I am teaching a class about basic vegetable and herb gardening in the fall semester. These are some notes for the students in picture form about insect pests of the garden.
Many insects we call “beneficial” because they prey on pests and keep pest populations under control. Some “beneficials” lay eggs in the larvae of pestiferous flies and aphids, while others eat them directly with chewing mandibles.
Sometimes, it is hard to say exactly if an insect is a friend to humans or if it is detrimental. The relationship varies through time and changes depending on the site. If we were to go to war to try and annihilate an entire group of insects (such as mosquitos for instance) we would likely get pretty sick ourselves and maybe end up losing. So, we try to live with these small but powerful creatures as best as we can.
The cabbage family of plants comprise some of our favorite vegetables. They include the collard greens, broccoli, and kale. I can smell the chick peas, sweet potatoes, and fried chicken already! This family is also the “choys” of Chinese stir fry. The family is distinguished by its four petaled flowers that resemble a cross, hence we also call them the crucifers (from crucifix). Due to their general tastiness and long history of domestication, they are also loved by garden pests.
While weeds make a place look unsightly and not well kept (where is the gardener around here?!), they are also part of a wild web of life on earth that supports a variety of organisms. Weeds hover at the margins of human civilization, and are in a state of constant adaptation. These are three common weeds in San Francisco:
In general, in the garden, pesticides are used as a last resort. They are many ways to prevent outbreaks of insect pests from the beginning, or to keep the pests at a level that is tolerable. Well, what’s a spot or two or a little extra protein?
There are advantages to the use of pesticides too. Well, that will be for another day…Blackberry and ivy are calling me!
Mission Azul 