Aphids wreak havoc on gardens all over the world by gnawing holes in leaves and ruining crops. In cannabis farming, there’s one predaceous insect that slays them in a way that conjures images of the movie “Alien.” A parasitoid (aphidius colemani) lays its eggs inside the bodies of aphids. When they hatch, the parasitoid ruptures the aphid, killing it on the spot, and the new babies begin a life cycle that involves seeking and destroying aphids as part of its reproductive process.
This scenario plays out time and again under the cannabis canopies at greenhouse farms throughout Carpinteria Valley. Not all beneficial insects go about their work in as graphic a fashion as the parasitoid, but the millions of beneficial insects applied to the plants serve as the front lines on an endless microscopic battlefield.
Some beneficial insects like Swirskii, spend their lives eating the insects who eat the plants.
“Swirskii are the star player,” said Ivan Van Wingerden, owner of Coastal Blooms. “As a generalist predator, they are able to feed on different pests, which makes them very useful in a full biological program.”
Strict testing on cannabis to the level of parts per billion mandated by the state makes it next to impossible to apply pesticides to the crop. Cannabis farming has become ground zero for pest management using only beneficial insects. At Coastal Blooms, the weekly expense for beneficials— the good bugs who eat the bad ones—runs about $12,000, according to Van Wingerden.
“Using beneficials isn’t new to me or our farm,” Van Wingerden said. “We incorporated them in the Integrated Pest Management plan we had for gerberas, but with cannabis it’s 100 percent beneficials, so we’re constantly monitoring bug populations.”
According to Cannabis Association for Responsible Producers, or CARP Growers, greenhouses converting space to cannabis have to be completely scrubbed for historical pesticide use.
“We had to go to great lengths cleaning up all of these toxic residues from non-cannabis crops,” said Anthony Staal, who sits on the CARP Growers board. “From the ceiling glass to the soil we had to scrub down the whole greenhouse, remove all the old fixtures and apply new ground covers.”
Companies like BioBest, Koppert and BioLine, producers of beneficial insects, are enjoying a whole new market brought upon by California’s strict regulations on cannabis.
“It’s really cutting-edge,” said Harman Gilbert, Technical Sales Manager for BioBest. “Cannabis farming in California is leading the world in the use of beneficials. Of course, our company enjoys it for the boost to the bottom line, but we also see it as a potential game changer. By applying strictly beneficials on this scale, we are expanding pest control possibilities, reducing the uglier chemicals out there, and hopefully creating a model for cleaner agriculture across the board.”
Gilbert explained that it’s not as simple as throwing a bunch of insects into the mix that will eliminate harmful pests. There has to be a balance that keeps both populations in check. If the population of crop-damaging insects gets too high, then the plants suffer. If it’s too low, then beneficial insects lose their food source and die off, which will lead to a spike in the bad bug population.
“The insects, both good and bad, are present on the plants all the time,” Van Wingerden said. “Monitoring and managing bugs, many of which cannot be seen with the naked eye, is a daily pursuit with constant learning and adjusting. We don’t have the option of nuking them with some pesticide and being done with it.”
Companies like BioBest have varied delivery systems for applying beneficial insects. Living beneficial insects can be deployed directly to trouble spots. They’re shaken on to the canopy and get to work immediately. Beneficial insects also can be applied as eggs in small pouches with slits in them. They are hung on the plants and beneficial insects emerge from the pouch over time to seek out their prey. In some areas of the state BioBest applies beneficial insects to row crops using drones.