The order Odonata is an important group of insects for aquatic ecosystems and has been
frequently used in conservation studies as a bioindicator of priority areas for preservation. In
this context, a survey of the diversity of Odonata species was carried out in 18 streams,
belonging to the Tapajós river basin, located in the Amazon National Park (PARNA), Pará,
Brazil. Using an entomological net in a 150 m transect over a period of one hour, we sampled
adults of Odonata in the 18 streams during the dry season. To estimate species richness, we
used the first order non-parametric Jackknife estimator controlled by sampling effort. To test
sampling efficiency, we used a species accumulation curve, using the Jackkinife estimator with
1,000 randomization. Subsequently, we evaluated the local biodiversity with two ecological
indices: Shannon (H') and Simpson (D)). A total of 301 individuals were collected, with a total
of 40 species. The suborder Zygoptera presented the highest abundance, being 90.4%, in
relation to the 9.6% of the suborder Anisoptera in the sampled igarapés. The estimated species
richness was 55.11 ± 4.4 (mean ± standard deviation), and the collection efficiency was 75.58%.
We recorded a considerable diversity of species (H' = 2.95; D = 0.08). As for the frequency of
occurrence, of the 40 species, 31 were classified as accidental (77.5%), six as accessory (15%)
and three as constant (7.5%). The high integrity characteristics of the Amazon National Park
(PARNA) probably allow a great availability of resources for several species, as observed for
the order Odonata. In detail, we recorded the presence of species with a high level of
ecophysiological requirement, such as Heteragrion bariai, which had the highest abundance,
frequency of occurrence and dominance, and some species of the genera Chalcopteryx and
Mecistogaster, all indicators of preserved environments. Our results demonstrate that PARNA
has an excellent state of conservation, considering that it is home to a high diversity of dragonfly
species. It is extremely important to carry out new surveys of odonatofauna to better understand
species that had low records and also for the monitoring and conservation of the park.
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