We all want worms in our garden soil and vermicompost bins, but how do we go from just a few worms to a booming population? Well, just like every other living creature on Earth, worms need to mate and reproduce. It’s not your typical reproductive process, but it is pretty straightforward. If you’ve ever asked yourself ‘How do worms reproduce?’ then read on for some answers.
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How Do Worms Reproduce?
Like all living creatures, worms need to reproduce to maintain and grow their populations. As older worms die, younger worms need to fill their roles. Without a reproductive process, worm species would die out and become extinct.
The basic principle of all reproduction occurs when an individual male mates with an individual female and fertilizes her egg. The female then either lays her fertilized eggs or gives birth to live young.
Unlike lots of other living creatures though, worms can be hermaphrodites. This means they contain both male and female reproductive organs. This instantly complicates things when we’re trying to answer the question of ‘how do worms reproduce?’.
Because they have both sex organs, they produce eggs and sperm at the same time. They can’t impregnate themselves, but they also don’t always need a partner to reproduce.
When two worms want to mate, they rub against each other as they both secrete mucus to act like a nice warm blanket. They then both discharge a fluid containing their sperm and rub it over each other. The sperm then enters the female part of the worm and is stored safely away. At this point, if each worm has collected the sperm of the other, the worms are both considered fertilized. They pull apart, swap phone numbers, and go their separate ways.
Once the pair have separated and the worms are on their own, each individual will create a small cocoon sack for their eggs.
They will deposit their own eggs into the cocoon, and then insert the sperm they collected earlier from the other worm into the eggs to fertilize them. Once this is done, eggs containing the beginnings of 2-3 worms are deposited into the surrounding soil or substrate, ready to mature and hatch.
Asexual Worm Reproduction
Now for the confusing part.
Some species of worms can reproduce asexually. That is, without a partner. In asexual reproduction, the eggs aren’t fertilized, but are still deposited in the ground and can hatch to create new worms. This process is called parthenogenesis and the offspring are essentially a clone of the parent.
This does happen and can be a quicker way to increase populations, but it doesn’t introduce the genetic diversity that a population needs to stay healthy over time.
Parthenogenesis is a really interesting topic but is heavy on biology and genetics. This article does a pretty good job of explaining it if you’re interested.
How Quickly Do Worms Reproduce?
The fertilized eggs within the cocoon will take around a month to fully develop and hatch. These baby worms then need another month before they’re developed enough to reproduce themselves.
The species of worm and the conditions they’re living in will determine how often worms will reproduce. In ideal situations, reproduction can occur every few weeks. In poor conditions, reproduction can be infrequent, or have a low success rate if eggs fail to hatch.
What Conditions Are Needed For Worms to Reproduce?
If worms are living in a favorable habitat with good bedding and food availability, and with ideal environmental conditions, they are more likely to reproduce more frequently, both sexually and asexually.
If food is scarce, competition for resources is high, or conditions aren’t suited to happy worm life, reproduction will most likely decrease. Worms will generally self-regulate their population within a worm bin for this very reason.
So what are favorable conditions?
According to a study by J.M. Venter & A.J. Reinecke published in the South African Journal of Zoology in 1988, the following conditions are optimal for a particular species of vermiculture worm (Eisenia fetida) to reproduce.
- A constant temperature of 25℃
- A consistent food supply of small particle size organic matter with a moisture content of 75%.
- Relative humidity of 80%.
- Readily available oxygen.
The number of worms you have in your worm bin will also impact reproduction. An ideal density is between 5-10kg of worms per square meter.
So how do worms reproduce?
Worms reproduce like every other creature on Earth, they just do it in a different way to what most people are used to, mainly because they have both sex organs, and all worms are able to get fertilized and lay eggs.
Worms can produce asexually on their own, or sexually with a partner.
When they mate sexually, both worms have their eggs fertilized and place their eggs in cocoons to grow and hatch in the ground.
Worms can produce around 2-3 worms per cocoon and can mate every few weeks if their habitat is at the ideal temperature and humidity, and they have a plentiful food source available.
Since worms will generally self-regulate their populations, there’s no need to worry about your worm bin getting too crowded. If you want to reduce the number you have, then simply remove some worms and place them in your garden.
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