In general, perennial flowers bloom during a relatively short, specific time period, while annuals tend to bloom for much of the summer or until a heavy frost kills the plant. The time of bloom, as well as the flower size and structure itself, may influence which natural enemies visit a plant.
There are a variety of natural enemies you might find on your flowers. Common flower visitors include syrphid or hover fly adults that often resemble tiny bees and hover over the flowers. (The larvae or maggots are good aphid predators.) Green lacewing adults, minute pirate bugs, lady beetle adults and larvae, and ambush bugs are other predators that can be seen on flowers. Parasitic wasps in various sizes and shapes are other frequent flower visitors. On the larger wasps you may be able to see the long ovipositor ("stinger") that the female uses to place her eggs inside the host. Unlike yellow jackets or honeybees whose ovipositor is modified for defense purposes and can sting people, a parasitic wasp can't use its ovipositor to sting people. You may see some of the stinging wasps, such as the paper wasps, at flowers. Count them among your natural enemies, too, since many capture caterpillars or other insects to feed to their young. Which types do you see most frequently and on which types of flowers? Do the types you see vary at different times of the year? Do you ever see these natural enemies or their offspring at work in your garden or yard eating or parasitizing pests?
- Susan Mahr, University of Wisconsin - Madison
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