 130/4/05 14/5/05 17/5/05 030/4/05 17/5/05 20/5/05 0

YEAR 2005

1 = Presence of mature larvae of E. plotnikovi at harvest (August, 22, 2005)

* Continuously covered and opened on July 30, 2005

** Continuously exposed to natural infestation and served as a control

30/4/05 17/5/05 20/5/05 030/4/05 17/5/05 20/5/05 030/4/05 20/5/05 24/5/05 030/4/05 20/5/05 24/5/05 030/4/05 24/5/05 27/5/05 130/4/05 27/5/05 01/6/05 130/4/05 27/5/05 01/6/05 030/4/05 01/6/05 04/6/05 130/4/05 01/6/05 04/6/05 030/4/05 04/6/05 09/6/05 130/4/05 04/6/05 09/6/05 030/4/05 09/6/05 14/6/05 030/4/05* 0

30/4/05** 1BRAHAM. GREMPA. MEKNES12-15MAY2015

Caged Un-caged Re-caged Presence/absence of E.plotnikovi larvae at harvest

April, 26, May, 3, 2006 May,6 2006 0April, 26 May, 3 May, 6 0April, 26 May, 6 May, 8 1April, 26 May, 6 May, 8 0April, 26 May, 8 May, 11 0April, 26 May, 8 May, 11 0April, 26 May, 11 May, 13 0April, 26 May, 11 May, 13 0April, 26 May, 13 May, 16 0April, 26 May, 13 May, 16 0April, 26 May, 16 May, 18 0April, 26 May, 16 May, 18 0April, 26 May, 18 May, 20 0April, 26 May, 18 May, 20 0

YEAR 2006

April, 26 May, 18 May, 20 0April, 26 May, 20 May, 23 0April, 26 May, 20 May, 23 1

April, 26 May, 23 May, 26 1

April, 26 May, 23 May, 26 1April, 26 May, 26 May, 29 0April, 26 May, 26 May, 29 1April, 26 May, 29 June, 1 0April, 26 May, 29 June, 1 0April, 26 June, 1 June, 3 0April, 26 June, 1 June, 3 0April, 26 June, 3 June, 6 0April, 26 June, 6 June, 9 0April, 26 June, 6 June, 9 0April, 26 June, 6 June, 9 0April, 26 June, 9 June, 13 0April, 26 June, 9 June, 13 0

BRAHAM. GREMPA. MEKNES12-15MAY2015

CONCLUSION AND RECOMMENDATIONS• Adult flight : begins in late April, early-May and lasted to late May, early-June

•The oviposition starts at the beginning of May to last till the end of the month

•To be effective, sprays have to be •To be effective, sprays have to be taken during all the period of adult flight

- Encourage farmers to remove all nuts on and beneath the pistachio trees and destroy them before the end of the winter- The use of cage harboring old nuts in the orchard and monitor adult emergence BRAHAM. GREMPA. MEKNES12-15MAY2015

Many thanks are due to

-Mediterranean Institute Agronomic of Zaragoza (IAMZ)-- Ecole Nationale d’Agriculture de Meknès

-Professor Jean-Yves RASPLUS (INRA Montpellier, France) for the confirmation of the identification of E. plotnikovi.

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identification of E. plotnikovi.

-the former and current director of “the Higher Institute of Agricultural Sciences of Chott-Mariem” for permitting to use the Pistachio orchard.

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