Applied Bio-nomics strongly suspected there was a better way and decided to go with instinct instead of what was fashionable
In a paper dated November 4th, 2005, one of our producers, Applied Bionomics Ltd., explained the advantages of “fresh” Encarsia formosa. We’ve been aware of this for awhile, and the rearing/shipping practice has been in effect a long time, but finally, now that the research findings are in, it’s time to spread the word.
In early 2001, Applied Bio-nomics approached Canagro Greenhouses in Delta, British Columbia, Canada, to determine their willingness to try something fresh and new — literally. Namely they wanted the grower to try a freshly-produced E. formosa on their greenhouse tomatoes for that season. Canagro was willing and excited by the prospect so, beginning with very clean greenhouses the trials commenced. Canagro was the perfect choice because they were located close by and they had excellent scouting and monitoring practices.
To back up a little and provide explanation, prior to this, all E. formosa was held to ensure the parasitoids were emerging upon arrival to the end user. The reason was simple: This is what growers wanted. Instant gratification. Moreover, since the rest of the worldwide supply was being produced — as it still is — in Europe and beyond, one- and two-week-old E. formosa was (and remains so) considered the norm. The trouble is, this practice isn’t in the best interest of the growers, even if it’s what they think they want. The cold storage affects these parasitoids, many parasitoids in fact, in some strange ways — like Trichogramma species, for example, which un-learn some of their abilities if cold-stored too long. Though it was unproven at the time, Applied Bio-nomics strongly suspected there was a better way and decided to go with instinct instead of what was fashionable. It’s one of the reason we like them. They’re straight shooters.
Here’s what they determined: Fresh E. formosa has a reduced emergence of 10% on average. This, however, is due to stored hanging cards — which is how they are supplied — losing pupae being “blown” off the cards. In other words, since older product has fewer pupae from literally falling from the cards as they dry out, the percentage of emergence is higher, mathematically-speaking.
Since Canagro was “clean” to start, they begin trials using one-half (½) parasitoid per every square meter of planting space every week beginning in January. This went on until summer. By that time some whiteflies were being located in the greenhouses. This is normal, it was expected, and the parasitoid release rate was increased to one (1) wasp per every square meter, in response to the influx. The trials went well. Of all the treated greenhouses, only one located downwind and very close to an untreated “control” greenhouse had anything close to significant number of whitefly pests. Success!
In 2002, they did it again, this time starting with half the rate as the prior year: one-quarter (¼) parasitoid per square meter. By late spring this time, instead of summer, the whiteflies showed up and parasitoid numbers needed to be increased. Still, Canagro was very pleased and so was Applied. These were great results!
In 2003, the decision was made to go ahead, based on these findings, and start producing only fresh E. formosa for all clients, even those in the United States and Europe. They refer to it as “Encarsia Max” (though the name hasn’t been adopted). Not cold-storing and artificially delaying the product has had a very positive effect, in an odd sort of way. Growers were less satisfied with the emergence — which caused us a lot of grief with one grower in particular who must count everything, but even they had the best whitefly year they had ever had. They used fewer wasps and spent far less money. They no longer gripe about rates (emergence takes longer now, though), and now after a couple of years of seeing their own results, they’re more pleased than ever with the world’s freshest Encarsia formosa. It makes sense, doesn’t it? Barring wine and cheese, fresh is generally best. For the complete white paper, please contact us with your request.
