Sasha CampbellBraconid wasps are helpful parasitoids. They work well in an organic integrated pest management (IPM) system.
There is an excellent variety of Braconidae (a family of parasitoid wasps) that parasitize specific insect pests. These pests include tomato hornworms, caterpillars, aphids, and beetle larvae.
Below are some of the benefits of encouraging braconid wasps in the garden.
Identification
Firstly, it’s, of course, essential to ensure correct identification.
These predatory wasps are small. They have slim bodies and ant-like heads. Their waists are narrow, and they have long antennae. You might also see a dark spot on the forewing.
The ovipositor of the female is long and black and protrudes from the rear.
At first sight, you might think it’s just another bug. But a closer look shows orange or reddish abdomens. This is quite different from the yellow or black nuisances we see at summer picnics.
Braconid wasps are more likely to be found munching on caterpillars or clouds of aphids.
Life Cycle
Female braconid wasps lay eggs inside the host insect pests. As these parasitic wasps emerge into the larval stage, they begin to feed inside the host [1].
When ready to pupate, the larvae chew their way out of the host pest and make tiny silk cocoons on its exoskeleton. These cocoons resemble fluffy grains of white rice at this time.
Additionally, they are often visible as tiny white clusters that resemble insect eggs along the back and sides of the host insect.
Eventually, the host dies as the wasps break out of their cocoons and emerge as tiny adult wasps. Adult braconid wasps eat pollen and drink nectar, reproduce, and continue the cycle of parasitizing pests.
Benefits to the Garden
The vast variety of Braconidae enables the targeting and parasitization of specific pests. They either live in or on their hosts, from which the larvae feed and weaken.
Braconid wasps are helpful. They control pests like aphids, cabbage worms, and tomato hornworms. These wasps effectively target soft-bodied caterpillars.
Some attack cabbage butterflies; others target wood-boring insects. Adults will attack these creatures. However, their most beneficial purpose is to produce eggs and larvae to weaken or kill garden pests.
How Do Braconid Wasps Kill Their Hosts?
In a season, a braconid female wasp can lay anything from 50 to 200 eggs. Moreover, Aphidius colemani can produce even more eggs inside young aphids.
The wasps may deposit their eggs in the eggs of insect pests.
These pest eggs are unlikely to hatch, and if they do, they will be too weakened to thrive. Other times and/or other types of braconids will deposit their eggs inside pests, where the hatched larvae will feed on them.
The result is the same: the host will eventually die without causing too much damage to crops or reproducing.
Moreover, some Braconidae carry another weapon in their armory: a polydnavirus injected into the host pest [2]. This type of virus has no adverse effects on the host. However, it prevents its immune system from destroying the invading wasps’ offspring.
When the braconid larvae mature into adults, they will create a hole in the cocoons, exit, and initiate the next stage of their life cycle. These natural predators are most prolific in warm, humid conditions during the summer.
Do They Sting?
These beneficial creatures do not sting humans, unlike the hornets and yellowjackets with which we are more familiar. However, they sting their prey to paralyze them for food to grow their offspring.
Habitat
There are about 17,000 recognized species of braconids in the order Hymenoptera [3]. However, many of them are found in North America, Australia, Europe, and other temperate climates.
They live in diverse habitats. You’ll find various species around the world in warm, humid places.
They prefer areas with dense vegetation and easy access to their food source.
This includes forests, wetlands like swamps and marshes, uplands, and meadows. It also covers gardens, crop fields, vineyards, and urban areas.
Other Beneficial Wasps
There are many other types of beneficial wasps, some of which are minuscule.
- Trichogramma is one of the most popular. These natural enemies control soft-bodied caterpillars, such as cabbage worms and cabbage loopers. They also deal with cutworms, armyworms, and corn earworms.
- Eulophids control caterpillars and are usually an iridescent green or blue color.
- Ichneumon wasps are similar but larger than Braconids. They also have a different habit of spinning their cocoons under the skin of the host insect. Their prey includes white grubs, ants, corn earworms, codling moths, and various types of flies.
- Pteromalids are black and are notable for their red eyes. The females mostly parasitize black scale and beetle larvae.
How to Attract Beneficial Predatory Wasps
As with all creatures, wasps need a supply of water. Therefore, a pool or birdbath will help attract these predators.
Additionally, they feed primarily on nectar and pollen. As a result, a flower-filled patch and herb garden will also help attract them and other beneficial insects.
Recommended plants include:
- Sweet alyssum
- Yarrow
- Buckwheat
- Cilantro
- Parsley
- Chamomile
- Catnip
- Dill (which also attracts its prey)
Small florets of flowers, carrot tops, and herbs also provide energy sources for the insects.
Additionally, Umbellifer plants attract them and other beneficial insects, such as ladybugs. These include fennel, sweet cicely, cow parsley, chervil, lovage, and angelica.
Takeaway
The new eco-conscious age is moving back to organic farming and gardening. Braconid wasps play a crucial role in the biological control of pests and are a valuable asset to the garden.
Andre Campbell
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