Corresponding author: Gizelle Amora (
Academic editor: Fabio L. Da Silva
In most freshwater ecosystems, aquatic insects are dominant in terms of diversity; however, there is a disproportionately low number of records of alien species when compared to other freshwater organisms. The
Amora G, Hamada N, Fusari LM, Andrade-Souza V (2015) An Asiatic Chironomid in Brazil: morphology, DNA barcode and bionomics. ZooKeys 514: 129–144. doi:
Alien species represent one of the most serious threats to biodiversity at different taxonomic levels (
Despite their dominance in terms of diversity in most freshwater ecosystems, aquatic insects have a disproportionately low number of alien species when compared to other freshwater macroinvertebrates (
Among the necessary characteristics for a species to become a successful invasive alien are: phenotypic plasticity, ability for uniparental reproduction and fast growth in disturbed habitats (
During a study on aquatic insects in Amazonas state (Brazil), we collected specimens of
In view of this complex situation, our objectives were to register a
Egg masses of the
Larvae were fed fish food (TETRAMIM®) every 48 hours. The colony established using this collected material was kept in the insect-raising facility at the Coordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia (INPA), at environmental conditions similar to those of the climate in Manaus during the months from May to September 2011: temperature of 26 ± 0.3 °C; air humidity of 75 ± 7.7% and photoperiod of 12/12 hours (data obtained from
Emerged adults with pupal and larval exuviae from the colony were dissected and mounted on slides with Euparal® following the procedures outlined by
Molecular analyses were done using the DNeasy Blood & Tissue (Qiagen) kit following the manufacturer’s recommendations. Amplifications of the extracted DNA from three specimens (2 larvae and 1 adult male) of the Brazilian
Sequences for 14
Voucher specimens of the Brazilian population are deposited in the Coleção de Invertebrados do Instituto Nacional de Pesquisas da Amazônia. Haplotype sequences are deposited in GenBank under the accession numbers
GenBank and BOLD accession numbers of the sequences from species of
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*GenBank; **BOLD; - data unpublished.
The egg masses were characterized by their shape, length, width and number of eggs; the maximum length and width of eggs were measured. In order to determine the development time of the egg stage, five egg masses were isolated and observed every hour until first instar hatched.
Ten egg masses were isolated to determine the development time of each of the four larval instars; starting from the moment at which the first instar hatched, three larvae were fixed (in 80% ethanol) daily, until the last larva of the egg mass pupated. To identify the instar of each of the fixed larvae; they were mounted between slide and coverslip (using Hoyer as the mounting medium) to measure the ventral length of the head capsule, following the methodology of
To estimate pupal development time, 50 pupae were observed every 12 hours from the moment of pupation until adult emergence. Longevity of adults was estimated using 50 adults that emerged in the laboratory on the same day; these were isolated in pairs (male and female) in cages made of PET bottles and observed until there were no more survivors.
The morphology of the Brazilian
Adult male and pupae.
In the neighbor-joining tree (Fig.
NJ tree based on the COI sequences of the mtDNA of
Genetic distance between Groups A and B and other
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | ||
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1. | Group A |
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2. | Group B | 9.6 |
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17.0 | 15.6 | |||||||||||
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17.2 | 19.5 | 12.0 | ||||||||||
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14.4 | 13.3 | 13.5 | 17.9 | |||||||||
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13.3 | 13.6 | 15.4 | 16.7 | 15.0 | ||||||||
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17.2 | 17.0 | 11.0 | 5.5 | 16.3 | 17.4 | |||||||
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16.5 | 17.5 | 10.5 | 3.1 | 16.8 | 17.2 | 4.0 | ||||||
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18.2 | 17.2 | 12.0 | 8.8 | 16.1 | 16.5 | 8.4 | 8.2 | |||||
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17.9 | 15.7 | 15.4 | 18.7 | 15.1 | 18.3 | 16.4 | 17.0 | 18.4 | ||||
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14.8 | 16.1 | 16.1 | 17.2 | 12.1 | 15.5 | 17.2 | 16.2 | 16.3 | 17.0 |
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13.7 | 12.2 | 14.3 | 15.7 | 11.7 | 13.8 | 15.6 | 15.0 | 16.6 | 16.6 | 12.3 |
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16.9 | 15.6 | 16.1 | 18.6 | 16.2 | 15.3 | 17.0 | 17.6 | 19.6 | 15.7 | 17.5 | 15.7 | |
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10.5 | 10.6 | 10.1 | 5.9 | 13.8 | 9.4 | 7.4 | 6.7 | 6.5 | 12.3 | 9.7 | 10.5 | 13.8 |
Pairwise per cent nucleotide differences (p-distance) between all specimens based on the COI gene in the mtDNA. Analyses were conducted using the Kimura-2-parameter model. Values in bold are genetic distances between Groups A and B.
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | ||
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1. | ||||||||||||||||||||
2. | 0.0 | |||||||||||||||||||
3. | 0.0 | 0.0 | ||||||||||||||||||
4. | 0.8 | 0.8 | 0.8 | |||||||||||||||||
5. | 0.8 | 0.8 | 0.8 | 0.0 | ||||||||||||||||
6. | 0.8 | 0.8 | 0.8 | 0.0 | 0.0 | |||||||||||||||
7. | 0.8 | 0.8 | 0.8 | 0.0 | 0.0 | 0.0 | ||||||||||||||
8. | 1.1 | 1.1 | 1.1 | 0.3 | 0.3 | 0.3 | 0.3 | |||||||||||||
9. | 1.2 | 1.2 | 1.2 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | ||||||||||||
10. | 1.7 | 1.7 | 1.7 | 0.9 | 0.9 | 0.9 | 0.9 | 1.2 | 1.5 | |||||||||||
11. | 0.9 | 0.9 | 0.9 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.5 | 1.1 | ||||||||||
12. | 0.9 | 0.9 | 0.9 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 1.2 | 0.2 | |||||||||
13. | 0.9 | 0.9 | 0.9 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.5 | 1.1 | 0.0 | 0.2 | ||||||||
14. | 3.0 | 3.0 | 3.0 | 2.5 | 2.5 | 2.5 | 2.5 | 2.8 | 3.1 | 3.3 | 2.6 | 2.8 | 2.6 | |||||||
15. | 2.8 | 2.8 | 2.8 | 2.6 | 2.6 | 2.6 | 2.6 | 2.6 | 2.9 | 3.3 | 2.4 | 2.6 | 2.4 | 1.3 | ||||||
16. | 2.8 | 2.8 | 2.8 | 2.2 | 2.2 | 2.2 | 2.2 | 2.2 | 1.9 | 3.1 | 2.0 | 1.9 | 2.0 | 3.3 | 2.8 | |||||
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18. |
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0.6 | |||
19. |
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0.6 | 0.6 | ||
20. |
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1.9 | 2.2 | 2.0 |
Within Group A there are three specimens of
Egg masses of the Brazilian
The four instars of the Brazilian
Frequency of occurrence of the ventral length of the cephalic capsule of a Brazilian
Development times of the 1st (SD = 0.6; n = 81), 2nd (SD = 1.0; n = 53) and 3rd instars (SD = 1.1; n = 67) were similar, each averaging three days; the 4th instar was the longest, with mean development time of 10 days (SD = 2.5; n = 316). Mean time for complete larval stage development was 19 days (SD = 5.2; n = 517). Mean development time for the pupal stage, at 26 °C, was two days (SD = 0.24, n = 50). The life span of adults, on average, at 26 °C, was three days for both males (SD = 0.70, n = 50) and females (SD = 0.65, n = 50). Development time of the Brazilian
High morphological similarities observed between the Brazilian
Studies on the genetic intraspecific divergence in some
The interspecific genetic divergence observed in our data is in accordance with results for other groups of
The large genetic distance (mean 9%) between Group B specimens (composed of specimens identified as
The placement of the Brazilian
Environmental conditions where the Brazilian
The size of last-instar larvae, represented by the ventral length of the head capsule, of the Brazilian
In this study we addressed the taxonomic problem involving the species named
Financial support was provided by PRONEX-CNPq/FAPEAM, INCT/ADAPTA, MCTI/INPA/PCI and a master’s scholarship provided by CAPES to the first author. We thank Dr. Jon Martin (University of Melbourne) and Dr. Masaru Yamamoto (Yamaguchi Prefecture) for sending specimens that allowed certification of species identities. Jeferson O. da Silva, Renato Tavares and Cláudio Monteiro Jr. helped in the fieldwork. We thank Natsumi H. Fearnside and Philip Fearnside for the English translation and revision. NH is a CNPq research fellow. VAS is a FAPEAM-CNPq DCR fellow. LMF was supported by a Visiting Expert Grant from the National Council for Scientific and Technological Development (PCI-CNPq/ MCTI/ INPA program).