Agriculture Reference
In-Depth Information
where native species still exist, there is still very considerable potential for discovery of new species.
Any new species reported in the
native genera
bimastos and isenoides or even from a new genus. Additional new species might also be expected
to occur in other nearctic genera, such as arctiostrotus, diplocardia, and komarekiona.
lumbricidae will most probably come from the two
E
L
H
ARTHWORM
IFE
ISTORIES
It is amazing that, of the nearly 8000 oligochaete species described (Reynolds and Cook 1993),
ecological and life history studies have been made on relatively few species, probably fewer than
20. Lee (1992) suggested that only about six lumbricid and six tropical species have been studied
in sufficient detail to provide adequate life history information. However, Barois et al. (1999)
provided basic ecological and life history data on 58 tropical earthworm species, but not all
described in detail. Some of the information gathered on the ecology of common
lumbricidae was
obtained from a time when species lumping occurred; that is, descriptions were attributed to
Allolobophora caliginosa,
which now includes several species, so further studies may be needed
for clarification.
M
E
T
ODERN
ARTHWORM
ECHNIQUES
One technique that has been considered for years, but only recently had any evidence to support
its potential in taxonomy, is electrophoresis. Using this technique, B¾gh (1992) illustrated that
certain earthworm species were different (i.e.,
Aporrectodea tuberculata
and
Aporrectodea turgida
were distinct species), and he demonstrated how to identify species from fragments. There is also
considerable scope for use of DNA analyses in taxonomy (see
Chapter 3
, this volume).
U
SE
OF
E
ARTHWORMS
FOR
W
ASTE
M
ANAGEMENT
The acceptance of organic waste recycling and vermicomposting using earthworms has gained
increasing acceptance over the past 2 decades and is increasing rapidly in both industrialized and
nonindustrialized countries (see
Chapter 18
, this volume). In North America, the research is
restricted to only a few species (
), but with
almost 4000 megadrile species available, the search should be for additional species that may be
harnessed to assist the decomposition and transformation of waste products into useful materials
Eisenia foetida
,
Eudrilus eugeniae
,
Perionyx excavatus
(see
Chapters 18
,
19
, and
20
this volume).
E
E
M
ARTHWORMS
FOR
NVIRONMENTAL
ONITORING
The ability of many species of earthworms to accumulate heavy metals and various pesticides into
their tissues offers opportunities to trace the movement of these materials in the
soil. One aquatic
microdrile species
, Tubifex tubifex
, has been used for decades as a biological indicator in polluted
waters.
is used in a standardized terrestrial assay using artificial soil to assess the
toxicity of pesticides and other chemicals (Edwards and Bohlen 1992).
Research is needed on the toxicities uptake mechanisms, distribution, and concentration of
chemicals in various types of earthworm tissues. In particular, interpretation of the findings on
chemicals and earthworms as they relate to our daily lives is needed.
Eisenia andrei
P
L
L
E
LAIN
ANGUAGE
AND
ESS
SOTERY
I have long advocated the necessity for scientific information to be more accessible to the general
nonscientific community. Entomologists and ornithologists have advanced more rapidly because
of the joint contributions of ÑamateursÒ and general collectors. In the early part of this century,
earthworm biology had one such person, the Hilderic Friend, who was turned aside and dismissed
