Abstract:
The diversity of geometrid moths (Lepidoptera:
Geometridae) was investigated in two tropical montane
cloud forests in southern Ecuador and in central Costa
Rica. The study covered an elevational range from c.
1000 to 2700 m.a.s.l. in both locations. Data were
analyzed for eight sites, representing four elevations in
each of the two study areas. A total of 770 species (4569
specimens) were sampled in Ecuador vs. 503 in Costa
Rica (7303 specimens). Sampling was incomplete and it
is expected that more species will be found in both areas.
Moth diversity was extremely high in Ecuador and
almost invariably higher than at comparable elevations
in Costa Rica. Values of Fisher?s a index ranged between
70 and 131 in Ecuador, and between 31 and 83 in Costa
Rica. An analysis of rarefied species numbers led to very
similar results. At a level of 390 rarefied specimens, the
range was 131?179 species at the Ecuadorian sites, vs.
77?140 at the Costa Rican sites. Only 64 (5.3%) out of the
total of 1209 species were common to both areas. The
results of this study underline the fact that the tropical
Andean mountains are one of the ?hot spots? of local
diversity of geometrid moths, and that the threatened
Andean cloud forests should be given the highest priority
in conservation policy. Similarly, countries like Costa
Rica, which are already actively engaged in nature
conservation, may find additional motivation in the
present results to continue their efforts.
