Many insects live in our gardens. But did you know that most insects are harmless?
In fact, nearly 99 percent of all insects are either harmless or helpful, and just 1 percent are considered pests.
Sometimes we easily recognize beneficial bugs.
Common insects that come to mind include honey bees, butterflies and lady beetles. Other examples of beneficial bugs are predatory wasps, earwigs and big-eyed bugs.
It is easy to encourage beneficial bugs to your garden.
The larra wasp is a fierce predator of mole crickets.
(Courtesy of Andrei Sourakov, Florida Museum of Natural History.)
Start by adding plant diversity. Choose flowers of different colors and shapes, so they attract large and small pollinators.
One highly successful pollinator plant is scorpion’s tail. This plant has tiny white flowers that are attractive to wasps and flies.
Another great choice is partridge pea. The partridge pea has light green leaves and bright yellow flowers. Partridge pea blooms throughout the year. Not only does it serve as a host plant for yellow sulphur butterflies, it also serves as a nectar plant for butterflies, bees and pollinators. Planting partridge pea in your garden will ensure visits by our native pollinators.
When encouraging beneficial bugs to your garden, properly identify “pests.” When you see an insect or a bug, take the time to identify it before taking action.
My favorite bug is the mealybug destroyer. Most people find this bug in its larval form. As larva, it resembles a giant, white mealybug with a bad hair day. But, this bug seeks out and eats pest insects such as scales and mealybugs. At first glance, a reaction may be to squish or spray it. However, when left alone, the mealybug destroyer moves quickly and eats its prey. Eventually, it turns into a black lady beetle.
The mealybug destroyer is a type of lady beetle, and inadvertently killing it significantly decreases the ability of a key insect to assist you with your garden’s pest control.
(Courtesy of Jack Kelly Clark, University of California)
Some beneficial bugs have been introduced as biological control agents. These insects typically link with a key pest, plant or problem.
For example, the air potato vine is an invasive exotic plant that grows rapidly, has few known natural predators and propagates easily by tubers. Air potato vine had few predators, until now. The air potato leaf beetle was released a few years ago, primarily in natural areas such as state parks. This reddish orange beetle has successfully lived in the wild, reproduced and is voraciously eating the air potato vine leaves. When this beneficial bug eats the air potato vine leaf, it effectively reduces the leaves’ ability to make food through photosynthesis. Over time, this beetle will help reduce the amount of land covered by the invasive vine.
There are other great biological controls, such as the larra wasp.
Most people do not realize that wasps and flies can be beneficial. In particular, the larra wasp is a predator of mole crickets.
Mole crickets are insects that love bahiagrass.
Mole crickets are large, active at night, and they form burrows in soil — called galleries —that damages grass roots.
The larra wasp loves mole crickets. It finds a mole cricket, drags it up to the soil surface, and lays an egg on the soft underside of the mole cricket. When the mole cricket travels back, down into its tunnel, the larra wasp egg eventually hatches and the larra wasp larva consumes and kills the mole cricket.
The larra wasp is a great beneficial bug. You can attract it by planting larraflower Spermacoce verticillata. The tiny clusters of white flowers are very attractive to larra wasps and other pollinators.
Lastly, be careful with pesticide use. Use the least toxic or soft pesticides, such as insecticidal soap and horticultural oil, whenever possible. Rotate vegetables to keep vegetable garden pests guessing. Choose pest-resistant varieties and follow the first principle of Florida Friendly LandscapingTM: right plant, right place. By selecting the right plant and planting it in the right location, you may be able to reduce pest and disease problems.
So, don’t forget: Most insects are harmless or are actually helpful, and just 1 percent of insects are pests.
Also, recognize that proper identification is important, and that in cases like the mealybug destroyer, larva can look very different from the adult form of that same insect.
If you need help identifying an insect, contact your local Extension office.
By Nicole Pinson
Nicole Pinson is an Urban Horticulture Agent in Hillsborough County.
Published October 21, 2015
