How to Attract Beneficial Insects to Your Garden

developed a number of nontoxic lures to attract
and trap pest insects. Perhaps most familiar are the
Japanese beetle lures and traps. But these arid other pest
lures usually don’t work very well on the small scale of a
home garden because they actually may attract more pests
than initially were present.

There is one lure, developed by Jeff Aldrich, an
entomologist with the U.S. Department of
Agriculture, that attracts one of the
best beneficial insects. Aldrich invites MOTHER
EARTH NEWS readers to help hire test this nifty
homemade Soldier Bug Trap arid Nursery Technique.
— MOTHER.

Spined soldier bugs (Podisus maculiventris) are valuable
beneficial insects in home gardens because they prey on a
multitude of pests, including Mexican bean beetles, cabbage
loopers, diamondback moths, army worms and other
caterpillars, flea beetles and Colorado potato beetles.
When prey is not available, soldier bugs survive by feeding
on plant sap, without significantly harming the plant.

Spined soldier bugs can be found throughout the United
States and Canada. They are more common in the East,
especially around deciduous forests and meadows, which
provide natural prey and cover for the adults to survive
the winter.

Gardeners can learn here how to attract beneficial insects to your garden and enlist the soldier bugs at the right
time to combat garden pests.

The Soldier Bug Nursery has shown promising results for
home gardeners as a pest control technique. The technique
relies on a pheromone (a natural chemical attractant)
produced by male soldier bugs, which we identified and
patented in our research at the U.S. Department of
Agriculture/ Agricultural Research Station’s Insect
Behavior Lab. It is available commercially as the Soldier
Bug Attractor (available from Planet Natural,
www.planetnatural.com). You can use the Attractor
to draw spined soldier bugs to your garden at any time.

With the nursery technique, you can trap the soldier bugs
when they first emerge in spring (before they lay their
eggs), store them in a nursery cage or the refrigerator and
then move them into your garden, where they will lay eggs
and produce hundreds of hungry nymphs.

A System for Trapping Soldier Bugs

Purchase the soldier bug pheromone lure to use in early
spring. In nature, males use their pheromone to attract a
mate, but other males also go to the vicinity of a calling
male in an effort to intercept females. Spined soldier bug
adults are strong fliers and, during responsive phases of
their life cycle, will fly toward the pheromone from
considerable distances.

Generally, soldier bugs are easy to capture. Because they
will walk to the pheromone source, the traps for capturing
soldier bugs must allow easy access while preventing their
exit. The trap described at right takes advantage of the
soldier bugs’ tendency to crawl upward, but not downward.

Trap Timing for Soldier Bugs

Soldier bug adults overwinter under duff, fallen leaves and
the bark of dead trees. Just prior to the bud burst of
deciduous trees (a good indicator is when red maple trees
shed their pollen), the adult bugs come out of their
hibernation (known as diapause ) in a
synchronized, massive emergence. Put your traps out
before they emerge. The bugs soon mate, if they
had not already done so the previous fall, and the females
lay eggs on tree bark and vegetation (about 20 eggs per
cluster; about 300 eggs per female). Eggs hatch in a week
or less depending on temperature. There are five nymphal
stages, each lasting about a week if the nymphs are well
fed, followed by the final molt to the adult stage.

Storing and Using Soldier Bugs in Your Garden

You can transfer the trapped soldier bugs into a nursery area in
your garden. The simplest nursery cage is a cylinder of
aluminum window screen set upright over an area where
insect prey may be present, such as a patch of an
overwintered cover crop or kale. After making the cylinder,
fold the top of the cylinder over and pin it shut with
clothespins. Bank soil around the bottom of the cage so the
adult bugs can’t escape To assure the bugs have enough food
if insect prey is scarce, place some apple slices in the
nursery.

The window-screen cage will hold both adults and nymphs. If
you want to move the nursery every few days to new crops,
rattle the cage a bit: Most of the adult soldier bugs will
fly up and land on the screen. Then you can move the
nursery to a new location.

Make an even more effective nursery by using 1/8 inch
hardware cloth instead of window screen. This material
allows the soldier bug nymphs to escape and move out into
the garden, while the larger adults stay confined and
continue to lay eggs.

You also can keep trapped soldier bugs in the refrigerator
for a few weeks to delay their egg-laying until more garden
crops are up and growing. Every few days, take them out of
the refrigerator for a few hours so they can warm up, drink
and feed. Lightly mist them with water and give them some
apple slices.

Later in the spring you can place the nursery cage right in
the middle of your potato patch, or wherever you need pest
control. Add the bugs you’ve been storing in the
refrigerator: They will lay their eggs and their hungry
little nymphs will protect your crops.

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A Homemade Soldier Bug Trap

• Cut off the top third of a 2-liter soda bottle, and then cut off the screw-cap tip. This is your “funnel.”
• Cut off the top two-thirds of a second soda bottle, leaving the cap on. This is the trap body. Put a few small slits around the top to release the pheromone scent. Cut a wooden stake, about 3 feet long, that will fit through the hole in your funnel, but will allow at least 1/2-inch of clearance so the bugs can crawl in. Hammer the stake into the ground where you want to place the trap. The best sites are along the edges of wooded areas with plenty of brush and leaf litter.
• Slide the funnel over the stake as shown.
• Finally, lay a soldier-bug pheromone lure (not shown in illustration in the image gallery) in the trap’s body. Slide the body onto the stake, and push the funnel section up into the bottom of the body. Tape or staple the bottom edges of the trap.