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15 Differences: Water Bug vs Cockroach

A typical US household is more likely to be infested with a cockroach, like a palmetto bug than a water bug. Although they may look similar but differentiating them is pretty easy because of a vast number of differences.

Interestingly, both are part of Insecta but are grouped differently (Cockroaches under order Blattodea whereas water bug Hemiptera).

Water bugs are outdoor species with larger and flatter bodies than cockroaches; they have two legs and much shorter antennas sitting under the eyes. Unlike roaches which are dark brown, they have a greyish color and yellow strips behind the head. Water bugs love to live near water bodies and prey on other aquatic animals.

Water bug is also known as Giant Water Bug, Electric Light Bug, and Giant Fishkiller.

I have elaborated 17 differences between roach and waterbug, including their origin, size & color, habitat, feeding habits, and ways of reproduction. Moreover, cockroaches can differ from water bugs in their lifespan, flying capabilities, infestation, and spreading diseases.

Although cockroaches rarely bite whereas water bugs, if disturbed, can sometimes bite in self-defense. The bite can be painful but is devoid of any severe consequences. After going through the blog below, I am convinced you will easily differentiate between water bugs and cockroaches.

Before you read further, just a quick question. Tired of cockroaches and looking for a permanent solution?

Stop wasting your time, invest in these products and follow this guide: How to get rid of roaches? You will be roach-free in 10-20 days.

1. Max Force Glue Traps
2. Advion Gel Baits
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4. Gentrol Insect Growth Regulator
5. Loctite Foam Sealent

Optional Items
1. Gel Bait Professional Gun
2. Torch
3. Powder Bait Puffer
4. Insecticide Spray to kill a reveled colony in a single shot

1. Origin of Water Bug vs Roach

Although the origin of American cockroaches aka palmetto bugs can be traced back to tropical climates of Africa, Floridians named them palmetto bugs due to their close association with palm trees.

On the other hand, water bugs are thought to be originated from the black and Caspian sea (some biologists associate them with Russia and Africa).

Origin difference between Water Bug vs Palmetto Bug

2. Size and Color of Water Bug vs Cockroach

There is a marked variation in size and color among different types of cockroaches. Adult bugs can range from 28mm up to 53mm. The color also varies from light to smokey and dark brown.

In contrast, water bugs are more flatter, with large sizes ranging from 50mm to 100mm. The color of the water bug is more tilted towards a greyish hue. Moreover, a strip of yellow markings usually covers the area behind the head.

Water bugs have antennas smaller than their heads than roaches, including palmetto bugs, which is a prominent differentiating feature.

Size difference between Water Bug vs Palmetto Bug

4. Habitat of Water Bug vs Roach

American cockroaches and water bugs both love to live outdoors. Whereas both can infest homes, water bugs will very rarely do so. Cockroaches love warm and humid environments and are usually located inside bathrooms, garbage, basements, and food storage cabinets.

However, german roaches can severely infest homes as they love living indoors.

On the other hand, as the name suggests, water bugs are located near water bodies like lakes, ponds, and streams. Thanks to their air storage capabilities, they can survive under the water for many hours.

Habitat difference between Water Bug vs Palmetto Bug

5. What does Water Bug Eat?

Cockroaches, including palmetto bugs, are omnivorous and feed on leaves in the outdoors. Inside the home, they live on leftovers, including garbage, fruits, and pieces of bread. Besides these, palmetto bugs love to eat starchy foods, mainly bakery items.

On the other hand, water bugs are quite picky and usually prey on fishes, amphibians, and aquatic insects. They release a powerful enzyme that has the capability to paralyze the prey.

Feeding difference between Water Bug vs Palmetto Bug

6. Reproduction Cycle of Water Bug vs Cockroaches

Reproduction is the cornerstone for the survival of species. Cockroaches prefer to reproduce in the late humid summer season. An adult female American cockroach lays eggs 55 days after mating. The baby palmetto bugs undergo molting to transform into eggs.

It is pretty interesting to know that male and female water bugs actively participate in reproduction. Once the female bug finds an appropriate male partner, she mates and lays eggs on the wing of the male bug after 55 days. The male then takes care of eggs and periodically visits water to prevent the eggs from drying out.

The eggs hatch after 45 days and the larva is born. The larva undergoes five staged metamorphoses before it is transformed into an adult water bug.

Eggs & Reproduction of Water Bugs vs Palmetto Bugs

7. Life Span of a Water Bug vs roaches

Interestingly, male American cockroaches have a shorter life span than female bugs by up to 3 months. The life cycle of cockroaches is, on average, two years. This can vary between different environments and places. The life span of a palmetto bug is also dependent on the availability of food and water. You can read more on how long does a palmetto bug lives? Here.

Although adult water bug has a similar life span to cockroach, the overall life span from eggs to death is shorter by up to 6 months. This is because the nymphal stage in water bugs is shorter, with only 4 to 5 molts taking almost 2 to 3 months to transform into adult bugs.

Life span of Water Bugs vs Palmetto Bugs

8. How do water bug Communicate?

When it comes to communication, cockroaches have a complex organized method of communicating with each other. This is achieved through a variety of chemical odors called pheromones. The composition of these pheromones changes according to the message. They can pass information about food, danger, and mating.

The water bugs communicate with their colony through water ripples known as ripple communication. The verticle oscillation of legs creates a cascade of waves that another member picks up. The water bug can transmit a set of messages, including food, mating danger, and territorial guarding (Source).

Inter communication of Water Bugs vs Palmetto Bugs

9. Roach vs water bug flight

Cockroaches don’t fly regularly, and when they do, they mostly glide for a short distance. Some cockroaches are heavy enough that they are intrinsically designed to crawl. Cockroaches fly in case of imminent threat and only when the conditions are ideal. Likewise, not all palmetto bugs fly; only adult Smokybrown and American Cockroach can fly. The Florida Wood cockroach doesn’t have wings, and it can’t fly. Please read more on ” Can a Palmetto Bug Fly? ” here.

Water bugs, on the other hand, are good flyers. They have two sets of wings, one larger and darker than the other. They usually fly during the late humid summer months, when it’s ideal for mating. The water bug flies from one water body to another. They can fly 30 to 50 meters in one go. Like other insects, water bugs are attracted to bright lights, and you can occasionally see them flying toward the light sources.

Flying capabilities of Water Bugs vs Palmetto Bugs

10. Defense mechanism of water bug vs palmetto bug

When it comes to defense mechanisms, cockroaches have a very unique and sophisticated system. The defense mechanism is adopted to serve two functions

1. To act as an emergency escape system from a threat, and
2. To serve as a signaling mechanism, informing the colony about an imminent threat.

Florida cockroach species of Palmetto bug spray a foul-smelling liquid on the prey, which acts as an irritant and a signal. It is essential to know that palmetto bugs have a limited juice supply; it takes three months to refill it.

On the other hand, when they feel threatened, water bugs can play dead or even bite. The bite is a powerful defense mechanism that paralyzes the prey or elicits a painful response to predators, including humans. Plus, they can also emit unpleasant odors from their anus, which wards off predators.

11. Image of Water Bug Eggs vs Roach Eggs

American cockroaches produce eggs 55 days after mating and hatches after 45 days. The eggs are encased in a light brown sac called ootheca. Interestingly, ootheca is visible to the naked human eye and measures a few millimeters. Each egg sac contains between 13 to 15 individual eggs. Learn more about roach eggs ere.

Female Water bug lays eggs in batches of 100 plus eggs. The eggs are creamy colored and resemble the seeds of the sunflower. Some water bugs lay them on the green vegetation while others on the back of the male partner. The selection of place depends on the species of water bugs. It just takes two weeks for the eggs to hatch.

Eggs of Water Bugs vs Palmetto Bugs

12. Water Bug Babies vs Roach Babies

Cockroaches can multiply quickly. An adult female American roach keeps on producing an ootheca (Containing approx 15 individual eggs) every month for the rest of life. At the end of her life, she will have given rise to approximately 120 to 180 offspring. Since cockroaches live in hidings, their survival rate is high.

On the other side, an adult female water bug will produce between 150 to 400 eggs in her lifetime. The number of eggs produced depends upon the optimal conditions and environmental temperatures. An adult female water bug can give rise to between 100 to 300 offspring in her life.

In one study, the highest number of eggs (420) was produced at 24 degrees Celcius (Source). The eggs on the back of the male partner are most likely to hatch with a 97% probability.

The survival rate of water bug babies is low due to their diet or being prayed by other animals.

Population growth of Water Bugs vs Palmetto Bugs

13. Water bug Bite vs roach bite

Cockroaches, like other roaches, scavenge on rotting food and leaves. They are almost innocent when it comes to biting humans. This does not mean that they are not able to bite. They can and do bite sometimes when disturbed. The bite is trivial, primarily with very few cases of severe pain. You can read more on Do Cockroaches Bite? Here.

Likewise, Water bugs are scavengers and are known to bite. They also can bite humans, but only when they feel threatened. They bite with the help of proboscis and mouthpiece, injecting a powerful enzyme that has the capability to liquefy host tissue and paralyzes their prey. Their bite is mostly not dangerous to humans but can sometimes cause pain and severe allergic reaction, requiring medical consultation.

14. Health Risk

Cockroaches are known to transmit diseases. An infested cockroach can transfer enteric fever (Salmonella Typhi and Para Typhyi) from feces to food or kitchen surface. They are also known to elicit allergic asthmatic attacks in atopic people. The cause for allergic reaction is mainly the pieces of exoskeleton molt. Learn more about: Are Cockroaches Dangerous?

Water bugs are known as toe biters. Their saliva is usually non-toxic to humans, but their bite can cause immense pain or sometimes even cause a complete or partial loss of sensation of the bitten area (hypoesthesia). Although it is usually thought that water bugs do not transmit any disease, a recent study in West Africa Concluded that they might be the cause of Buruli Ulcer (Caused by Mycobacterium Ulcerans whose incidence is increasing steadily) (Source).

Diseases spread by Water Bugs vs Palmetto Bugs

15. How to get rid of water bugs?

Although recent advances in chemical pesticides have proven disastrous for roaches, eliminating roaches can pose some serious challenges. Boric acid, chemical sprays, and bait traps all are proven to be lethal to cockroaches. You can also use natural cockroach repellents if you want to ward them off without squashing them to death.

Likewise, chemical pesticides, boric acid, and detergents can be used to kill water bugs effectively. I personally prefer using boric acid to kill water bugs because it not only kills water bugs but also stays on the surface for a long.

How to kill a Water Bugs vs Palmetto Bugs

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