Agriculture Reference
In-Depth Information
use in vermicomposting, it should possess certain specific biological and ecological characteristics,
that is, an ability to colonize organic wastes naturally; high rates of organic matter consumption,
digestion, and assimilation; ability to tolerate a wide range of environmental factors; high repro-
ductive rates by producing large numbers of cocoons, which should not have a long hatching time,
and growth and maturation rates from hatchlings to adult individuals should be rapid; and they
should be strong, resistant and survive handling. Not too many species of earthworms possess all
these characteristics.
T
S
EMPERATE
PECIES
Eisenia fetida
(Savigny, 1826) and
Eisenia andrei (
Bouché, 1972)
The closely related
species are the ones most commonly used for the
management of organic wastes by vermicomposting. There are several reasons why these two
species are preferred: They are peregrine and ubiquitous with a worldwide distribution, and many
organic wastes become naturally colonized by them; they have good temperature tolerance and can
live in organic wastes with a range of moisture contents. They are resilient earthworms and can be
handled readily; in mixed cultures with other species, they usually become dominant, so that even
when systems begin with other species, they often end up with dominant
E. fetida
and
E. andrei
Eisenia
spp
.
The biology
and ecology of
, when fed on animal manures or sewage sludge, have been
investigated by several authors (Graff 1953, 1974; Watanabe and Tsukamoto 1976; Hartenstein et
al. 1979; Kaplan et al. 1980; Edwards 1988; Reinecke and Viljoen 1990; Elvira et al. 1996a;
Domnguez and Edwards 1997; Domnguez et al. 1997; Domnguez et al. 2000).
Under optimal conditions, their life cycles, from freshly deposited cocoon through sexually
mature clitellate earthworm and the deposition of the next generation of cocoons, range from 45
to 51 days. The time for hatchlings to reach sexual maturity ranges from 21 to 30 days. Copulation
in these species, which takes place in the organic matter, has been described by various authors
since 1845 and has been observed more often than for any other megadrile species. Cocoon laying
begins 48 hours after copulation, and the rate of cocoon production is between 0.35 and 1.3 per
day. The hatching viability is 72 to 82%, and the incubation period ranges from 18 to 26 days. The
number of young earthworms hatching from each viable cocoon varies from 2.5 to 3.8 depending
on temperature. Maximum life expectancy is 4.5 to 5 years, but the average life survival was 594
days at 28
E. fetida
and
E. andrei
C, although under natural conditions it may be considerably less
than these figures because they have so many predators and parasites in the wild (Edwards and
Bohlen 1996).
A
C and 589 days at 18
A
Dendrobaena rubida
(Savigny, 1826)
Dendrobaena rubida
is a temperate species of earthworm with a clear preference for organic soils,
and it inhabits substrates such as decaying rooting wood and straw, pine litter, compost, and peat
and is found near sewage tanks and animal manures. Although some aspects of their biology have
been investigated (Evans and Guild 1948; Gates 1972; Sims and Gerard 1985; Bengtsson et al.
1986; Cluzeau and Fayolle 1989; Elvira et al. 1996b), this species is not widely used in vermicom-
posting systems.
can complete its life cycle in 75 days, and its rapid maturation
and high reproductive rate could make it a suitable species for vermicomposting. Compared with
other vermicomposting species,
Dendrobaena rubida
grows relatively slowly, although it reaches sexual
maturity relatively quickly (54 days after hatching). Cluzeau and Fayolle (1989) reported that it
was sexually mature after 44
D. rubida
E
10 days. We found that the net reproductive rate for
D. rubida
was
2.06 hatchlings per mature earthworm
week
(Elvira et al. 1996b), although cocoon production
−
1
−
1
rates by
D. rubida
reported in the literature of 3.22 cocoons week
(Cluzeau and Fayolle 1989)
−
1
are usually higher than those we reported (2.31 cocoons week
; Bengtsson et al. 1986). Gates
(1972) reported that only one earthworm emerged from 75% of the cocoons of
−
1
D. rubida
, with 2
