Dr. Norman C. Leppla
Photo courtesy of University of Florida

Greenhouse Management spoke to Dr. Norman C. Leppla, professor and program director, IPM at the University of Florida’s Entomology and Nematology Department about questions to ponder when considering biocontrol options.

Greenhouse Management: What is the one of the main points that growers should consider before beginning a biocontrol program?

Norman Leppla: Choosing a well-established supplier with a solid track record of serving customers is of utmost importance. Excellent customer service will be key as you begin and go through a biocontrol program. A good supplier will make sure you’re using their products appropriately. They’ll be upfront about availability and cost. And they’ll provide descriptions of target pests and their biology, as well as recommendations for applying and evaluating their products. They should provide the habitats and seasons in which the pests are encountered, developmental stages that are susceptible to parasitism or predation and relevant behavior of the natural enemies. 

GM: What is the first step when considering or adopting a biocontrol program?

NL: The first step is commitment and trying it one season is not enough. That’s another reason you need good-quality customer service from your suppliers. You must commit to a different system that involves cultural practices; sanitation (you must control the movement of things in and out of the greenhouse, including people); scouting; and being very careful of the source of your plants. You must commit to a system that’s biologically based and integrated.

GM: What are some common mistakes that growers make when adopting a biocontrol program?

NL: There are two mistakes that often occur – growers only conduct short-term trials. Like I said, trying it only one season is not enough. The other is when a grower takes the DIY approach and doesn’t enlist the help and expertise of their suppliers or when they try to rear their own natural enemies. I know a few growers who rear their own natural enemies, but it takes time to gain the experience.

Another common mistake is when a grower thinks of biocontrol as the same system as chemical control. They may think they’ll just remove the chemical and just add the biological, which is not the case whatsoever.

GM: Once a grower receives natural enemies from a supplier, what should they do first?

NL: Sometimes temperature extremes or other problems occur during shipping, so growers should open packages immediately to detect any potential issues and to provide a more hospitable environment for the natural enemies. Look for condensation or a fermenting smell, and the number of living and dead organisms should be estimated.

The University of Florida IFAS Extension produced a publication that offers guidelines for purchasing natural enemies and biopesticides. (edis.ifas.ufl.edu/in849). And there’s a publication out of Canada written by Vineland Research and Innovation Centre that helps growers evaluate the natural enemies they purchase. (bit.ly/biocontrol_products).

GM: What else would you like growers to understand about biocontrol programs?

NL: First, it works. It’s not a myth or something for odd characters. It’s mainstream and it can work for you. In an IPM program, there are times and a place when you need to use a chemical intervention. I’m not opposed to pesticides at all but be aware of their impact on natural enemies.

There are market advantages to using biocontrol including health benefits, no regulatory concerns, and, in the long run, it can be a whole lot easier and less expensive.