Biological control, or biocontrol, is an increasingly popular approach to controlling greenhouse pests. Using beneficial pathogens, predators and parasitoids/parasites provides an alternative to conventional chemical control and can serve as an effective component to a comprehensive integrated pest management (IPM) program.
There's no doubt that there is excitement surrounding biocontrol right now. But for some, this approach to pest control can be intimidating. Specifically, the two broad reasons why biocontrol is perceived as being a challenge to implement are: knowledge and economics.
This article is going to break down why these perceptions may exist and provide some insight into how to approach them.
Learning the relationship between pests and the biocontrols that can be used to control them is the backbone of any biocontrol program.
The first essential step is to correctly identify your target pest(s). A good hand lens or simple microscope and online or printed identification resources, combined with a little time and practice, will help overcome this first hurdle.
Once the pest has been positively identified, the next steps are to determine: 1) which predators, parasites or parasitoids; and 2) which pest life cycle should be targeted for control. There are numerous resources that biocontrol suppliers have developed that can help guide which biocontrols are effective at controlling your pest(s), as well as recommended life cycles to target for release.
Developing a routine, regular monitoring program in the greenhouse is going to have several benefits, including: 1) the early detection, identification and regular monitoring of pests populations and their life cycle stages; 2) monitoring biocontrol populations; and 3) subsequently determining the effectiveness of pest control measures. Regularly monitoring sticky cards (and changing them!), foliage and root systems throughout the greenhouse and recording the findings will make managing a biocontrol program much more successful.
All or … nothing?
Another perception that gets growers nervous when considering biocontrols is they think it means they can't use pesticides anymore.
While eliminating pesticide applications may be the goal for some biocontrol users, biocontrols can also be a part of a well-developed IPM strategy that also includes chemical control. When looking to integrate biological and chemical control, it's important to understand the compatibility of different biocontrol agents and pesticides so chemical applications do not negatively affect biocontrols and reduce their efficacy or kill them.
One of the best ways to overcome the knowledge barrier in biocontrol programs is to have a person who can be dedicated to it and can serve as its “champion.” By dedicated, I am not suggesting that managing biocontrols be the only aspect of their job; rather that managing biocontrols be assigned to them and those responsibilities not distributed across a number of individuals. This can make it easier for someone to build up the necessary skillset to implement and manage a biocontrol program, and as competency increases over time, so will the efficiency. Although “many hands make light work”, this approach may not result in anybody vested in the program enough to ensure its success at the beginning.
Once the person leading a new biocontrol program in the greenhouse has built up their knowledge and skills, they can start to educate others and increase their participation.
What’s the price tag?
The cost of biological control programs is the other primary concern for those considering initiating one. It can be difficult to broadly characterize the cost of any biocontrol program, as it will depend on the target pest(s), followed by subsequent comparisons of the costs of the chosen chemical(s) used to control pests and the biocontrol(s) chosen to replace chemical control.
It's a little easier to compare the costs of the approach to biological control releases in a greenhouse, though. An inundative approach to biocontrol is somewhat akin to a pesticide application, where the release of biocontrols is expected to reduce pest populations immediately and there is not much expectation or concern about the biocontrol reproduction and establishing populations.
Alternatively, inoculative biocontrol releases are intended to establish populations that will reproduce within the greenhouse. Although inundative releases are more straightforward (i.e. release reactively when pests are a problem), inoculative releases will not only help control pests before they become problematic and cause damage, they will also reduce input costs since biocontrol reproduction will reduce or eliminate the need to continually purchase beneficial insects and/or mites.
The effectiveness of your biocontrol program directly affects its cost, where a less effective program will cost less, while a more effective program will cost more. The effectiveness of your program will be linked to some of the knowledge barriers already discussed, and by sticking with a biocontrol program and investing the time to monitor the success of your program and investing the time to improve it, costs should decrease as you become more effective.
However, there are some other, less-tangible cost savings or added value that can be associated with a biological pest control program that may offset some of the expenses associated with implementing one.
Right now, we are experiencing a labor shortage, from hourly employees up to salaried head growers. Other industries that historically may not have paid competitive wages are becoming more aggressive with what they offer. Job satisfaction can play an important role in employee retention and recruitment. The idea of suiting up in personal protective equipment to apply pesticides is not something most people look forward to, and biocontrol releases (and the monitoring of them) offer a stark contrast as an employee experience.
Outside of the production space and in retail areas, can your biocontrol program help you market your crops to customers? With the “greening” of retail products, biocontrol is something that can be a positive differentiator for your crops.
Biological control is only going to continue to increase in popularity and importance in greenhouse crop production of food and flower crops. There is no doubt it is a departure from traditional chemical pest control techniques. So don’t let the prospect of change intimidate you. Instead, try to view it as an opportunity that you can take advantage of now to realize the numerous benefits it offers.