Description of a new species of Simulium (Simulium) Latreille and redescription of Simulium (Simulium) metallicum Bellardi from Guatemala : Diptera : Simuliidae

Okazawa, Takao; Onishi, Osamu

doi:10.7601/mez.31.167

Cited by 11 publications

(5 citation statements)

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“…In Guatemala, Takaoka (1982) compared the larval distribution of S.metallicum s.s . with that of S.horacioi , a distinct member of the S.metallicum complex described from morphological criteria ( Okazawa & Onishi 1980). Grillet et al .…”

Section: Introductionmentioning

confidence: 99%

Distribution of the Simulium metallicum complex in Mexico in relation to selected environmental variables

Millest

Cheke

Greenwood

1999

Medical Vet Entomology

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Larvae of the Simulium metallicum complex (Diptera: Simuliidae) were collected from three foci of human onchocerciasis in Mexico. Specimens were separated into five different cytotypes, identified by morphological characteristics (head pattern and body colour) or polytene chromosome features. Differences were found between foci in the cytotype composition of the S. metallicum complex. Nearly all specimens were cytotype A in the Chamula (97%) and Soconusco (86%) foci. In the Oaxaca focus, however, cytotype I predominated (63%) with 14% cytotype A. Cytotype I comprised only 6% of specimens in the Soconusco focus and was very rare in the Chamula focus. Cytotypes B and H occurred only rarely in all three foci. Cytotype X was found only in Oaxaca. Environmental variables were measured at the collection sites and canonical correspondence analysis (CCA) was used to investigate the associations of cytotype distributions with the following factors: stream size, amount of shade, water clarity, pH, temperature and altitude. Members of the S. metallicum species complex were found to be differentially distributed according to stream conditions and there was a significant correlation between their distributions and the environmental variables. The most important factor in canonical axis 1 of the CCA was pH (t-value -4.38) with temperature (-2.48) and altitude (2.19) having some influence, but the other variables were unimportant. In the second canonical axis, pH (-3.52) was the only variable having a significant effect. Thus, cytotype A was associated with high pH, high temperature and low altitude; B was associated with similar sites but with higher temperatures and at lower average elevations. Cytotype H was found at the centres of the ranges of these variables, I at sites with the lowest temperatures and highest altitudes and X in rivers with the lowest pH.

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Section: Introductionmentioning

confidence: 99%

Distribution of the Simulium metallicum complex in Mexico in relation to selected environmental variables

Millest

Cheke

Greenwood

1999

Medical Vet Entomology

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“…This is not surprising as these species are morphologically similar to S. metallicum, especially S. horacioi (see Shelley et al 2002: 175, Table 4). Simulium horacioi was described by Okazawa & Onishi (1980), although Takaoka (see Tada 1983) suggested that S. horacioi was a junior synonym of S. racenisi Ramírez Pérez. Later, Conn et al (1988Conn et al ( , 1989 described 11 sibling species within S. metallicum s.l.…”

Section: Resultsmentioning

confidence: 99%

DNA barcoding of Neotropical black flies (Diptera: Simuliidae): Species identification and discovery of cryptic diversity in Mesoamerica

Hernández‐Triana

2015

Zootaxa

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Although correct taxonomy is paramount for disease control programs and epidemiological studies, morphology-based taxonomy of black flies is extremely difficult. In the present study, the utility of a partial sequence of the COI gene, the DNA barcoding region, for the identification of species of black flies from Mesoamerica was assessed. A total of 32 morphospecies were analyzed, one belonging to the genus Gigantodax and 31 species to the genus Simulium and six of its subgenera (Aspathia, Eusimulium, Notolepria, Psaroniocompsa, Psilopelmia, Trichodagmia). The Neighbour Joining tree (NJ) derived from the DNA barcodes grouped most specimens according to species or species groups recognized by morphotaxonomic studies. Intraspecific sequence divergences within morphologically distinct species ranged from 0.07% to 1.65%, while higher divergences (2.05%-6.13%) in species complexes suggested the presence of cryptic diversity. The existence of well-defined groups within S. callidum (Dyar & Shannon), S. quadrivittatum Loew, and S. samboni Jennings revealed the likely inclusion of cryptic species within these taxa. In addition, the suspected presence of sibling species within S. paynei Vargas and S. tarsatum Macquart was supported. DNA barcodes also showed that specimens of species that are difficult to delimit morphologically such as S. callidum, S. pseudocallidum Díaz Nájera, S. travisi Vargas, Vargas & Ramírez-Pérez, relatives of the species complexes such as S. metallicum Bellardi s.l. (e.g., S. horacioi Okazawa & Onishi, S. jobbinsi Vargas, Martínez Palacios, Díaz Nájera, and S. puigi Vargas, Martínez Palacios & Díaz Nájera), and S. virgatum Coquillett complex (e.g., S. paynei and S. tarsatum) grouped together in the NJ analysis, suggesting they represent valid species. DNA barcoding combined with a sound morphotaxonomic framework provided an effective approach for the identification of medically important black flies species in Mesoamerica and for the discovery of hidden diversity within this group.

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“…Coscaron (1991) used head pattern as an important character for differentiating between some Neotropical species and variations in head pattern and body coloration of larvae have been used to distinguish both morphospecies, e.g. S. metallicum Bellardi from S. horacioi (=Okazawa & Onishi, 1980), and cytotypes of a species complex, e.g. S. metallicum (Conn et al, 1989;Millest, 1990).…”

Section: Introductionmentioning

confidence: 99%

The value of the larval head pattern for differentiating Simulium exiguum s.l. and S. gonzalezi (Diptera: Simuliidae) in the onchocerciasis focus of Ecuador

Charalambous

Lowry

Lowell

et al. 1997

Bull. Entomol. Res.

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In the Esmeraldas focus of onchocerciasis in Ecuador, the larvae of the primary vector Simulium exiguum Roubaud are found in sympatry with the non-vector S. gonzalezi Vargas & Diaz Najera. Distinguishing the pre-ultimate stage larvae of these two species usually relies on the the pattern of markings on the cephalic apotome. These patterns appear either as dark spots against a pale cuticle (positive head pattern) or as pale spots within a darkened area of the cuticle (negative head pattern). Larvae of S. exiguum s.l. usually exhibit positive or no head patterns whilst those of S. gonzalezi usually have negative head patterns. The purpose of this paper was to investigate head pattern variation (scored in one of six categories) in (polytene) chromosomally identified larvae of the two species and cytotypes of S. exiguum from three collection sites in Ecuador (including one in the onchocerciasis focus). The head patterns of a total of 1183 larvae were studied. Chromosomal identification of penultimate instar larvae revealed only the presence of the Cayapa and Quevedo cytotypes of S. exiguum (n=208). Both cytotypes exhibited a wide range of head patterns from positive to negative. The results indicate that negative head patterns cannot be used to reliably distinguish between larvae of S. exiguum s.l. and S. gonzalezi. All except one larva with negative head patterns were females (n=53), suggesting that head pattern in this species complex might be a sex-linked character.

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Description of a new species of Simulium (Simulium) Latreille and redescription of Simulium (Simulium) metallicum Bellardi from Guatemala : Diptera : Simuliidae

Abstract: The JapanSociety of Medical Entomology and Zoology (Jap. J. Sanit, Zool. Vol. 31 No. 3 p, 167-1791980] Description of a new species of Simulium (Simulium)

Cited by 11 publications

References 1 publication

Distribution of the Simulium metallicum complex in Mexico in relation to selected environmental variables

Distribution of the Simulium metallicum complex in Mexico in relation to selected environmental variables

DNA barcoding of Neotropical black flies (Diptera: Simuliidae): Species identification and discovery of cryptic diversity in Mesoamerica

The value of the larval head pattern for differentiating Simulium exiguum s.l. and S. gonzalezi (Diptera: Simuliidae) in the onchocerciasis focus of Ecuador

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