Q and B biotypes– distribution, crop-relation, and their relevance … · 2018. 12. 5. ·...

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Q and B biotypes Q and B biotypes distribution, distribution, crop crop - - relation, and their relevance relation, and their relevance to insecticide resistance to insecticide resistance B B Q Q Rami Horowitz, Rami Horowitz, Svetlana Kontsedalov, Svetlana Kontsedalov, Vadim Khasdan Haggai Breslauer Vadim Khasdan Haggai Breslauer and Isaac Ishaaya and Isaac Ishaaya ARO, Dept. of Entomology, Gilat Research Center The Volcani Center, Bet Dagan, Israel

Transcript of Q and B biotypes– distribution, crop-relation, and their relevance … · 2018. 12. 5. ·...

  • Q and B biotypesQ and B biotypes–– distribution, distribution, cropcrop--relation, and their relevance relation, and their relevance

    to insecticide resistanceto insecticide resistance

    BB QQ

    Rami Horowitz, Rami Horowitz, Svetlana Kontsedalov, Svetlana Kontsedalov, Vadim Khasdan Haggai Breslauer Vadim Khasdan Haggai Breslauer

    and Isaac Ishaayaand Isaac IshaayaARO, Dept. of Entomology,

    Gilat Research CenterThe Volcani Center, Bet Dagan, Israel

  • biotype B biotype Q

    Two biotypes of B. tabaci have been identified in Israel:

    B B -- (early 1990(early 1990’’s)s)Q Q -- (2000) (2000)

  • RAPD-PCR products of various Bemisia tabaci strains from Israel

    1 2 3 4 5 6 7

    Lane 1Lane 1-- DNA ladder; 5DNA ladder; 5-- a sample without DNAa sample without DNA

    Lanes 2, 4, 7Lanes 2, 4, 7-- samples from samples from SdeSde--EliyahuEliyahu, w, w--Negev & standard BNegev & standard B

    Lanes 3, 6 Lanes 3, 6 –– samples from the Carmel Coast & standard Qsamples from the Carmel Coast & standard Q

  • Biotypes ofBiotypes of B. tabaci B. tabaci in Israel, 2002in Israel, 2002--55

    B

    Q,b

    Q,bQb

    B

    B

    Q

    B

    Bqq

    Q,B

  • Crossing studies, Q/B (field strains)Crossing studies, Q/B (field strains)Offspring Parents

    Sex ratioFemale: Male

    Males FemalesMales 40

    Females 20

    1.0 :0.7206360Negev (B)Negev (B)

    0.0:1.02450Arava (Q) Negev (B)

    1.0:0.7316458Arava (Q)Arava (Q)

    0.01:1.05036?Negev (B)Arava (Q)

  • In the Arava Valley (Israel); biotype In the Arava Valley (Israel); biotype survey was conducted during 2004survey was conducted during 2004––5 5

  • Organic vs. conventional crops

    • In the Arava Valley (Israel); biotype survey was conducted during 2004 – 2005.

    • Greenhouse organic peppers, cucumbers and melons – B.B.

    • Conventional greenhouses – Mostly QQ

  • Proportion of B. tabaci biotype Q and B sampled from sunflower and cotton fields during 2005

    cotton season in the Ayalon Valley, Israel

    May-3 May-31 June-19 Yuly-18 Aug-24Date

    40

    60

    80

    100

    120

    Perc

    ent

    Q

    Sunflower Cotton

    Endosulfan 'Polo' Cypermethrin

    Av-05

  • May-31 June-21 July-18 Aug-24Date

    0

    20

    40

    60

    80

    100

    120

    Perc

    ent Q

    Sunflower cotton

    Endosulfan 'Polo'Endosulfan

    HC-05

    Proportion of B. tabaci biotype Q and B sampled from sunflower and cotton fields during 2005

    cotton season in the Carmel Coast, Israel

  • Biotype tolerance to insecticides Biotype tolerance to insecticides affects their field compositionaffects their field composition

    AA BBB B QQ

  • Various populations of Various populations of Bemisia tabaciBemisia tabaci collected in Israel, collected in Israel, their biotype definition and resistance to pyriproxyfentheir biotype definition and resistance to pyriproxyfen

    Resistance (RR)

    BiotypeLocation Collection date

    Strain

    1BTzor’a1987S *2BW- Negev1999Yesha-99 4BBet Dagan2000BD-00

    0.4BW- Negev2000Negev-009BBet She’an2000BS-00

    1,200QGH, W- Negev1991Pyri-R*637QCarmel Coast 2000HC-00167Q>bAyalon Valley1999AV-99 81Q>bAyalon Valley2000AV-0025Q>bW- Galilee2000W-Gal

  • B

    QQ

    Early Early seasonseason Late seasonLate season

    0.0001 0.001 0.01 0.1 1 10 100 10001

    510

    30

    50

    70

    9095

    99

    S

    2002LS

    2003ES

    2003LS

    HC-03-tigConcentration (ppm)

    Egg

    mor

    talit

    y (%

    )Monitoring pyriproxyfen resistance, Monitoring pyriproxyfen resistance,

    Carmel Coast 2002Carmel Coast 2002--33

  • Resistance to Pyriproxyfen Resistance to Pyriproxyfen and biotype Qand biotype Q

    In areas where the use of pyriproxyfen ceased, resistance levels declined to some extent,while…Level of susceptibility was restored completely in the lab (gen. 15-20).

    Biotype-related resistance?

  • Monitoring Pyriproxyfen Monitoring Pyriproxyfen Resistance, Ayalon Valley, IsraelResistance, Ayalon Valley, Israel

    0.001 0.01 0.1 1 10 100 1000

    Concentration, ppm

    1

    510

    30

    50

    70

    9095

    99

    Egg

    mor

    talit

    y, %

    S

    1996

    2001

    2002

    2003

    2004

    2005

    S

  • Lab assaysLab assays

  • 0.0001 0.001 0.01 0.1 1 10 100 10001

    510

    30

    50

    70

    9095

    99S

    Unt

    Act

    Msp

    G0

    Tiger-Sel-02-15g

    Egg

    mor

    talit

    y (%

    )

    Concentration (ppm)

    Susceptibility of Susceptibility of B. tabaciB. tabaci strain (AVstrain (AV--02) to pyriproxyfen02) to pyriproxyfen

    Laboratory conditions (15Laboratory conditions (15thth generations)generations)

    BBBB

    QQ

    Q>B

    UntUnt=untreated=untreated;; G0 =the original G0 =the original strainstrain;;;;SS=susceptible =susceptible ;;(thiamethoxam)(thiamethoxam) Act=selection to ActaraAct=selection to Actara

    MspMsp=selection to Mospilan (acetamiprid)=selection to Mospilan (acetamiprid)

  • 0.001 0.01 0.1 1 10 100

    Concentration, ppm

    1

    510

    30

    50

    70

    9095

    99

    Egg

    Mor

    talit

    y, %

    S- Strain

    1st Gen.

    Untr.

    Pyri-Sel.

    mix-G20

    Mix of Q&B (1:1, with similar R) maintained for 20 generations; partly pressurized with

    pyriproxyfen; another part - kept untreated

    B

    BQ

    B

    B&Q

  • Proportion of B. tabaci biotypes throughout the generations

    PyriPyri--selectionselection

    untreateduntreatedGeneration Generation

    1B:1Q1B:1QG-0

    1B:1QBG-4

    Q>BBG-8

    QBG-12

    QBG-16

    QBG-20

  • Interaction ofInteraction of B. tabaciB. tabaci BiotypeBiotype

    1. Both the B and Q biotypes are present in Israel2. Field populations may consist of a mixture of

    biotypes3. Reproductive incompatibility maintains their

    genetic isolation4. A possible link exists between B. tabaci

    biotypes and insecticide resistance5. Tolerance of Q-type to pyriproxyfen,

    neonicotinoids and other new insecticides (?)6. Without exposure to insecticides – higher

    fitness to “B” (?)7. Insecticide applications select for Q-type.

  • We can surmise the following scenarioAppearance of Q biotype accompanies resistance to pyriproxyfen and/or neonicotinoids.

    Treatments in accordance with IRM programs moderate selection for resistance to those insecticides and concurrently reduce the appearance of the Q-type.

    Reuse of the above insecticides against B. tabacimay increase occurrence of the Q-type and development of resistance to one or another group of insecticides.

    (Selection to insecticides in B biotype of B. tabaciis feasible, but it is probably slower than in the Q type).

  • Unsolved questions

    1. Does B-type have higher fitness than Q-type (is it more competitive)?

    2. Why does “B” take over “Q” after several generations under lab conditions?

    3. Reproductive barrier: attraction, mating behavior, fertility, symbiont related?

  • QQBB