| The Tropical
Andes has been designated a global biodiversity hotspot, defined as a
region harboring exceptional concentrations of endemic species but at
the same time experiencing exceptional loss of habitat. The region is
increasingly threatened by deforestation, construction of hydroelectric
dams, oil drilling, mining, hunting, fishing, and other human activities.
In response to these threats, a network of protected areas has been established
to conserve the most important remaining intact Tropical Andean ecosystems.
Within Bolivia several protected areas including Alto Madidi, Pilón
Lajas, and Apolobamba (collectively known as Madidi), have been established
as part of an international conservation corridor extending from Vilcabamba
(in Peru) to Amboró (in Bolivia). This area is biologically unique
because it acts as a transition zone between the drier highlands and the
more humid lowlands, creating an interface where species from both ecosystems
may occur. Yet, the majority of species-level biodiversity remains unexplored
and this impedes research and conservation management efforts in the area.
Critically understudied in the region are caddisflies, or Trichoptera.
Caddisflies are slender, elongate, moth-like insects. Their aquatic larvae
are of considerable ecological importance and they are commonly used as
biological indicators of water quality.
Previous collections in Bolivia:
Considering the size of the country, the Bolivian fauna has received relatively
limited attention. As a result, very little is known about the Trichoptera
of Bolivia and there have been just a handful of collections in the region.
Of the over 2,000 species known from the Neotropics, Dr. O.S. Flint, Jr.,
Smithsonian Institution, has described an amazing 903 (41% of the fauna),
yet surprisingly only 5 of those species were based on material from Bolivia
(Flint et al. 1999). Although Dr. Flint has traveled and collected Trichoptera
extensively throughout the Neotropics, he has never visited Bolivia. Similarly,
other notable taxonomists of the fauna, R.P.L. Navás and F. Schmid,
based their work on incidental collections by individuals not targeting
Trichoptera. The majority of Bolivian Trichoptera currently found in museums
was collected either by the Chilean, L.E. Peña, who visited the
Yungas region in 1984, or by Jesuit missionaries working near Cochabamba
in the 1920s and 30s. More recently, Spector and colleagues (American
Museum of Natural History) collected Trichoptera as part of a broader
entomological survey of Parque Nacional Amboró in 2001.
Estimation of species diversity in Bolivia:
The order Trichoptera contains about 11,000 described species worldwide,
but as many as 50,000 may occur, especially in the unexplored tropics.
As of 1999, there were just over 2,160 species known from the Neotropics.
However, no census of regional caddisfly diversity for the Neotropics
has been available until Holzenthal's inventories of Costa Rica and southeastern
Brazil. From Holzenthal’s survey of Costa Rica, 463 species are
known to date. The original number of species recorded in the literature
from the country prior to the survey was about 100. During the survey
an additional 102 previously described species were collected (or twice
the number recorded in the literature), representing new country records.
The remaining 261 species (56% of the total) were new species that have
been or will be described by Holzenthal and his colleagues. Similarly,
in southeastern Brazil, only 176 species were known from the literature
prior to survey. Now, 610 species are known from SE Brazil including an
additional 154 previously described species and 370 new species (61% of
the total). The real diversity of both regions, including species that
remain uncollected and additional microcaddisflies likely to be added
from incomplete taxonomic investigations on the material, is undoubtedly
higher.
Currently, only 60 species of caddisflies have been recorded in the literature
from the entire country of Bolivia (1,098,581 km2 or 22 times the size
of Costa Rica). Comparing this to the number of species known from Costa
Rica (463), one can see how relatively tiny that number is. Indeed, our
preliminary surveys in Bolivia have suggested that the true caddisfly
species diversity is significantly higher. Preliminary results from only
2 collections (July 2003 & Nov-Dec. 2004) have yielded over 48 species
new to science and more than doubled the number of species previously
known from the country. Still, these collections served only as a snapshot
of the Bolivian caddisfly fauna. Further collections are needed to better
document this region’s incredible caddisfly fauna.
Biogeography:
Due to its geographic location,
Bolivia is uniquely positioned and may sit at the crossroads of the northern
Andean, Amazonian, Chilean, and southeastern Brazilian faunas. It should
be stressed that for many Bolivian taxa our current knowledge of species
diversity is so inadequate that it is almost impossible to make even the
most speculative statements about distributional patterns and faunal relationships.
The faunas of southern Chile and Argentina are fairly well known and the
faunas of southeastern Brazil, Central America, and other parts of the
Neotropics are becoming better known. By stark contrast, the Trichoptera
fauna of Bolivia is almost wholly unknown. Furthermore, the phylogenetic
relationships among the Trichoptera species in all these areas remain
largely unresolved. A major objective of our inventory is to establish
a firm taxonomic base and knowledge of the Bolivian fauna so that phylogenetic
and historical biogeographic studies of the entire austral caddisfly fauna
can proceed.
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