Growing Plants to Attract Insect Predators
FOR IMMEDIATE RELEASE
May 23, 2013
URBANA – As gardeners trend toward more natural ways to grow
small fruits and vegetables, both in the backyard and at community garden plots
where traditional control products may not be allowed, insect predators can be
of use, said University of Illinois Extension horticulture educator Richard
"There are a number of predator insects that can help us
control the destructive ones," said Hentschel. "The commonly known ones include
several versions of the lady beetle. Both the adults and larvae feed on aphids.
Ground beetles also feed on both adults and larvae of destructive insects such
as root maggots, snails, slugs, caterpillars, and weed seeds.
"Other lesser known predators are pirate bugs, damsel bug
nymphs, and assassin bugs," he added. "These three feed on soft bodied insects
that damage our plants. Lacewing larvae feed mainly on aphids mainly whereas
the adults also use nectar and pollen as food besides feeding on aphids."
Another group of predators, not officially an insect, but an
insect relative, includes spiders. All spiders do not necessarily build a
typical web, Hentschel said. Those are the orb weavers, catching their prey in
the web itself.
Other spiders include wolf spiders, preying on insects that
move along the ground. Also included are jumping spiders, who get their name by
how they attack their prey. These spiders stalk and then pounce on prey.
Crab spiders will usually sit quietly waiting for prey to walk by and then
reach out with their strong legs and make the capture. They can walk sideways
and resemble crabs in that way, Hentschel explained.
"Spiders can be found throughout the backyard and in
undisturbed areas," he said. "They do not necessarily need a favored plant but
a favorable environment."
According to Hentschel, another insect that is often
referred to, but is not as helpful, is the praying mantis. "This is a very
interesting insect to watch, yet is not one of the better predators for the
Although predator insects, such as the lady beetle, can be
purchased by mail order or at a good garden center, Hentschel said the
challenge is keeping them in the yard as they are mobile, and will distribute
themselves around the yards nearby.
"In order to attract and keep these predator insects in
and around the garden, there are a couple of conditions that need to be met or
maintained," Hentschel explained. "Without a food source of destructive
insects, the good guys will go elsewhere. Without a small population of their
prey on your desirable plants and vegetables, there will not be a population of
predator insects when you really need them.
"The other condition is a need for host plants that
attract the predators into your yard. These can be cultivated flowers or more
native plants. Coneflower and coreopsis are native and have interesting
flowers. Cup plant and yarrow also are attractive and native. Some less
ornamental plants could be wild carrot and parsnip. These two and those already
noted are perennials. Anytime you have plants that self-sow, managing the
plantings is really needed so you do not end up with the proverbial weed patch
that can be a problem in the neighborhood or for immediate property owners."
Hentschel added that there are many more plants that can
be used, depending on where the home is located. Homes in more rural
settings and with larger yards have more choices, he said.
"You can find plants in the carrot, aster, mustard, and
legume families that could be considered ornamentals and natives," he said. "If
you are going to establish insect predator-friendly plantings, remember that
you will need to take care of those plants just like you do for other plantings
until they are established."
Source: Richard Hentschel, Extension Educator, Horticulture, firstname.lastname@example.org