Wasps are part of the Hymenoptera order, which contains the primary pollinators of the world, including bees. Though wasps are not often recognized as beneficial, they play a key role in pollination as well as in the control of harmful or invasive insects.
Most wasp species are either solitary or parasitic, but there are also at least 850 social wasp species that live in colonies and create hives. Compared to bees, wasps are less efficient at pollinating, but they are still able to pollinate and feed off of nectar as bees do.
How Do Wasps Pollinate?
Most wasps pollinate in a way similar to bees, except bees carry a greater amount of pollen. Pollen sticks to bees’ hairy bodies, which they may transfer to a pollen basket on their hindlegs. Wasps lack this ability, the difference makes wasps less effective at pollinating.
Despite this, wasps are important because they may visit and pollinate flowers that bees do not reach.
Wasps have slick abdomens with sparse hair, unlike their hairy bee cousins. Pollen sticks to the small amount of hair that wasps have on their bodies and legs, which is then pollinated, but to a lesser extent than bees.
However, some studies have shown that in some circumstances, wasps can be more efficient than bees. Also, there are specific pollinating roles of wasps, such as pollinating orchids and figs.
There are some wasps called pollen wasps, of which there are about 300 species, and these are more bee-like in their behaviour. They are vegetarian and solely feed off of pollen and nectar. These wasps take pollen in through their mouths and store it internally, rather than in a basket on the legs as bees do.
What Do Wasps Eat?
Wasps are omnivores and eat other insects, invertebrates, and nectar. Wasps prey on other insects to give to their larvae. Adult wasps only eat sugars, though. Wasps get hydration and sugar from drinking the nectar from flowers or fruits. As they drink the nectar from flowers, they passively transfer pollen between flowers. The parasitic forms of wasps lay their eggs on or in other insects or invertebrates, and they become the hosts.
Some species will prey on or scavenge for dead animals and nectar is just a small part of their diet. With other species, like pollen wasps, they feed off of nectar and pollen and are not carnivorous.
Which Plants Are Dependent on the Wasp Population?
There are two ways wasps help plants and crops: they pollinate or they prey on insects and invertebrates that destroy plants. All over the world, countless insect pests are controlled by having a wasp predator that either kills them to feed the larvae or uses them as a host for their offspring.
In many agricultural settings, wasps are used to protect crops from infestation. The one stipulation here is that wasps will feed on diverse insects, so they can also hunt the beneficial insects – not just the pests.
What Plants Do Wasps Pollinate?
Wasps are generally accidental pollinators, so while they are looking for nectar from flowers, they get pollen on their small hairs and spread it from one flower to the next.
The flowers that tend to lure in wasps are dull, odorous, and have nectar that is easy to access. Most wasps have short mouths, so they cannot get nectar from flowers where it is too deep. Wasps will pollinate garden flowers, crops, and fruit trees.
One flower that needs wasps for pollination is the orchid. There are 100 types of orchids that require wasp pollination. Orchids have adapted visual cues and specific scents that smell like female wasps, so male wasps will come and attempt to mate, which in effect allows for pollination of the orchid.
Fig wasps are another example of a specific role wasps play. Figs are entirely dependent on fig wasps for pollination. Fig wasps pollinate numerous types of fig plants.
The fig contains its flower in the inside of the fruit, and it gets pollinated by a specific process. This works by the fig plant producing a scent that attracts female fig wasps, and the wasp enters through a small hole. Within the fruit, she lays her eggs while pollinating many fig flowers. Then, after laying eggs, the female wasp dies. These eggs become future fig wasps, which leave the fig when mature.
Pollen wasps are another major group that contributes to pollination. Additionally, wasps are the primary pollinators for an orchid called broad-leaved helleborine. This orchid emits similar pheromones as caterpillars, which is why wasps are attracted to the flowers.
What Pests Do Wasps Protect Plants From?
Essentially, every pest has a wasp to hunt it, so it is difficult to describe the scope of wasps’ ability to protect from harmful species. One example is the hornworm, which is a victim of parasitic wasps. Wasps will lay their eggs inside hornworms, which makes the hornworm a host. The hatching wasp eggs then kill hornworms. This pest control saves many tomato plants from destruction.
Additionally, wasps will eat caterpillars, which damage plants, flowers, and crops. In Minnesota, wasps were used beneficially. Parasitoid tree wasps were released in an effort to control the emerald ash borer by targeting the insect larvae or eggs.
Pollen Wasps
Pollen wasps rely on nectar and pollen for food and do not scavenge or prey on other animals. This vegetarian preference is similar to that of bees and leads them to pollinate more than other wasps.
These wasps take pollen and nectar into their mouths, rather than on their exterior like other wasps. Then, the wasps use the pollen and nectar as food for themselves and their larvae, unlike other wasps that use insects as food for the larvae.
Pollen wasps prefer flowers of the waterleaf family, which are located in North America. Pollen and fig wasps can sometimes be more effective pollinators than bees in certain areas.
Bee vs. Wasp Pollination
Bees are greater contributors to pollination because the majority of their species are vegetarian. They also have lots of hair to store and transport pollen, whereas wasps have sparse hairs and smoother bodies. Bees also have baskets for pollen on their legs, which can transport a lot of pollen at one time. Pollen wasps have a storage mechanism similar to this that is internal, but most wasps do not.
Only a few wasp species feed off of a primary plant diet, while most others are omnivores. Wasps that are general feeders are passive pollinators and happen to transfer pollen as they search for nectar.
Studies have shown some instances where wasp pollination is more effective than bee pollination, and they also play a key role in reaching plants that bees cannot access. Finally, they are important pollinators of orchids and figs.
Wasps Are Important Pollinators
Wasps are misconstrued as an inconvenient species. However, many crops and plants in our ecosystem rely on them for survival. Their contribution allows us to harvest and grow food, either by direct or indirect pollination or by insect control.
Similar to bees, wasps pollinate by transferring pollen between flowers as they feed. Predatory wasps also feed off of harmful insects for their larvae and use them as hosts for their eggs. Eliminating these insects aids in keeping plants healthy, which works favourably towards a balanced ecosystem.
Wasps often are underrecognized insects, but their importance is key for pollination, control of pests, and the overall health of our crops and a diverse array of flowers and plants.
