Aphid control in pepper

Transcription

1 Aphid control in pepper Jeroen van Schelt Koppert Biological Systems

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3 Tobacco aphid or Red Myzus Myzus persicae nicotianae Dense colonies in top

4 A. solani gives strong allergic reactions from the plant

5 Problems: Chemicals for control of aphids are extremely cheap Full bio control is mainly used at eco growers (40 ha in NL), but cost will be often more than 4 euro /m2 of which 90% is for aphid control. Conventional growers use bca against aphids from January-June, but often stop because of problems with hypers Goal Can we find an effective solution against aphids for less than 1 euro/m 2? Driving forces Resistance to chemicals: pymetrozine (Plenum), or banned in near future: Imidacloprid (Admire), Pirimicarb (Pirimor) Stricter demand from supermarkets

6 Available beneficials Aphidius colemani Aphidius ervi Aphelinus abdominalis Aphidoletes aphidimyza Chrysoperla carnea Episyrphus balteatus Adalia bipunctata (Verticillium lecanii) bankerplants

7 Aphid development in pepper with two release strategies for A. colemani (Illustrative data set) aphids / m damage treshold (theoretical) weeknumber 0 A. colemani / m 2 Aphids (reactive) Aphids (preventive) Aphidius (reactive) Aphidius (preventive) total 22 A.colemani total 15 A. colemani

8 (a) (b) (c) Examples of empty mummies. a en b Aphidius sp c hyperparasitoid Dendrocerus aphidum (hyperparasitoid)

9 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% primary parasitoids P. villosa A. suspensus D. aphidum Seasonal abundance of 3 species of hyperparasitoids from aphid parasitoids in 10 greenhouse locations.

10 Message Start immediately after planting with releasing parasitoids Try to minimize number of mummies to prevent building up hypers Bankers are not necessary

11 Predators Aphidoletes aphidimyza (Gall midge)

12 Aphidoletes aphidimyza /APHIDEND adult eggs larva pupa

13 - Amblyseius swirskii + Amblyseius swirskii Aphidoletes aphidimyza against Myzus nicotianae. Messelink et al. Biol. Control. 2011

14 Message Swirskii in pepper can have a negative impact on eggs of Aphidoletes Better release high numbers (5-10/m2) of Aphidoletes once, than trickle it in. (Do not feed the mites ) With high release levels Aphidoletes is forced to lay more eggs at a colony of aphids

15 ??? Complicated food web Positive and negative interactions How to simplify?

16 Without Macrolophus With Macrolophus

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18 Predation rate by Adult Macrolophus Predation by M. pygmaeus in 24 hrs on 30 aphids (in petridishes) 1 1st instar 3th instar Adult 0,9 0,8 0,7 0,6 A a A a A a A a 0,5 0,4 0,3 0,2 0,1 0 B b A b BC A AC c c c A. solani M. euphorbiae M. persicae M. persicae nicotianae AB b B b D b

19 Cage trials, curative releases of Mirids A. Untreated B. Macrolophus pygmaeus C. Dicyphus errans D. Deraeocoris pallens E. Dicyphus tamaninii Rearing failed: Anthocoris nemorum, Deraeacoris ruber, D. schach, Dicyphus flavoviridis

20 Curative

21 Cage trials, preventive release of Mirids A. Untreated B. Macrolophus pygmaeus C. Dicyphus errans D. Deraeocoris pallens E. Macrolophus pygmaeus + food F. Dicyphus errans + food G. Dicyphus tamaninii + food H. Deraeocoris pallens + food Week 1 and 3: 8 pairs/cage Food= Ephestia eggs +Artemia Aphids intoduced in week 7,8,9

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23 Voedsel (mix artemia en ephestia) op de bladeren

24 Conclusions Mirids can not control aphids curatively When build up preventively, M. pygmaeus can keep the crop clean of aphids M. pygmaeus can prey and reproduce on all aphid stages Further observations and plans: Releases at the plant grower were already done successfully, but should be repeated Regular feeding to be optimized and economized Combinations with aphid parasitoids are still advised Good impact on eggs of noctuids

25 Future developments Secundary endosymbionts in aphids Regiella insecticola Defense against pathogenic fungi (and parasitoids?) Serratia symbiotica Defense against heat stress and parasitoids Hamiltonella defensa Defense against parasitoids (by means of a phage)

26 Gel Electrophoreses PCR loopt door een argarose gel 1% agarose TBE buffer

27 A. pisum infected First survey of endosymbionts in greenhouse aphids in the Netherlands

28 A. ervi tested on two A. pisum lines

29 Results

30 Conclusions and plans Hamiltonella is wide spread in all aphid species in Dutch glasshouses Impact on current parasitoids needs to be tested I foresee that the screening of aphids on endosymbionts and the performance of parasitoids will become a very useful tool in biocontrol in the near future

31 Biocontrol in roses a challenging system

32 The challenges Pests Spider mites Thrips (WFT, Echinothrips) Whiteflies Mealybugs and scales Low thresholds

33 Spider mites (Tetranychus urticae) Phytoseiulus persimilis Neoseiulus californicus Feltiella acarisuga

34 Biocontrol agents for thrips and whiteflies Against thrips Neoseiulus cucumeris Macrocheles robustulus Stratiolaelaps scimitus Against thrips and whiteflies Amblydromalus limonicus Amblyseius swirskii Transeius montdorensis Against whiteflies Encarsia formosa Eretmocerus eremicus Delphastus catalinae

35 How can we get sufficient predatory mites into the crop? Regular releases By hand Blowers Slow release sachets Additional food Pollen Prey mites Alternative prey on the soil Others?

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37 Mixes of several beneficials. Number of holes and turning speed determines dosage Impossible to enter

38 Very even distribution and 90% save in labor

39 Amblydromalus limonicus Strong numerical response at high pest levels (high predation rate) Feeds on eggs, crawlers, L1, L2 and L3 of whiteflies Feeds on L1 and L2 of thrips Effective at lower temperature ranges (13-20 o C) where A. swirskii reproduces slowly or not at all

40 Whitefly and thrips control in roses A. limonicus, A. swirskii, T. montdorensis, untreated control 3 releases of 100, 100 and 50 adult T. vaporariorum per cage on Day 0, 7 and young egg-laying female predatory mites released per cage on Day 4 Weekly monitoring of whitefly and phytoseiid populations

41 Phytoseiid population

42 Whitefly population

43 Thrips population

44 Swirski-Mite Plus and Swirski-Mite LD: Number of A. swirskii leaving the sachets in the first 6 weeks

45 Which strategy should we use? Which pests are present? Variety Pesticide use If Echinothrips is present: A. limonicus If P. ulmi is present: A. limonicus High whitefly pressure: A. limonicus (+ parasitoids) Dense crops: A. swirskii (Swirskii-Mite LD) Mites in sachets better protected against pesticides

46 Mealybugs and scales Tolerance low Mainly controlled with pesticides Biological control difficult Natural enemies of mealybugs

47 Set up 4 commercial rose growers (Red Naomi) Approx m2 research part 20 Chrysoperla larvae /m2 /week Rest of the greenhouse : chemically Monitoring Marking 8 hot spots Counting adult females and crawlers (2 minutes) Count every two weeks the same hotspots

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50 Results Good impact of larvae on the mealy bugs. None or only a few chemical sprays until summer ( normally every week!) Beginning of summer also adult lacewings (need to be identified) in greenhouse and some reproduction One grower stopped. Plans Bringing in Cryptolaemus larvae for hot spot treatments and further stabilization of the system

51 Thank you for your attention!