Agriculture Reference
In-Depth Information
The first attempt to present a regional review of the earthworm distributions in continental
North America was in the 1970s (Reynolds 1975a, 1976b). During the past 20 years, there have
been many advances and additional available data for many regions (states and provinces) in North
America. The first summary of regional earthworm surveys in North America was made (Reynolds
et al. 1974). Since that time, there have been wide-ranging earthworm collections in North America,
resulting in many publications on the distribution of various species of earthworms in North America
and Mexico (Fragoso et al. 1994). An updated version of that table appeared in 1994 and 1995
Other Countries
There has been considerable expansion of knowledge of megadrile earthworm distributions on other
continents as well. For instance, de Mischis (1992, 1993) expanded the distributional records for
Argentina. The first survey of the earthworms of Swaziland appeared (Reynolds 1993). This survey
reported seven species from that small African country. Earthworm surveys undertaken during 1992
and 1993 contributed to the first survey of the earthworms of Bangladesh (Reynolds 1994d), where
14 species were reported, and there were speculations on the possible presence of an additional 28
species. The first survey and report of earthworms from Belize indicated three species:
Dichogaster
bolaui
(Reynolds and Righi 1994).
Additional earthworm samples were obtained subsequently (Reynolds and Guerra 1994). Two
additional examples of original surveys were in San Andres and Contadora Island (Reynolds and
Reynolds 2002a,b) and Gough Island, South Atlantic Ocean (Reynolds et al. 2002).
,
Pontoscolex corethrurus
, and a new species,
Eodrilus jenniferae
D
IVERSITY
There have been considerable data published on earthworm diversity in the Americas. The current
status of various aspects of earthworm research on this continent has been summarized (Fragoso
et al. 1994; Fender 1995; Hendrix 1995; James 1995; Reynolds 1995).
B¾gh (1992) published an interesting and innovative article, ÑIdentification of Earthworms
(Lumbricidae): Choice of Method and Distinction Criteria.Ò In this article, he discussed the use of
electrophoretic techniques in the identification of earthworm species. One of the immediate benefits
of this approach is the potentially more accurate determination of juveniles and fragments of the
caliginosa
complex that the late Dr. Gordon Gates and I have long advocated. The morphological
criteria developed by Gates (1972a) that were used in many of my surveys throughout North
America were supported by B¾gh (1992).
I (1994a) prepared a summary in
. This included discussions of global
distributions, barriers to migration, habitat requirements, and functions of earthworms in the soil.
Earthworms of the World
T
AXONOMY
For a field of science as limited as oligochaetology, it is fortunate there are topics that combine all
the description citations and type depositions of earthworms: the
Nomenclatura Oligochaetologica
and its three supplements (Reynolds and Cook 1976, 1981, 1989, 1993). The third supplement
(
), which recorded new taxa found up to December 31, 1992, suggested that
739 earthworm genera, 40 subgenera, and 7254 species have been described. A fourth supplement
(Reynolds and Wetzel 2004a) described more than 1048 new species. Some of the most exciting
discoveries regard the presence of nearctic species in the far reaches of North America, areas where
they were not previously recorded. These include FenderÔs (1985) and McNab and McKey-FenderÔs
(1947) work on
Supplementum Tertium
in the northwestern United States and southwestern
British Columbia (Canada) as well as JamesÔs (1995) discoveries of
Bimastos
and
Arctiostrotus
Argilophilus
and
Diplocardia
in the southwestern United States.
