IOBC Canada 2017 – Part I

Go back to Monday’s Agenda

Biological control in greenhouse IPM systems: Where we’ve been, where we are, and where we need to go?
by Michael Brownbridge

Greenhouse production:

  • Unique production environment
  • Many variables within the production system: crop, pest, production practices, and external environmental factors

Talk is on where Michael believes many of the challenges in biological control are (Canadian/NA perspective)

According to van Lenteren, <10% of available biologicals are used in greenhouse production

  • Very few new agents in last 20 years

Biocontrol systems fail due to:

  • Environmental conditions
  • Poor match between crop and natural enemy
  • Poor shipping conditions

New pest incursions on imported plant material

Simplification of bioprograms

  • Could one generalist replace several specialists?

At a time where we have strict regulations limiting importation of non-native species

‘Industrial’ model:

  • Centralized production, ‘global’ distribution

Perhaps instead of a ‘one-size fits all’ solution to production of natural enemies, we need more regional hubs of geographically unique species for that region:

  • Cater to more ‘local’ markets
  • Enhanced quality/efficacy
  • Less risk to supply?

In-house production (large greenhouse business):

  • Rear/supply for own use
  • Collaboration with like-minded consortium?

Ultimate question: how do you bring new natural enemies to the hands of the growers? Needs to be done with some flexibility:

  • Doesn’t need to be marketable biological control or easy to rear

Impossible to make sweeping generalizations – need to test in crop/conditions where needed.

  • Many of these crops share the same pests, but the same natural enemy will not work on the same pest if it’s on different crops
  • How do we use these natural enemies over these disparate crops and systems

Biological control works due to the contribution of several natural enemies

  • Compatibility essential

Biological vs functional

  • A lot of papers that look at biological control as a single biocontrol organism. But how does it work in a crop production system

Toxicity testing (ie insecticide compatibility):

  • Valuable, but only part of the story
  • Non-lethal effects?

Educating the gate-keepers

  • Need to engage the full range of gatekeepers, especially around new technology:
    • Regulators
    • Consultants and extension staff
    • Sales
    • End-users
  • How to use, what to expect
  • Function/contribution within IPM

We should be building resilient systems:

  • Right control agents
  • Right plant
  • Right environment
    • = Effective control

Production practices

  • Understanding potential side-effects of production practices
    • 50% reduction in fertilizer rate in mums reduced aphid populations by 1/3. Does not work in all situations but definitely worth exploring:
      • Many crops in floriculture are grown in high fertilizer regimes
      • In many crops can reduce fertilizer rate from 25 – 75% and not impact plant production
      • Save money on fertilizers, reducing likelihood of nutrient run-off into the environment

Traditional plant breeding has not considered plant pest and pathogen resistance

  • High likelihood we have lost a lot of these resistance traits in plants
  • Now there are more opportunities to breed resistance traits into plants and incorporate those into breeding programs

Plant-associated bacteria and fungi

  • Enhance growth
  • Induce plant mechanisms to protect against stress
  • ‘prime’ plants, elevated response to pests/diseases
  • Pest avoidance/reduce fecundity/slower development

Microbes, the next frontier?

  • Includes biopesticides
    • Applied to directly control pests/diseases
  • Biostimulants, biofertilizers, endophytes
  • How/what to commercialize?
  • Are responses large enough to be commercially-relevant?
  • How to deploy, ensure consistent impact

Biological control using invertebrates and microbes – paper by van Lenteren

Delivery systems will be something that increase efficiency of biological control

  • How and where to place the biological controls
  • Increase automation at all levels

Grower trials

  • Driven by curiosity, innate need to make things work in their greenhouse
  • Practical, tangible outcomes
  • Immediate impact
  • Pragmatic citizen science!
    • Why can’t we look at biological control as a citizen science?
    • Sometimes the trends in the data and efficacy in the field are more relevant than the points on a graph
  • How can we share?

The way forward?

  • Failure of traditional crop protection methods
  • Production
    • Improve production efficiency on same/less inputs
    • Increased production in protected structures
  • Environmental regulations
    • Across the board
  • Consumer-driven markets
    • Product differentiation to meet market demand
    • Eliminate residues/health awareness (informed or otherwise)
  • Supermarkets are demanding suppliers (in Europe) to decrease residues and placing requirements on crop quality (instead of government), and we may be headed in that direction

Go back to Monday’s Agenda

Innovative strategies that enhance the cost-effectiveness, reliability and efficacy of arthropod-based biocontrol in greenhouse crop
by Shimon Steinberg, BioBee

Production protocols affect intrinsic quality of the natural enemy (not just live/dead)

Multiyear trend of fecundity in mass-reared P. persimilis based on IOBC guidelines

  • Need to have at least two new females per day produced by a single adult
  • Last two years many more trials conducted and doing better and better in terms of number of females produced per adult
  • If grower releases and can’t see it afterwards, it has a lot to do with establishment of the mite

Mummies of Anagyrus sp. Near pseudococci.

  • Adults used to be delivered and didn’t survive well
  • Now deliver (and can be stored) as mummies and get very good emergence rate even after up to 3 weeks in storage at 12C

Selective breeding of natural enemies

  • Effect of temperature and relative humidity on young stages of P. persimilis feeding on two-spotted spider mite on bean
  • Do well in lab conditions but not in field conditions (i.e. higher temperature = much lower fecundity)
  • Found P. persimilis better adapted to hot and dry conditions

Logistics, storage, transport and shipment

  • Used to deliver orius in bottles, 500 individuals per bottle, then increase to 1000. Found large mortality in the 1000 orius bottle, and the theory is due to carbon dioxide build-up. Decreased mortality by adding some ventilation into the crap

Formulation

  • Vermiculite, buckwheat, bran, grinded corncobs, wood chips

Delivery and release

  • Honey as a source of carbohydrates to parasitic wasps and ladybeetles
  • Bug blowers; whole new world where several producers have developed
  • Sachets; continuously new sachets coming onto the market
  • Preventing ants from attacking a mummy product
    • In a three stage process, open a sticky surface that prevents the ants from accessing the mummies

On the crop

  • Alternative food
    • Pollen; nutrimite, based on cattail pollen to feed predatory mites
    • Dead, inactivated prey (Artemia decapsulated cysts, medfly eggs, Ephestia eggs). Inactivated by freezing (shipped with dry ice)
  • Live prey to support predatory mites
  • Agrobio – Astigmatic mites
  • Dust mite’s eggs mixed with gel

Open rearing systems:

  • Banker plants (for aphid parasitoids, Orius spp., Mirid bugs, Aphidoletes)
    • Major problems is often maintenance of the banker plants (at least in Israel)
  • Mulch layers support development of astigmatic mites and, as a result, increase soil dwelling predator mites

Behavior manipulation

  • Pheromone of the vine mealybug is attracting A. sp. near pseudococci to the citrus mealybug (Franco et al. 2011)
  • Associative learning as a means to improve efficacy of citrus mealybug parasitoids in rose greenhouses (L. Vet, O. Kostenko…)

Other special needs

  • Pest-in-first system: spider mites and P. persimilis in greenhouse sweet pepper. Now in tomato (experimental, BioBee)
    • Introducing the spider mites in the greenhouse with P. persimilis in specific places to start building P. persimilis populations before bigger spider mite populations come in later in the season
  • Interplant bridges (flagging tape) to enhance dispersal of P. persimilis in greenhouse cut roses (Casey & Parrella, 2001). Now in tomato (experimental, BioBee).

Technical Advice

  • Scouting and monitoring. Apps for record tracking, reporting, analyzing
    • Analyzing historical data
  • Technologies for remote analysis, remote sensing

Side effects of pesticides

  • Inherent component in every information packet provided to the grower
  • Note!! Not just direct, indirect and persistence effects. Look for physiological, behavioral sub-lethal effects.
    • Looking at some of these inhouse at BioBee at the population level

Take home message

  • “All roads lead to Rome”
    • All of these items are a factor. No one factor is more important to the other.
  • Name of the game: Collaboration. Academia, extension, industry, practitioners

Go back to Monday’s Agenda

What secret holds the fog? Testing the fate of biologicals from the nozzle to the plant surface
by Michael Brownbridge, Vineland Research and Innovation Center

Fungal bio-pesticides: Beauveria bassiana

Biofungicide: Bacillus subtilis

  • Applied by spraying
  • Good coverage essential for successful insect or disease control
  • High volume hydraulic sprayers
    • Spray droplets 600 microns in diameter
  • Low volume mist (LVM) sprayers
    • Cold foggers
    • Thermal foggers
    • Spray droplets ~10 – 70um diameter

Smaller droplet size holds less conidia, but gets better coverage

  • 600 um droplet; 6220 conidia
  • 25 um; 2 conidia

Can apply by active spray (have to go around and deliver the spray to the plants yourself)

Advantages of LVM sprayers

  • Less liquid (carrier) to achieve the same coverage
  • More even coverage, reach areas missed by high volume sprayers (e.g. under leaves)
  • Eliminates run-off
  • Less time needed to treat large area
    • Don’t need applicator sitting there applying it.
    • Switch on the outside of the greenhouse that turns the system on and uses horizontal fans to distribute the fog
  • Many systems automated – worker health and safety

Disadvantages of LVM sprayers

  • Limited information on use for microbials
  • Mechanisms used to create spray droplets involve
    • High pressure
    • Heat
    • Percussive forces
  • Potential for mechanical/heat damage to conidia/spores

Does the fogging process affect the viability of conidia/spores?

Dramm Mini AutoFog, K-22 BIO Portable PulsFOG, and thermal fogger

  • Sampled solution from the tank before spray, material collected from the fog, and material collected from plants (and tank again after spray)

Processing of all samples

  • Viability – germination (B bassiana only)
    • On SDA (growing media) at 25C at 18h, 24h, and 36h
  • Conducted colony forming unit counts (CFU)
    • SDA + antibiotics (B bassiana)

Mini AutoFog:

  • No negative impact on conidia

K-22 BIO PulsFOG

  • About 90% of the conidia were killed in the process
  • B. Subtilis were ok on the other hand; they were much more resilient in this process
  • Factors that may affect viability
    • Combustion chamber; multiple explosions happening to atomize particles
    • Active ingredient mixes downstream; where there is heat, could be combustive force
  • Cold fogger safe for Botanigard, Cease
  • K-22 Bio PulsFOG unsuitable for Botanigard
  • Bacillus subtilis spores more robust, survive through PulsFOG
  • Possible to use larger injector nozzles to protect conidia?
  • Important to select the right equipment for application of biopesticides

Go back to Monday’s Agenda

A new method for loading predatory mites with entomopathogenic fungi for biocontrol of their prey
by Gongyu Lin, Institut de recherche en biologie végétale de l’Université de Montréal

  • Use mites and arthropods as vectors of entomopathogens for crop pests
    • Amblyseius swirskii has been used to disperse Beavaria bassiana to psyllids
    • They are here solely to spread the spores, since only first stages of psyllids are vulnerable to A. swirskii

Research Question:
Is it commercially possible to load predatory mites with spores?

  • Can we load predatory mites with entomopathogens

System: Western Flower Thrips

Entomopathogenic fungus:

  • B bassiana strain ANT-03
  • B bassiana cannot reach the thrips when sprayed

Three vector candidates:

  • A. swirskii, N. cucumeris, and S. scimitus (soil-dwelling species)

B. bassiana ANT-03

  • No impact on first instar, most effective against adults thrips, and some control on other stages

Mixed conidia with mite rearing substrates

  • Isolated mites with conidia in Eppendorf tubes for 2h, 8h, 20h, and 24h
  • Extracted mites from substrate, washed the mites, and counted how many spores were carried. Wash fluid was plated and counted number of colony forming units

Conidia retention increased only for S. scimitus with time

  • The more time they were exposed to the B. bassiana, the more colony forming units were retrieved
  • Other two species: B. bassiana accumulated to maximum carrying capacity within 2 hrs
  • B. bassiana affected survivorship of cucumeris
  • Strain is benign towards scimitus and swirskii, but pathogenic against cucumeris
  • A suitable pathogen-vector-host association
    • Using predatory mites to increase host encounter rate
    • In commercial rearing substrates, B. bassiana can accumulate on the body of predatory mites

Go back to Monday’s Agenda

Go to IOBC Canada Part II

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