About Worms

(in much more detail)

 

There are three ecological categories of earthworms, namely anecic, endogeic and epigeic. Compost worms are in the epigeic category.

Anecic (Greek for “out of the earth”) are burrowing worms that come to the surface at night to drag food down into their permanent burrows deep within the mineral layers of the soil. 

Endogeic (Greek for “within the earth”) are also burrowing worms but their burrows are more shallow and they feed on the organic matter already in the soil, so they come to the surface only rarely.

Epigeic (Greek for “upon the earth”) worms live in the surface litter and feed on decaying organic matter. They do not have permanent burrows. These are the type of earthworm commonly called “compost worms”.

The epigeic species of worms have adapted to the highly variable environmental conditions at the soil surface. They have a natural ability to colonise organic wastes, high rates of consumption and digestion, tolerance to a wide range of environmental factors, endurance and high reproduction rates. The species that perform all of these characteristics the best are used for vermicomposting. Of these, the types best suitable for Australian conditions are:

• Eisenia fetida, commonly called“tiger”earthworms because of its striped appearance;
• Eisenia Andrei, commonly called“red”earthworms;
• Eudrilus eugeniae, commonly called the “African night crawler”; and
• Perionyx excavates, commonly called the “blue”

Our worms are a combination of all of these, ie African night crawlers, tigers, reds and blues.

Worms are hermaphrodite, so when they mate with each other both worms produce cocoons. These cocoons are about the size of a grain of rice and contain one to four worms.

 

	Tiger	Red	Blue	African Night
size – width	4 to 8 mm	4 to 8 mm	4 to 5 mm	5 to 7 mm
size – length	50 to 100 mm	50 to 100 mm	45 to 70 mm	80 to 190 mm
temperature limits	0 to 35 C optimum 25 C	0 to 35 C optimum 25 C	25 to 37 C can survive lower temperature but does not grow	16 to 30 C tends not to survive outside this range
cocoons per day	1 every second day	1 every second day	One every day	1 every second day
worms per cocoon	3 or 4	3 or 4	1	2 or 3

 

Different worms do well in different climate

African night crawlers are larger and often used for fishing

 

In extreme temperature conditions, worms will burrow deeper for protection. This works well if your worms are in the garden. If you are using a self-contained worm farm in a warmer climate, leave the bottom tray in for as long as possible, ie until the top tray is completely full. This give worms the best opportunity to protect themselves.

Compost worms can tolerate pH levels from 5 to 9. Contrary to popular belief, they prefer the acidic end of this range, ie closer to 5. So don’t get too heavy handed with “conditioners” such as dolomite that raise the pH level.

Compost worms can also tolerate a wide moisture range from 50% to 90%, but prefer approx. 85%. Worms breathe through their skin, so if it gets too dry they will burrow deeply to find moisture (or die)

Worms are very sensitive to lack of oxygen and salt. They will migrate rapidly in high numbers when these conditions are breached. For example, water logged, or anaerobic condition due to not enough bulk in the bedding. Salt is the worst. If you throw a table spoon of salt into a worm farm, the entire population will exit, even into daylight dry conditions.