“Will earthworm farms thrive well in a tropical environment?” ~ Taiwo Tope
Worm farms can indeed thrive in a tropical environment, but there are some important considerations to keep in mind before you begin. On the positive side, the tropics offer much warmer conditions than many other parts of the world, thus making it possible to keep your farm active all year long.
Where you are specifically located may have significant implications – not all tropical locations are created equal!
In some countries/regions severe seasonal weather fluctuations may have a negative impact on your operation (especially if it is situated in an unprotected outdoor location). Obviously if you live in an area that experiences seasonal hurricanes or monsoon conditions, you’ll need to take some steps to ensure your worms are protected.
Excess water in your worm beds may lead your worm population to start venturing elsewhere. I’ve read accounts of Blue Worms (Perionyx excavatus) – a composting worm commonly used in the tropics – making mass migrations in heavy rains traveling great distances, and even sometimes ending up in bizarre places like trees and building rooftops!
Aside from potential weather issues, you also may want to learn more about the native wildlife in your region. One of the most devastating earthworm predators is the land flatworm (also known as planarians). These creatures can apparently wipe out an entire worm population in a very short period of time due to their rapid reproduction (in addition to breeding via sexual reproduction, they can also do so via fragmentation) and voracious appetite.
Generally, these worms (which aren’t actually worms – i.e. they are not related to earthworms in any way) are only a major threat in warmer regions, although there are cooler-climate species as well. As such, you may want to get in touch with someone at a local university or government agriculture office to see if they are known to occur in your region.
As mentioned above, Perionyx excavatus is often used for vermicomposting/vermiculture in tropical regions. Another commonly use species in warmer climates is Eudrilus eugeniae (African Nightcrawler). It has demonstrated excellent waste-processing ability (and reproduction) when its needs are met.
Interestingly enough, Eisenia fetida (Red Worm) – which is likely the most commonly used composting worm in the world – has actually been shown to be superior to P. excavatus and E. eugeniae in terms of overall performance, even in hot climates.
Reinecke et al (1992) compared the three species and found that E. fetida had a much higher and lower temperature tolerance than the other two.
That being said, it is not a bad idea to work with worms found naturally in your area. I’d recommend searching in piles of aged animal manure and/or other organic waste refuse heaps to see if you can find a species suited for vermicomposting. A sure sign you’ve found a good candidate is the presence of a large number of individuals in a small area, and the presence of these dense populations in above-ground materials (i.e. you are not looking for soil-dwelling worms).
Using local worms (if possible) can save you the hassle of trying to track down one of the species mentioned above, and also has the added advantage of providing you with a worm that is well adapted for conditions in your region.
Hope this helps!