If you see a wasp flying around your garden it’s probably looking for something to eat. But what will that tasty treat be? Are any destructive garden pests on the wasp’s menu?
Well, it turns out that…
Predatory wasps eat many types of garden pests, such as flies and aphids. Other wasps, called parasitoid wasps, lay eggs on or in host pests such as moths and beetles. When the wasp larvae hatch, they eat and kill the host pest. All wasps help to keep insect populations under control and protect plants from being destroyed by insects.
Even though there are over a hundred thousand wasp species around the world, all wasps are either solitary or social. In fact, how they live has a big influence on what a wasp eats and how dangerous they are.
According to National Geographic, most wasps are solitary insects – living alone – and cannot sting. The ‘stinger’ that you see at the end of their abdomen is called an ovipositor. This is what the females use to lay eggs or drill through things like bark.
On the other hand, social wasps live in groups called colonies. A colony of wasps live together in a nest and raise young wasps together. Social wasps are usually able to sting, and they often come in bright colors as a warning to other predators that if the wasp gets attacked, it will defend itself with its stinger.
Without wasps, the world could be overrun with spiders and insects. Each summer, social wasps in the UK capture an estimated 14 million kilogrammes [15432 US tons] of insect prey … Perhaps we should be calling them a gardener’s friend.
Source: Natural History Museum
What do wasps eat?
Nearly all young wasps (called larvae) eat meat in the form of insects. But as they grow up, their diet may change or expand.
Most adult wasps live on sugars and carbohydrates to give them energy to work and fly. But adult wasps may eat one or more of these things:
- Aphids
- Live insects
- Spiders
- Other wasps
- Insect eggs
- Dead insects
- Honeydew from aphids
- Nectar from flowers
- Lerp from psyllid bugs
- Wasp larvae saliva (more on this later)
- Ripe fruits
- Raw meat
- Human foods
Baby wasps eat insects
Nearly all parasitoid wasps are solitary wasps that live alone and eat insects or spiders when they are young.
Before laying her eggs, solitary female wasps will find an insect or bring an insect to her nest to become a host for her young. The wasp lays her eggs on or inside the body of the insect host. When the eggs hatch, they feed on the host.
Source: Sturgis McKeever, Georgia Southern University, Bugwood.org
Social wasps live and work together to care for the larvae. Adult wasps from the colony go out in hunt for food – a tasty grasshopper, mosquito, or fly will do just fine. The wasps usually break these insects into parts and bring the insect pieces back to the nest as larvae food.
Though adult wasps spend a lot of time looking for insects to feed their young, some will take the opportunity to suck the body fluids out of insects when they want to.
Adult wasps eat sugars and carbohydrates
An adult wasp’s diet consists mainly of nectar, honeydew, and larvae saliva.
Plants release the sugary substance called nectar, mostly in their flowers, to attract insects such as wasps.
When a wasp comes to eat and collect the nectar in a flower, it may also collect pollen on its body and spread the pollen to other flowers of the same species or even on the same flower. This is the process of pollination, and it is how plants reproduce.
Besides nectar, wasps also love eating honeydew, a sugary liquid released by the garden pest aphids.
Social adult wasps in a colony have another food source: the abundant sugary saliva that wasp larvae make.
According to researchers, wasp larvae saliva is full of sugars and amino acids – exactly what the adult wasps need to give them enough energy to fly 62 miles (100 km) per day looking for meaty insects to feed the larvae.
Wasps will also eat human foods
As many insects and flowers die off toward the end of Summer, social wasps struggle to find meat to bring back to the colony and nectar to eat. Because the larvae are eating less meat, they produce less saliva.
Food can become very scarce for the colony around this time of year.
So, wasps need to look elsewhere for food, and they often start with ripe fruits on the ground, the waste in garbage bins, or the sweet desserts and fruit juices at your picnic table.
This is why you might notice more wasps around this time of year.
What garden pests do wasps eat?
Wasps help to keep insect populations under control because insects are an important part of a wasp’s diet and lifecycle.
Some pests and insects that adult wasps hunt and feed to their young are:
- Ants
- Aphids
- Bees
- Beetles
- Boll weevils
- Butterflies
- Cabbage loopers
- Cabbageworms
- Caterpillars
- Cicadas
- Cockroaches
- Colorado potato beetles
- Corn earworms
- Crickets
- Cutworms
- Flies
- Grasshoppers
- Japanese beetles
- June bugs
- Katydids (click here to find out if katydids are actually garden pests)
- Leafhoppers
- Locusts
- Millipedes
- Mosquitoes
- Moths
- Slugs
- Snails
- Spiders
- Wasps
- Western corn rootworms
- Whiteflies that love feeding on tomato plants
- White grubs
Are wasps garden pests?
Social wasps can become pests when their populations get out of control or they nest close to buildings. These wasps may sting people when they feel threatened – their sting is painful but is only dangerous for people that are allergic to wasps. But wasps are not considered garden pests and help keep pests under control, including each other.
Wasps are mostly beneficial insects as they eat many common garden pests and can help to pollinate the plants and trees in your garden.
In fact, experts report that wasps are some of the biggest pollinators of fig trees, pollinating more than 800 kinds of figs, over 100 species of orchids, mango trees, and sesame plants.
A wasp colony moving in could make you uncomfortable, and you might want it removed by a professional. But if the nest isn’t in a high traffic area and you want to take advantage of the natural eco-friendly pest control offered by wasps during the Spring and Summer months, it’s a good idea to leave the nest alone or even plant more plants that will attract wasps.
Check out this video from BBC Ideas on why wasps are so important in the ecosystem and why we should welcome them in our gardens (or at least not harm them):
What plants attract wasps?
If you want to attract beneficial wasps to your garden choose plants and trees that:
- Have colorful blue, white, or yellow flowers without any red (wasps don’t like red)
- Have open, single flowers that are easy to access
- Bloom between July and September
- Are woody and provide protection
- Grow sweet fruits
- Make plenty of nectar
Wasps particularly like Queen Anne’s Lace (a wildflower herb), Yarrow, Winterberry Holly, Goldenrods, Asters, and Forsythia.
Fruit trees and sweet fruit crops are popular with wasps, especially watermelons, fig trees, and mango trees.
Flowers that wasps aren’t interested in and that may even keep them out of your garden include plants and grasses like:
- Citronella
- Eucalyptus
- Evening Primrose
- Ferns
- Geraniums
- Jasmine
- Marigolds (click here to find out how marigolds repel garden pests)
- Mint
- Pennyroyals
- Wormwood
3 common wasps and what they eat
Wasps can be identified by their lower pointed abdomen and narrow midsection that separates the abdomen from the chest or thorax. A wasp’s body tends to be smoother than a bee’s, with only fine hair on it. This smoothness makes it easier for the wasp to catch its prey.
There are three common wasps found in the United States:
Paper wasps
Source: Jerrod Hein, Kansas State University, Bugwood.org
Paper wasps are the wasps that you are most likely to find nesting outside your home or by your shed. They’re called paper wasps because their nests are made out of a paper-type material – strips of bark.
To build a nest, paper wasps chew pieces of bark and spit out a wet type of paper. They use this paper to build their nest in a cool dark place.
These social wasps have long legs and long, slender waists. Many have yellow and black bands around their body, or they can be black or reddish-brown in color.
As social wasps, the adults eat nectar and larvae saliva. But they do catch pests in your garden to feed to their larvae in the nest.
These wasps are not very aggressive and their stings are less toxic than other wasps.
Yellowjackets
Source: Whitney Cranshaw, Colorado State University, Bugwood.org
Yellowjackets are social wasps that have black and yellow or white stripes. Their bodies are similar in shape to paper wasps.
These wasps build their nests underground, in wall cavities, and hanging from structures.
You’ll know you’re looking at a yellowjacket if it flies in a quick side-to-side pattern before it lands.
Adult yellowjackets eat nectar from flowers, fruits, and tree sap. They are the scavengers of the wasp world and spend a lot of time hunting for insects, meat, dead fish, animal hides, and fruit. The wasps chew these meat sources and then feed it to young wasps in the colony.
In return, the larvae make sugary saliva to feed the adult workers.
Bald-faced hornets
Source: David Cappaert, Bugwood.org
Bald-faced hornets are social wasps that live in a colony. The adults are omnivores and eat both meats and plants, and they aren’t very picky eaters.
Adult bald-faced hornets are known to eat many garden pests, such as caterpillars, flies and spiders. They are also happy to eat tree sap, fruits, raw meat, and nectar.
Bald-faced hornet larvae live on protein from insects and spiders.
These wasps are quite aggressive and will sting someone many times for walking too close to their nest and making them feel threatened.
