BackSwimmer: All You Need to Know in a Nutshell

Backswimmers are fascinating aquatic insects known for their unique swimming style and intriguing characteristics.

These slender, oval, streamlined water bugs have a distinct appearance with keeled backs, resembling the bottom of a boat, and long, oar-like hind legs that have fine hairs, which they use for propulsion.

Interestingly, they swim with their ventral side (belly) facing upwards, hence their common name of backswimmers.

Their swimming technique often seems peculiar, as they move in a belly-up orientation while navigating through water.

A notable feature of backswimmers is their ability to rest at the water surface with their abdomen tip protruding from the water in a tilted head-downward position.

Backswimmers are piercer-predators that feed on a variety of prey, including tiny fish fry, tadpoles, and invertebrates.

When comparing backswimmers to other aquatic insects, such as water boatmen, one significant difference is their method of capturing food.

While backswimmers have piercing beaks to suck bodily fluids from their prey, water boatmen lack this feature and instead ingest living material like diatoms as they swim along the bottom of a pond.

Both backswimmers and water boatmen play essential roles in the aquatic ecosystem and provide an engaging subject for nature enthusiasts to observe and study.

Overview of Backswimmers

Backswimmers are a family of aquatic insects belonging to the order Hemiptera and the family Notonectidae. They are commonly known as “true bugs” because they are a part of the “true bug” category.

These creatures have a unique size, usually ranging between 0.5 to 1 inch in length.

They have an interesting manner of swimming, gliding through the water belly-up using their long, oar-like hind legs. Their colors often include shades of gray, yellow, green, or tan.

Living underwater, Backswimmers exhibit some unique characteristics:

• Streamlined, oval-shaped body
• The back is keeled, resembling the bottom of a boat
• Equipped with fine hairs on their legs for efficient swimming
• Resting on the water surface tilted head-downward

Comparing the Backswimmer with a similar aquatic insect, the Water Boatman:

Habitat and Distribution

Backswimmers are aquatic insects found in various water bodies. They inhabit ponds, lakes, and even swimming pools.

These insects are commonly found with other aquatic life. They share habitats with: Amphibians and Invertebrates

Backswimmers have a wide distribution. They are native to places like the UK and Mexico

In different regions, they adapt to changing seasons. In winter months, backswimmers may display a brown coloration, blending in with their surroundings.

Physical Characteristics and Adaptations

Body Structure

Backswimmers have a slender, oval, streamlined body adapted for swimming.

They have a keeled back, similar to the bottom of a boat¹, with a silvery appearance due to air bubbles trapped on their body surface².

Hind Legs

These insects have long, oar-like hind legs¹. The legs have fine hairs which help with swimming¹. The powerful hind legs allow for fast movement in the water, especially when chasing prey.

Mouthparts

Backswimmers are piercer-predators². They have a sharp beak adapted for piercing and sucking the bodily fluids of their prey, such as:

• Small invertebrates
• Fish fry
• Tadpoles²

Their beak can also inject venom, which can paralyze their prey².

Eyes

These bugs have reddish eyes³ that enable them to detect prey and avoid predators in the water environment.

Wings

Backswimmers can fly, but they are clumsy fliers. However, they are attracted to lights so then can fly near lights in the evenings.

Scuba Tank-like Air Reservoir

Backswimmers have a unique adaptation in which they carry an air bubble attached to their abdomen tip¹.

This air reservoir allows them to stay submerged for extended periods, hunting for prey and avoiding predators¹.

Comparison: Backswimmers vs Water Boatmen

Behavior and Life Cycle

Feeding Habits

Backswimmers are piercer-predators that feed on various invertebrates and vertebrates, including tiny fish fry and tadpoles.

They swim head down along the bottom in search of food, using their piercing beak to suck out their prey’s bodily fluids ¹.

Mating and Reproduction

During spring and summer, backswimmers mate and lay eggs on vegetation near the water surface.

They can produce multiple generations in a single season, with nymphs developing into adults throughout the warm months.

Predation and Defense Strategies

Backswimmers are agile swimmers and can escape predators by diving deep into the water.

They also have a unique defense strategy: releasing a foul-smelling substance when threatened.

Metamorphosis

The development of backswimmers includes:

• Eggs
• Nymphs (larvae)
• Adults

As the nymphs grow, they undergo metamorphosis, shedding their exoskeleton several times before becoming adults.

Hibernation

In colder regions, backswimmers hibernate during winter months by burrowing into the mud at the bottom of water bodies.

They emerge in spring and resume their activities.

Interactions with Humans and Other Species

In the Food Chain

Backswimmers belong to the family Notonectidae in the order Hemiptera and play a role as predators in the food chain. They feed mainly on:

• Insects
• Tadpoles
• Small fish
• Crayfish

These water bugs use their piercing beak to inject toxic saliva into their prey before consuming the bodily fluids¹.

Backswimmers as a Garden Presence

Backswimmers, also called water wasps or water bees, can be found in various water bodies like:

• Ditches
• Canals
• Wildlife-friendly ponds

Creating a wildlife-friendly pond in your garden can help attract these insects. They are known to share their habitat with other aquatic species like:

• Water striders
• Diving beetles
• Nymphs

Dealing with Backswimmers in Swimming Pools

In case backswimmers invade your swimming pool, you can employ these methods:

• Careful manual removal
• Avoid using chemicals, as they may harm other species

Painful Bites and their Treatment

Backswimmers can deliver a painful bite, often compared to a bee sting⁴. Here’s what you can do in case of a bite:

1. Clean the bite area with soap and water.
2. Apply a cold pack to reduce pain and swelling.

Conclusion

In summary, Backswimmers are insects that belong to the family Notonectidae. They have oval-shaped bodies, long legs, and prominent eyes.

They are found in freshwater habitats around the world, where they swim upside down near the surface. They feed on other aquatic animals, such as insects, tadpoles, and small fish.

They are both predators and prey in the aquatic food chain.

Backswimmers are unique and fascinating creatures that demonstrate the diversity and adaptation of life in water.

Footnotes

1. Missouri Department of Conservation ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸
2. UWM Field Station ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹
3. MDC Teacher Portal ↩
4. Backswimmers Water Bees; Water Wasps | MDC Teacher Portal ↩