The Battle Against Fruit Tree Pests

Part of what we would like to do with this blog is to share great information from around the web – especially some of the more esoteric content that may make the average tree lover go cross-eyed. We would like to not only point you to some of these cool resources, but also give you some analysis and context, which may allow you to enjoy these educational gems more than you normally would. 

To that end, we posted an analysis and synopsis of a wonderful lecture on the characteristics of fruit tree roots, by David Eissenstat, a few weeks ago. 

Today, we are going to review another lecture from the University of Wisconsin YouTube playlist. This one comes courtesy of Jay Brunner, a professor of entomology with Washington State University, and is entitled, “The Evolution of Tree Fruit Pest Management Practices.??? Given the establishment of the Asian citrus psyllid in California, and the presence of many other pests throughout the country, it seems like an apropos topic. 

This particular talk (embedded below this post) is only about 30 minutes, so you can get through it a little quicker than Eissenstat’s hour-plus lecture.  The talk largely revolves around Brunner’s work with apple tree pests in Washington. It is quite an interesting video from beginning to end, but three points really stood out:

History of Integrated Pest Management

Brunner begins by reviewing the history of pest management strategies (we just reviewed these principles a few days ago, so be sure to go back and give this a quick read if you are not clear about what “integrated pest management??? is all about).

He explains that pest management strategies exist along a continuum. Strategies that rely on synthetic compounds, considered the “conventional??? approach, lie at one end of the spectrum, while “organic??? strategies lie at the other end. Integrated pest management sits smack dab in the middle, as it borrows from both ends of the spectrum. 

The Power of Pheromones

Pheromones -- chemicals used in social contexts by various species (in this case, arthropods) – are often very effective in some forms of pest control. Although pheromones function in a variety of ways, many of those used in pest control applications are those used by females to attract males. In other words, you can use female pheromones to lure males into a trap of some variety. As the male population drops, females have fewer mates, and the species’ population declines. 

Pheromones have a few important advantages of synthetic pesticides, which make them very popular among those who embrace integrated pest management strategies. First of all, the use of pheromone traps does not require you to broadcast potentially harmful chemicals throughout the habitat. Instead, they rely on the reproductive drive of the pests and simple traps to reduce the overall impact of the pest. 

Secondarily, pheromones do not lead to resistance. They may lead to evolutionary changes in the pheromones produced by the insects or their behavioral patterns, but this is an easier nut to crack than resistance. In the video, Brunner explains that pheromones are not only useful in killing pests; they are useful for monitoring local pest populations as well.  

The Importance of Models

Brunner emphasized the importance of models in reaching pest-prevention and mitigation goals. The primary way in which models are helpful is through their predictive abilities. Sound, well-tested models can predict the development of insect pests (or disease), which has important ramifications for monitoring and control. 

Consider, for example, that you are a farmer who needs to apply a pesticide when the marauding insects are in a particular phase of their lifecycle. If you apply the pesticide too early or too late, it will be ineffective and your harvest will suffer. However, if you use a model to inform your scheduling decisions, you are all but assured of greater success. In the video, Brunner details the accuracy of their models, which accurately predicted the date of hatching of a common apple-tree pest, in more than half of the years in their study (the model was correct within two days for the entirety of the testing period). 

Thanks again for visiting; we hope you are finding these types of posts helpful. Talk to us in the comments and let us know what types of topics you would like to learn more about. Of course, Bay Area residents battling fruit tree pests can just give us a call. One of our ISA-certified arborists will examine your trees and recommend a prudent course of action. Just remember that prompt action is imperative for saving trees and avoiding emergency tree removal. San Francisco, Millbrae and Larkspur residents should make the call (415-310-7781) to Arborist Now today! 

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