Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

Influence of ecoregion and river type on neotropical Chironomidae (Diptera)

from humid mountain to semiarid lowland

Edgardo Javier Ignacio Pero1*; https://orcid.org/0000-0002-6335-8654

Silvia Elena Torrejon2; https://orcid.org/0000-0003-0675-6645

Carlos Molineri3; https://orcid.org/0000-0003-2662-624X

1. Instituto de Biodiversidad Neotropical (IBN), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET),

Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán (UNT), Tucumán,

Argentina, Universidad de San Pablo-Tucumán, Tucumán, Argentina; peroedgardo@gmail.com (Correspondence*)

2. Instituto de Ecorregiones Andinas (INECOA), Consejo Nacional de Investigaciones Científicas y Técnicas

(CONICET), Facultad de Ciencias Agrarias, Universidad Nacional de Jujuy, Alberdi 47, C. P. 4600. S. S de Jujuy,

Jujuy, Argentina; torrejonelena@gmail.com

3. Instituto de Biodiversidad Neotropical (IBN), Consejo Nacional de Investigaciones Científicas y Técnicas

(CONICET), Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán (UNT),

Tucumán, Argentina; carlosmolineri@gmail.com

Received 09-VI-2022. Corrected 09-I-2023. Accepted 18-I-2023.

ABSTRACT

Introduction: Chironomidae (Diptera) is the most widespread and abundant aquatic insect family in freshwater

ecosystems. Chironomids are considered good indicators of water quality but are seldom identified at the genus

level in broad spatial scale studies.

Objective: To identify environmental conditions associated with chironomids in an altitudinal gradient.

Methods: We compared ecoregions, river types, and seasons, for chironomids in neotropical streams and rivers

(18 river sites; 2014-2018; Yungas rainforest and Western Chaco dry forest, Argentina). We used non-metric

multidimensional scaling, dissimilarity, envfit analysis and rank-abundance curves.

Results: Chironomid “assemblages” matched both ecoregions and river types. However, ecoregions presented a

better fit with species composition. The stenothermal taxa of Orthocladiinae were dominant at high elevations

and the eurythermal Chironominae in lowland rivers. Altitude, water temperature and conductivity were impor-

tant. Seasonal differences were smaller than ecoregional differences.

Conclusions: Ecoregions, altitude, water temperature and conductivity correlated with chironomid communi-

ties. Orthocladiinae were dominant at high elevations and Chironominae in lowland rivers.

Key words: non-biting midges; Tanypodinae; Diamesinae; Podonominae; macroecology, rivers, South America.

RESUMEN

Influencia de la ecorregión y tipo de río en Chironomidae neotropical (Diptera)

desde las montañas húmedas hasta tierras bajas semiáridas

Introducción: Chironomidae (Diptera) es la familia de insectos acuáticos más extendida y abundante en los

ecosistemas dulceacuícolas. Los quironómidos se consideran buenos indicadores de la calidad del agua, pero

rara vez se identifican a nivel de género en estudios de amplia escala espacial.

Objetivo: Identificar las condiciones ambientales asociadas a los quironómidos en un gradiente altitudinal.

https://doi.org/10.15517/rev.biol.trop..v71i1.50081

AQUATIC ECOLOGY

2Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

INTRODUCTION

Aquatic macroinvertebrates are widely

used to understand general biological distri-

butional patterns and are also used extensively

as indicators of the biological quality of fresh-

water ecosystems (Resh et al., 1995). Chiron-

omidae (Diptera) is the most widespread of

aquatic insect families (Ferrington, 2008) and

is the most abundant insect group in aquatic

ecosystems (Armitage et al., 1995; Shadrin et

al., 2017; Shadrin et al., 2019). Their immature

stages (larva and pupa) are very important in

aquatic trophic webs; constituting a consider-

able part of the diet of other invertebrates,

fishes, amphibians and birds (Armitage et al.,

1995). In addition, different taxonomic levels

of Chironomidae (subfamily, genus or spe-

cies) have been considered good indicators of

water quality for biomonitoring (Molineri et

al., 2020). However, due to taxonomic difficul-

ties, chironomids are often only identified at

family level in broad spatial scale studies and

biomonitoring programs (Lencioni et al., 2018;

Rossaro et al., 2022).

Many studies carried out in the Holartic

region have recorded variation in chironomid

larval assemblages along spatial and altitudinal

gradients (Lindergaard & Brodensen, 1995;

Rossaro et al., 2006). These studies reported

that Orthocladiinae, Diamesinae, and Prodi-

amesinae are the predominant taxa in moun-

tain streams while Chironominae (especially,

Métodos: Comparamos ecorregiones, tipos de ríos y estaciones para quironómidos en arroyos y ríos neotropi-

cales (18 sitios en ríos; 2014-2018; en un bosque tropical de Yungas y un bosque seco del Chaco Occidental,

Argentina). Utilizamos escalamiento no métrico multidimensional, disimilitud, análisis de envfit y curvas de

rango-abundancia.

Resultados: Los “ensamblajes” de quironómidos coincidieron tanto con las ecorregiones como con los tipos de

ríos. Sin embargo, las ecorregiones presentaron un mejor ajuste con la composición de especies. Los taxones

estenotérmicos de Orthocladiinae fueron dominantes en las elevaciones altas y los euritermales de Chironominae

en los ríos de las tierras bajas. La altitud, la temperatura del agua y la conductividad fueron importantes. Las

diferencias estacionales fueron menores que las diferencias ecorregionales.

Conclusiones: las ecorregiones, la altitud, la temperatura del agua y la conductividad se correlacionaron con las

comunidades de quironómidos. Orthocladiinae fue dominante en los sitios altos y Chironominae en los ríos de

tierras bajas.

Palabras clave: Quironómidos; Tanypodinae; Diamesinae; Podonominae; macroecología; ríos; Sudamérica.

Chironomini) increase toward the lowlands.

Water temperature and current regime were

proposed to be the main factors related to

the distributional patterns observed in these

assemblages (Eggermont & Heiri, 2012; Run-

dle et al., 2007). In Europe, several studies

that have included data from Chironomidae at

genus level, found that the composition was

concordant with river classifications, such as

geomorphological division (Schöll & Haybach,

2004), ecotypes (Puntí et al., 2007; Puntí et al.,

2009), or ecoregions (Plóciennik & Karaouzas,

2014). However, the differences among assem-

blages were small in some cases (Puntí et al.,

2007), indicating an important overlap between

chironomid assemblages and suggesting that

a top-down classification of streams (using

ecotypes) does not necessarily imply exclusive

assemblages of chironomids.

Some studies of Chironomidae from the

Neotropical regions have reported similar dis-

tributional patterns along altitudinal gradients.

Orthocladiinae, Diamesinae and Podonominae

are more frequent in high elevation streams,

while Chironominae are dominant in lowland

rivers (Acosta & Prat, 2010; Medina et al.,

2008; Principe et al., 2008; Rodríguez Garay

et al., 2020; Scheibler et al., 2014; Tejerina &

Malizia, 2012; Tejerina & Molineri, 2007; Vil-

lamarin et al., 2021; Zanotto-Arpellino et al.,

2015). Chironomidae studies from neotropical

lowlands streams and rivers in semiarid zones

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

such as those of the Western Chaco dry forest,

are still scarce. Nevertheless, recent studies that

analyzed benthic macroinvertebrates distribu-

tion in rivers of the Western Chaco ecoregion

revealed that chironomids are the most abun-

dant invertebrate group (Leiva et al., 2020; Pero

et al., 2019).

In addition, it is also important to know the

seasonal variations of freshwater ecosystems

features across contrasting climatic but contig-

uous regions, mainly because of the uncertain

challenges of climate change (Tonkin et al.,

2019) and for the inference of reference con-

ditions for the bioassessment (Hawkins et al.,

2010). Some studies associated seasonal dis-

turbances in streams, such as spates and floods,

as important features structuring Chironomidae

assemblages (Langton & Casas, 1998; Rossaro

et al., 2006). The relative abundance of Chi-

ronomidae subfamilies also showed temporal

variation in neotropical streams, such as those

of Yungas forest. For example, Orthocladiinae

was better represented during low water period

whereas Chironominae was more abundant in

high-water period (Tejerina & Malizia, 2012).

Nonetheless, Acosta and Prat (2010) found that

in both the dry and rainy seasons, the subfamily

Orthocladiinae was dominant, surpassing 70 %

of the total of Chironomidae in high elevation

streams of Andean region of Peru.

It is important to know the distributional

variations of these aquatic insects in reference

conditions along the landscape to improve

water quality bioassessments (Nicasio & Juen,

2015) and extend our knowledge about how

climatic and ecoregional gradients influence

the distribution and function of the freshwater

neotropical biota. Therefore, our main goal was

to explore the vertical and spatial distribution

of chironomids in Northwestern Argentina,

expanding the study area in the Yungas Forest

with respect to Tejerina and Malizia (2012) and

including a comparative analysis with rivers of

the little-explored and highly threatened West-

ern Chaco ecoregion (which represent the first

specific study on chironomids for this region).

Hence, we aimed to answer: (1) How do the

composition and structure of Chironomidae

assemblages (genus and subfamilies) vary

between Yungas and Western Chaco ecoregions

and among mountains, foothills and lowlands

in Northwestern Argentina? (2) How do com-

position and structure of Chironomidae vary

between hydrological seasons (low and high-

water periods)? (3) How is Chironomidae dis-

tribution related to the environmental features

of the studied rivers?

MATERIALS AND METHODS

Study Area: The study area is located

between (26°-28° S & 66°-64° W) and covers

approximately 20 000 km2 including most of

Tucumán province and its limits with San-

tiago del Estero province in Northwestern

Argentina (Fig. 1). In this study, we sampled

reaches of fluvial channels located in two dif-

ferent ecoregions: Yungas subtropical cloud

forest and Western Chaco dry forest (Brown &

Pacheco, 2006).

The Yungas subtropical cloud forest or

Yungas forest is a narrow belt of mountain

rainforest, ranging from 400 to over 3 000

m.a.s.l. (Brown, 2000). The climate is warm

and humid, with annual average temperatures

ranging from 14 to 26 °C and rainfall from

1 000 to 2 500 mm (Brown et al., 2001). The

Yungas forest is stratified into 3 vegetation

belts. In general, Yungas altitudinal levels are

not considered sub-ecoregion units, but in this

study, we evaluated them as differentiated units

within the Yungas forest because each altitudi-

nal level presents particular climatic features

and floristic composition (Brown & Pacheco,

2006). The high montane forest (1 500-3 000

m.a.s.l.) contains monospecific tree stands that

are usually either Alnus acuminata (Kunth) or

Podocarpus parlatorei (Pilg.). Annual rainfall

reaches 1 000 mm. The low montane for-

est (700-1 500 m.a.s.l.) has the most diverse

vegetation, with many evergreen species, and

is dominated by Cinnamomum porphyrium

(Griseb.) Kosterm. and Blepharocalyx salicifo-

lius (Kunth) O. Berg. The low montane forest

also has the highest precipitation (2 000 mm

annual) and least seasonal hydrological regime.

4Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

The foothill forest (400-700 m a.s.l.) contains

deciduous trees and is dominated by Tipuana

tipu (Benth.) Kuntze and Enterolobium contor-

tisiliquum (Vell.) Morong. The annual rainfall

varies between 1 000-1 500 mm during the

wet season, and the 6-month dry season (≤ 50

mm rainfall) extends from June to November

(Brown et al., 2001).

The Western Chaco ecoregion is a vast

sedimentary fluvial plain formed by the streams

and rivers that run Northwest to Southeast

and includes parts of Northwestern Argentina,

Southeastern Bolivia, Northwestern Paraguay,

and Southwestern Brazil (Great South Ameri-

can Chaco). The headwaters are located in the

mountains, outside the region to the West, and

they transport great quantities of sediments into

the region. Mean annual temperatures range

between 19 and 24 °C. Annual rainfall varies

between 400 and 900 mm, with most precipita-

tion falling in the summer and little falling in

the winter (Minneti, 1999). The vegetation is

composed of dry forests and segregated grass-

lands. This ecoregion is classified into three

sub-ecoregions: Arid Chaco, Semiarid Chaco,

and Chaco Serrano (Brown & Pacheco, 2006).

Fig. 1. Study area and sampling site locations. Sites codes: HM = high montane; LM = low montane; FH = foothill forest;

CS = Chaco Serrano; SC = Semiarid Chaco.

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

Only the last two are represented in the study

area. The Chaco Serrano is part of the Western

border of the ecoregion and is characterized by

low mountain topography. The Semiarid Chaco

occupies the greater portion of the ecoregion

and is a continuous xerophytic and semi-

deciduous forest.

Within the study area, five river types

(montane forest [I], foothill forest [II], Chaco

Serrano [III], Semiarid Chaco pebble rivers

[IV], Semiarid Chaco sand rivers [V]) have

been identified and included in three large

groups: Mountains, Foothills, and Lowlands

(Plains) rivers (Pero et al., 2020). In the clas-

sification of Pero et al. (2020), a combination

of ecoregions and topography was the main cri-

teria to define river types and the physical vari-

ables as altitude, grain size, water temperature

and turbidity were key parameters to develop

the river typology.

Survey design and methods: We studied

18 sites (Fig. 1). Sites were distributed across

ecoregions and sub-ecoregions as follows: 12

in the Yungas subtropical cloud forest (4 in

high montane [HM], 4 in low montane [LM],

and 4 in foothill forests [FH]), and 6 in the

Western Chaco (2 in Chaco Serrano [CS] and 4

in Semiarid Chaco [SC]). Each site consisted of

a stream reach ~100 m long. We chose sites that

were minimally disturbed, without industrial

impact, and with native riparian vegetation at

least 100 m wide.

Data from 13 of the 18 sites (HM3, HM4,

LM4, FH1, FH2, FH3, FH4, CS1, CS2, SC1,

SC2, SC3 and SC4) were collected between

2014 and 2018 by the authors. Data for the 5

other sites (HM1, HM2, LM1, LM2, LM3)

were obtained from the IBN (Neotropical Bio-

diversity Institute, National Council of Tech-

nological and Scientific Research - National

University of Tucumán) database and are pub-

lished elsewhere (Tejerina & Malizia, 2012).

The IBN sites were sampled between 2005

and 2007 following the same collection pro-

cedures. Climate conditions were similar dur-

ing these 2 periods according to local climate

databases, and both periods corresponded to

the ENSO phase of El Niño according to the

Oceanic Niño Index (ONI) (http://www.cpc.

noaa.gov/products/analysis_monitoring/enso-

stuff/ensoyears.shtml). In addition, previous

studies in the region observed that macroinver-

tebrate assemblage composition and structure

changes seasonally rather than annually (Mesa,

2012). All sites were sampled once at the end

of the low-water period (October-December)

and once at the end of the high-water period

(March-June) for two years, with the exception

of 2 sites that were sampled only during the low

water period (FH3, SC3).

Chironomidae sampling: At each site we

collected quantitative and qualitative samples.

Three quantitative samples were collected with

a Surber net (0.09 m2 area with a 300 μm mesh),

and were subsequently pooled into a single,

composite sample. We took these samples in

fast-water habitat units (riffles or runs, sensu

Hawkins et al., 1993) that were separated by 50

m along a longitudinal transect. The qualitative

samples consisted of samples collected with a

D-frame net (300 μm mesh), a kick-net (500

μm mesh), and by manual sampling. Manual

sampling included directly picking specimens

from boulders, cobbles, leaves, and algae. The

qualitative sampling took approximately 30

minutes to cover all habitats. Riffles, pools,

and marginal vegetation habitats were most

common. All samples were preserved in etha-

nol 96º. Quantitative data were used to analyze

abundance patterns, and the combined quanti-

tative and qualitative data were used to analyze

presence-absence data. We brought all samples

to the lab after collection, where we processed

and identified each entire sample. In the labo-

ratory, chironomids larvae were sorted, counted

and identified to morphospecies using a ste-

reomicroscope with a 10X magnification (Ros-

saro et al., 2022). From each morphospecies,

we chose those corresponding to the fourth

stage larvae to make permanent microscope

slides. Larvae were mounted complete (includ-

ing head capsules and body) following the

conventional method proposed by Epler (2001).

Larvae were identified using a compound

6Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

microscope with 40-100X magnification to

genus level using taxonomic keys (Andersen et

al., 2013; Epler, 1995; Epler, 2001; Merritt &

Cummins, 1996; Trivino-Strixino & Strixino,

1995; Wiederholm, 1983) and other taxonomic

works (Cranston & Krosch, 2011; Prat et al.,

2017). The rest of the material that was not

used to make permanent microscope slides was

preserved in 75 % ethanol.

Environmental variables: We character-

ized the environmental setting at each site. We

recorded elevation (m.a.s.l.) with a Garmin

eTrex 20™ global positioning system (with

an accuracy of 3 meters). Channel width (m),

discharge (m3/s), water temperature (°C), pH,

and conductivity (μS/cm) were recorded at

every visit. We estimated discharge by mea-

suring cross-sectional area, taking depth mea-

surements every 25 cm (for streams ≤ 11 m

wide) or 1 m (for rivers ≥ 11 m wide) along 1

cross-sectional transect across the channel, and

measuring velocity with a velocity meter at

2/3 the depth at each point (Global Water Flow

Probe FP111). Physicochemical variables were

measured with a Horiba™ multi-probe water

quality checker U-50 series.

Data analyses: All statistical analyzes

and graphs were produced via the R platform

(version 3.6.1, R Core Team, 2019) and via

Microsoft Office Excel 2007.

Rank-abundance curves: We used

rank-abundance (RA) curves (also known as

dominance-diversity curves) to compare how

assemblage structure varied across the differ-

ent ecoregions, river types, and seasons. RA

curves, in combination with species identity,

can provide insight into specific patterns of

species diversity, dominance, rarity, and com-

position (e.g., Pero et al., 2019). We used these

analyses to complement the multivariate analy-

ses and allow more detailed observations of

compositional and structural differences among

assemblages. Groups of dominant taxa, and

taxa that occurred exclusively in each ecore-

gion and sub-ecoregion were identified. The 3

most abundant taxa at each site were consid-

ered the dominant taxa for each ecoregion and

sub-ecoregion.

Dissimilarity: We used the Sørensen and

the Positive Matching indices (PMI, Dos San-

tos & Deutsch, 2010) to analyze the presence-

absence data. We used the Bray-Curtis and

Dissim indices (Nieto et al., 2017) to estimate

compositional dissimilarity between Chiron-

omidae assemblages based on our abundance

data. The PMI can vary between 0 and 1 and

represents the mean proportion of “positive

matches” relative to the complete list of taxa

that could occur at a site. The PMI covers the

range of richness encompassed by the two lists

– i.e., the smaller and longer ones. Hence, if

2 lists of different lengths are compared, for

example of 10 and 100 specimens, and the PMI

is 0.3, that result indicates that the 2 lists share

30 % of taxa, on average, given the list sizes

range from the smaller to the longer one (Dos

Santos & Deutsch, 2010). In contrast, Euclide-

an and Bray-Curtis distances are 2 dissimilarity

indexes that are frequently used in ecological

analyses (Nollet & De Gelder, 2014). However,

both of these indices are strongly influenced by

dominant species and are only weakly affected

by rare species (Valentin, 2012) and are there-

fore not as useful when there are gradual

changes in composition along a gradient. The

Dissim index can be used when the observed

taxa are assumed to have been sampled from

a common regional pool of species. The Dis-

sim Index assesses whether assemblages are

similar based on both the taxa present and their

abundance. Thus, 2 sites would be considered

more similar whether they grouped consistently

near each other after successive orderings of

sites by increasing values of consecutive taxa

abundance (Nieto et al., 2017).

We used multivariate analyses to deter-

mine if differences in assemblage composition

among sites were associated with regional

classifications. We used Nonmetric Multidi-

mensional Scaling (NMDS) based on dissimi-

larity values obtained from presence-absence

and abundance data to illustrate whether the

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

positions of sites in taxa space were concordant

with ecoregional and typological classifica-

tions. We interpreted how discrete the ecore-

gions and river types were by drawing a convex

polygon around each group of river types on

the NMDS plot.

It is well known that benthic macroinver-

tebrate assemblages can vary markedly with

season (Poff & Ward, 1989). We therefore sepa-

rated the data by low and high waters periods to

test whether the differences among ecoregions,

sub-ecoregions and river types were greater

than the seasonal differences within each site.

For the description of the structure and

composition of Chironomidae subfamilies, we

estimated the relative abundance of each sub-

family for each ecoregion and river type.

Envfit analysis: To assess the set of envi-

ronmental variables that best correlate with

biological ordinations, vectors (selected envi-

ronmental variables) were fitted to the existing

NMDS plots of sample dissimilarities using

the function “envfit” (from R package vegan).

The envfit scales these vectors based on their

correlation coefficient, and the resulting plot

allows to quickly identify the most important

variable gradients represented by the NMDS

plot (Clarke & Ainsworth, 1993).

RESULTS

Composition and structure of Chiron-

omidae larvae assemblages at subfamily

level: We collected 11 724 Chironomidae lar-

vae across sampling sites (without counting

data from the IBN database). In the total

dataset, we identified 34 genera belonging to

five subfamilies. The subfamilies Chirono-

minae and Orthocladiinae showed the highest

abundance (47.3 % and 46.1 % respectively),

Tanypodinae constituted 5.7 %, while Diamesi-

nae and Podonominae showed the lowest abun-

dance (0.85 and 0.01 % respectively). Genera

richness was similar among Orthocladiinae,

Chironominae and Tanypodinae (11, 10 and 10

respectively), whereas Podonominae comprised

2 genera and Diamesinae only 1 genus.

The relative abundance of the five Chi-

ronomidae subfamilies varied across the ecore-

gions. Orthocladiinae was more abundant in

Yungas forest and high elevation sites and

decreased downstream, but including Chaco

Serrano sites. Chironominae showed the oppo-

site pattern, being dominant in Semiarid Chaco

and lower elevation sites. Diamesinae had a

relative low abundance, peaking in the highest

Yungas vegetation level (between 2 170 and

1 200 m.a.s.l.) and decreasing toward foothill

forest (between 700 and 400 m.a.s.l.). This

subfamily was absent in the Chaco ecoregion.

Podonominae were recorded in one site at high

montane forest and with very low abundance.

Tanypodinae had low abundance in most of

the sites but had a peak of 12 % in Semiarid

Chaco sites.

Composition and structure of Chiron-

omidae larvae assemblages at genus level:

Cricotopus was the most abundant taxa in all

Yungas regions and at the two hydrological sea-

sons. Some genera were recorded exclusively

in Yungas forest streams. Barbadocladius and

Genus 10 were only present in high montane

forest and Genus X was present in high and

low montane forest, Parametriocnemus was

found in all subecoregions from Yungas for-

est but was not recorded in Western Chaco.

The genera Parochlus and Podonomus from

Podonominae subfamily were only recorded

at high montane forest. The genera Apsectro-

tanypus and Larsia (Subfamily Tanypodinae)

and Paraheptagyia (Subfamily Diamesinae)

were only present in rivers from high and low

montane forests. Within streams and rivers

from Western Chaco, the more abundant gen-

era were Onconeura (Orthocladiinae), Rheota-

nytarsus and Polypedilum (Chironominae). In

addition, some genera were found exclusively

in Semiarid Chaco rivers, mainly from the

subfamily Chironominae: Cryptochironomus,

Harnischia 1, Robackia, Saetheria; and Tany-

podinae: Procladius, Nilotanypus and Clinot-

anypus. The genera Lopescladius, Onconeura

(Orthocladiinae), Rheotanytarsus, Tanytarsus

8Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

and Polypedilum (Chironominae) were present

in all ecoregions and river types.

The results included new records of some

genera for North-western Argentinean prov-

inces. Robackia, Cryptochironomus, Saetheria

(Chironominae), possibly Denopelopia, Lab-

rundinia, Tanypus and Procladius (Tanypo-

dinae) were recorded for the first time for

Tucumán province; Clinotanypus and Thiene-

mannimyia (Tanypodinae) for Tucumán and

Santiago del Estero provinces; Pseudochirono-

mus (Chironominae) and Nilotanypus (Tanypo-

dinae) for Santiago del Estero.

Dissimilarity: The overall structure of the

Chironomidae assemblages was concordant

with the ecoregional and river typology clas-

sifications based on either presence-absence or

abundance datasets (Fig. 2). NMDS axis 1 from

both abundance and presence-absence analyses

segregated two groups: one composed of the

Yungas sites, which included river types I and

II, and another composed of Western Chaco

sites, which included river types III, IV and

V. The seasonal differences among sites were

much lower than the ecoregional and typologi-

cal dissimilarities.

Correlations among abiotic and biotic

ordinations: According to the envfit analyses,

the axes of the NMDS plots were significantly

correlated with some abiotic features (Table 1)

of the rivers (Table 2). Finally, the grouping

of the Yungas assemblages, mainly from high

and low montane forest (river type I) was more

related to higher elevations, while Western

Fig. 2. Non-metric multidimensional scaling (NMDS) plot of Chironomidae samples dissimilarity at the genus level using

abundance data (Dissim index) with best correlated environmental variables from Envfit analysis. HM = high montane; LM

= low montane; FH = foothill forest; CS = Chaco Serrano; SC = Semiarid Chaco. l = low waters; h = high waters.

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

Chaco assemblages (river types III, IV and V)

were strongly related to high values of water

temperature, conductivity and channel width

(Fig. 2). Foothills forest assemblages (river

types II) had an intermediate position in the

observed biotic-abiotic gradient.

DISCUSSION

We found that Chironomidae assemblages’

distribution corresponded with the landscape

analysed units, both ecoregions and river types.

However, the ecoregional classification better

fitted chironomid distribution. In addition, the

composition of Chironomidae assemblages at

subfamily level along the altitudinal gradient

studied was very similar to the ones described

in other studies (Lindergaard & Brodersen,

1995; Principe et al., 2008; Tejerina & Malizia,

2012). Orthocladiinae was dominant at higher

elevation sites and Chironominae was more

abundant at lowland rivers. Chironomidae

TABLE 1

Associations between environmental variables (vectors) and the non-metric multidimensional scaling (NMDS) ordination

plot of Chironomidae samples dissimilarity at the genus level using abundance data (Dissim index) (dimensions 1 and 2)

using the envfit function (R package vegan)

Vectors Dimension 1 Dimension 2 R2P

Altitude -0.73 -0.69 0.43 0.001

Discharge 0.49 0.87 0.04 0.319

Channel width 0.99 0.01 0.29 0.001

Water temperature 0.68 0.73 0.28 0.001

Electric Conductivity (EC) 0.67 0.74 0.40 0.001

pH 0.72 -0.69 0.05 0.253

TABLE 2

Environmental variables measured at study sites (mean values)

Elevation

(m.a.s.l.)

Discharge

(m3 s -1)

Channel

width (m)

Water

temperature (°C)

Conductivity

(μS/cm) pH

HM1 2 170 0.57 8.9 12.7 57.0 7.0

HM2 1 300 0.14 1.9 18.7 126 6.7

HM3 1 622 0.36 3.6 10.6 78.5 8.1

HM4 1 394 0.09 1.7 12.7 68.8 7.5

LM1 925 2.04 7.1 17.1 124 6.6

LM2 680 0.54 8.9 21.0 447 7.5

LM3 860 0.12 3.7 18.7 287 7.0

LM4 1 126 0.04 1.3 16.9 226 8.3

FH1 711 0.93 7.1 19.1 52.5 7.2

FH2 543 5.26 23 16.2 86.7 7.6

FH3 713 0.03 1.4 18.8 246 8.3

FH4 590 0.22 6.0 14.9 70.5 7.9

CS1 761 3.71 21 19.9 556 7.5

CS2 649 7.57 28 18.5 737 7.8

SC1 429 1.58 9.9 22.2 2 370 7.7

SC2 398 1.37 7.8 25.4 2 576 7.7

SC3 307 5.53 74 28.5 504 8.4

SC4 291 8.12 38 20.2 848 8.1

10 Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

distribution was related to the variations of

environmental features along the landscape,

as was reported in several previous studies in

other regions (Acosta & Prat, 2010; Rodríguez

Garay et al., 2020; Villamarín et al., 2021),

mainly elevation, water temperature and con-

ductivity. Seasonal differences in Chironomi-

dae assemblages were weaker than ecoregional

ones, as it was observed for other invertebrate

groups in the study area (Pero et al., 2019; Pero

et al., 2020).

Our results provide information that helps

to understand how different classification sys-

tems reflect the natural variability that exists

along the landscape and altitudinal gradients.

The Chironomidae assemblages corresponded

with the ecoregional scheme in a broad spatial

scale, but typology also allowed subdividing

them by finer river types. Similarly, other stud-

ies that tested river typologies distinguished

groups of Chironomidae assemblages based

on river types (Plóciennik & Karaouzas, 2014;

Puntí et al., 2009; Schöll & Haybach, 2004).

However, differences among river types were

not strong, indicating certain overlap between

chironomid assemblages with the established

ecotypes, as it was reported by Puntí et al.

(2007) for Mediterranean streams in Spain

and also suggesting that a top-down classifi-

cation of streams (using ecotypes) does not

necessarily imply exclusive assemblages of

chironomids.

The segregation of Chironomidae assem-

blages among regions and river types was most

strongly related to broad spatial scale variables,

such as altitude, and associated physiochemi-

cal variables, such as water temperature or

conductivity. As it was recorded in previous

studies in neotropical streams (Acosta & Prat,

2010; Tejerina & Malizia, 2012), the presence

of taxa from the subfamilies Podonominae and

Diamesinae, and the dominance of Orthocla-

diinae was related to high elevation sites with

low water temperature and conductivity. The

dominance of Chironominae in lowland rivers

with higher values of water temperature and

conductivity observed in our study was also

evidenced in other neotropical regions (Leiva

et al., 2020). In addition, we found that in cer-

tain lowland river types, with higher levels of

conductivity, the subfamily Tanypodinae was

more important, in terms of its relative abun-

dance, than in the other sub-ecoregions and

river types. For example, the genus Procladius,

belonging to that subfamily, was very abun-

dant. This genus was found to be resistant and

abundant in other areas of high salinity (Wolf

et al., 2009). These results showed that local

environmental features could also influence

Chironomidae assemblage composition.

The findings of our study support the

proposal that topography in conjunction with

biogeographical history of assemblages could

act synergistically as drivers of assemblage

composition in the South American geographi-

cal context (Pero et al., 2019). In our study

area, topography varied throughout the South

American biogeographical transition zone that

separates the High Andean (including the high-

er areas of Yungas) and the Amazon (including

lower areas of Yungas and Chaco) biogeo-

graphical regions (Morrone, 2014). In addition,

Dos Santos et al. (2018) revealed that the dis-

tribution of Ephemeroptera assemblages was

strongly influenced by the segregation of “cool

adapted” taxa all across and toward the East

and Southeast of the Andes, and “warm adapt-

ed” taxa to the foothills and lowlands located

toward the west and Northwest of the Andes.

Similarly, Chironomidae assemblages could

also be influenced by both the biogeographical

and ecological South American context. Finer

levels of taxonomical identifications could add

more information about biogeographical pat-

terns (Rossaro et al., 2022). For example, the

genus Cricotopus in the Andes is quite com-

plex, and many taxa were recently considered

as subgenera of this group. According to recent

studies, Oliveiriella (recorded in many sites of

our study area, Tejerina & Paggi, 2009) is not a

genus but a subgenus of Cricotopus (Andersen

et al., 2013; Prat et al., 2017). In addition, the

diversity of Rheotanytarsus (Chironominae) is

very high in Latin America with many species

to be described (Dantas et al., 2020), and this

is an additional problem. Hence, further studies

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

about taxonomical and distributional aspects

of Chironomidae are still necessary to better

understand their ecology and biogeography in

the neotropical region.

Seasonal differences in Chironomidae

assemblages were lower than ecoregional ones,

which showed that temporal variations would

not affect the regional classifications tested.

No exclusive assemblages were distinguished

or associated to any hydrological season com-

pared (low or high water period), in contrast to

the observed for chironomid summer samples

in Mediterranean streams (Puntí et al., 2007).

Similarly, Acosta and Prat (2010) found that in

both the dry and rainy seasons, the subfamily

Orthocladiinae was dominant in high elevation

streams of Andean region. Nevertheless, we

found greater differences in chironomids abun-

dance rather than in their genera composition

between seasons, generally showing the lowest

abundance during high water periods when

spates and floods are frequent, as was reported

by other studies (Tejerina & Malizia, 2012).

The information gathered in our study

about the assemblages of Chironomidae

allows us to better understand the relationships

between the landscape and the distribution

of biota from the perspective of a biological

group little studied in the region. In addition,

our results support the use of ecoregions and

river typologies to improve our ability to estab-

lish the reference conditions for South Ameri-

can fluvial ecosystems. Finally, our findings

expand our knowledge about the ecology and

distribution of neotropical freshwater chirono-

mid assemblages, providing data from little-

explored and highly threatened ecoregions.

Ethical statement: the authors declare

that they all agree with this publication and

made significant contributions; that there is no

conflict of interest of any kind; and that we fol-

lowed all pertinent ethical and legal procedures

and requirements. All financial sources are

fully and clearly stated in the acknowledge-

ments section. A signed document has been

filed in the journal archives.

ACKNOWLEDGMENTS

We are grateful to the research group of

IBN (Instituto de Biodiversidad Neotropical)

for assistance and help in collecting trips.

Thanks also to Eva Tejerina for help in some

specimens’ identification, to Luciana Cristobal

for help editing the image of the study area and

to Eduardo Domínguez for his comments on

the manuscript. This manuscript was supported

by fellowships from ANPCyT (National Agen-

cy of Scientific and Technological Promotion)

and CONICET (National Council of Scientific

Research, Argentina) and the following grants:

ANPCyT PICT 1067-2012, PIP 845 and P-UE

CONICET 0099.

REFERENCES

Acosta, R., & Prat, N. (2010). Chironomidae assemblages

in high altitude streams of the Andean region of Peru.

Fundamental and Applied Limnology, 177, 57–79.

Andersen, T., Cranston, P. S., & Epler, J. H. (2013). The

larvae of Chironomidae (Diptera) of the Holartic

Region. Keys and diagnoses. Insect Systematics and

Evolution, 66, 387–556.

Armitage, P., Cranston, P. S., & Pinder, L. C. V. (1995). The

Chironomidae. The biology and ecology of non-biting

midges. Chapman and Hall.

Brown, A. D. (2000). Development threats to biodiversity

and opportunities for conservation in the mountain

ranges of the upper Bermejo River basin, NW Argen-

tina and SW Bolivia. Ambio, 29, 445–449.

Brown, A. D., Grau, H. R., Malizia, L. R., & Grau, A.

(2001). Argentina. In M. Kapelle & A. D. Brown

(Eds.), Bosques Nublados del Neotrópico (pp. 623–

659). INBio.

Brown, A. D., & Pacheco, S. (2006). Propuesta de actuali-

zación del mapa ecorregional de la Argentina. In A.

Brown, U. Martínez Ortiz, M. Acerbi, & J. Corcuera

(Eds.), La situación ambiental argentina 2005 (pp.

28–31). Fundación Vida Silvestre, Argentina.

Clarke, K. R., & Ainsworth, M. (1993). A method of

linking multivariate community structure of environ-

mental variables. Marine Ecology Process Series, 92,

205–219.

Cranston, P. S., & Krosch, M. (2011). Barbadocladius

Cranston and Krosch, a new genus of Orthocladiinae

(Diptera: Chironomidae) from South America. Neo-

tropical Entomology, 40, 560–567.

12 Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

Dantas, G. P., Araujo, A. A. H., & Hamada, N. (2020). A

new species of Rheotanytarsus Thienemann & Bause

(Diptera: Chironomidae) from Peruvian Andes, with

updated key to South American species. Zootaxa,

4722, 195–200.

Dos Santos, D. A., & Deutsch, R. (2010). The positive

matching index: a new similarity measure with opti-

mal characteristics. Pattern Recognition Letters, 31,

1570–1576.

Dos Santos, D. A., Molineri, C., Nieto, C., Zuñiga, M. C.,

Emmerich, D., Fierro, P., Pessacq, P., Ríos-Touma,

B., Márquez, J., Gomez, D., Salles, F. F., Encalada,

A. C., Principe, R., Gómez, G. C., Zarges, C. V., &

Domínguez, E. (2018). Cold/Warm stenothermic

freshwater macroinvertebrates along altitudinal and

latitudinal gradients in Western South America: A

modern approach to an old hypothesis with updated

data. Journal of Biogeography, 45, 1571–1581.

Eggermont, H., & Heiri, O. (2012). The chironomid-tempe-

rature relationship: expression in nature and palaeo-

environmental implications. Biological Reviews of

the Cambridge Philosophical Society, 87(2), 430–56.

Epler, J. H. (1995). Identification Manual for the Larval

Chironomidae (Diptera) of Florida. Department of

Environmental Protection, Florida.

Epler, J. H. (2001). Identification Manual for the Lar-

val Chironomidae (Diptera) of North and South

Carolina. A guide to the taxonomy of the midges of

the southeastern United States including Florida

(Special Publication SJ2001-SP13). North Carolina

Department of Environmental and Natural Resour-

ces, Raleigh NC and St. Johns River Management

District.

Ferrington, L. (2008). Global diversity of non-biting mid-

ges (Chironomidae; Insecta-Diptera) in freshwater.

Hydrobiologia, 595, 447–455.

Hawkins, C. P., Bisson, P. A., Bryant, M., Decker, L., Gre-

gory, S. V., McCullough, D. A., Overton, K., Reeves,

G., Steadman, R. J., & Young, M. (1993). A hierarchi-

cal approach to classifying habitats in small streams.

Fisheries, 18, 3–11.

Hawkins, C. P., Olson, J. R., & Hill, R. A. (2010). The

reference condition: predicting benchmarks for eco-

logical and water-quality assessments. Journal of the

North American Benthological Society, 29, 312–343.

Langton, P. H., & Casas, J. (1998). Changes in chironomid

assemblage composition in two Mediterranean mou-

ntain streams over a period of extreme hydrological

conditions. Hydrobiologia, 390, 37–49.

Leiva, M., Marchese, M., & Diodato, L. (2020). Structure,

distribution patterns and ecological responses to

hydrological changes in benthic macroinvertebrate

assemblages in a regulated semi-arid river: baseline

for biomonitoring studies. Marine and Freshwater

Research, 72, 200–212.

Lencioni, V., Cranston, P. S., & Makarchencko, E. A.

(2018). Recent advances in the study of Chirono-

midae: An overview. Journal of Limnology, 77, 1–6.

Lindergaard, C., & Brodensen, K. P. (1995). Distribution of

Chironomidae (Diptera) in the River Continnum. In

P. Craston (Ed.), Chironomids from Genes to Ecosys-

tems (pp. 257–271). CSIRO Publications.

Medina, A. I., Scheibler, E. E., & Paggi, A. C. (2008). Dis-

tribución de Chironomidae en dos sistemas fluviales

ritronicos (Andino-serrano) de Argentina. Revista de

la Sociedad Entomológica Argentina, 67, 69–79.

Merritt, R. W., & Cummins, K. W. (1996). An introduction

to the Aquatic Insects of North America. Kendall/

Hunt Publishing Company.

Mesa, L. M. (2012). Interannual and seasonal variability

of macroinvertebrates in monsoonal climate streams.

Brazilian Archives of Biology and Technology, 55,

403–410.

Minneti, J. L. (1999). Atlas climático del Noroeste Argenti-

no. Laboratorio Climatológico sudamericano, Funda-

ción Zon Caldenius.

Molineri, C., Tejerina, E. G., Torrejón, S. E., Pero, E. J. I.,

& Hankel, G. E. (2020). Indicative value of different

taxonomic levels of Chironomidae for assessing the

water quality. Ecological Indicators, 108, 105703.

Morrone, J. J. (2014). Biogeographical regionalization of

the Neotropical region. Zootaxa, 3782, 1–110.

Nicasio, G., & Juen, L. (2015). Chironomidae as indicators

in freshwater ecosystems: an assessment of the litera-

ture. Insect Conservation and Diversity, 8, 393–403.

Nieto, C., Dos Santos, D. A., Izquierdo, A., & Grau, H. R.

(2017). Modelling beta diversity of aquatic macroin-

vertebrates in High Andean wetlands. Journal of

Limnology, 76, 555–570.

Nollet, L. M. L., & De Gelder, L. S. P. (2014). Handbook

of water analysis 3. CRC Press.

Pero, E. J. I., Georgieff, S. M., Gultemirian, L. M., Rome-

ro, F., Hankel, G. E., & Domínguez, E. (2020).

Ecoregions, climate, topography, physicochemical,

or a combination of all: Which criteria are the best

to define river types based on abiotic variables and

macroinvertebrates in neotropical rivers? Science of

the Total Environment, 738, 140303.

Pero, E. J. I., Hankel, G. E., Molineri, C., & Domínguez,

E. (2019). Correspondence between stream benthic

macroinvertebrate assemblages and ecoregions in

northwestern Argentina. Freshwater Science, 38,

64–76.

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

Plóciennik, M., & Karaouzas, I. (2014). The Chironomidae

(Diptera) fauna of Greece: ecological distribution

and patterns, taxa list and new records. Annales de

Limnologie, 50, 19–34.

Poff, N. L., & Ward, J. V. (1989). Implications of strea-

mflow variability and predictability for lotic com-

munity structure: a regional analysis of streamflow

patterns. Canadian Journal of Fisheries and Aquatic

Science, 46, 1805–1817.

Prat, N., Paggi, A., Ribera, C., Acosta, R., Ríos-Touma, B.,

Villamarín, C., Rivera, F., Ossa, P., & Rieradevall,

M. (2017). The Cricotopus (Oliveiriella) (Diptera:

Chironomidae) of the High Altitude Andean Streams,

with Description of a New Species, C. (O.). rierade-

vallae. Neotropical Entomology, 47, 256–270.

Principe, R. E., Boccolini, M. F., & Corigliano, M. C.

(2008). Structural and Spatio-temporal dinamycs of

Chironomidae fauna (Diptera) in Up-land and Low-

lands fluvial habitats of the Chocancharava River

Basin (Argentina). International Review of Hydrobio-

logy, 93, 342–357.

Puntí, T., Rieradevall, M., & Prat, N. (2007). Chironomidae

assemblages in reference condition in Mediterranean

streams: environmental factors, seasonal variability

and ecotypes. Fundamental and Applied Limnology,

170, 149–165.

Puntí, T., Rieradevall, M., & Prat, N. (2009). Environmen-

tal factors, spatial variation and specific requirement

of Chironomidae in Mediterranean reference streams.

Journal of the North American Benthological Society,

28, 247–265.

R Core Team. (2019). R: A language and environment for

statistical computing. R Foundation for Statistical

Computing. http://www.R-project.org/

Resh, V., Norrish, R. H., & Barbour, M. T. (1995). Design

and implementation of rapid assessment approa-

ches for water resource monitoring using benthic

macroinvertebrates. Australian Journal of Ecology,

20, 198–219.

Rodríguez Garay, G. N., Paggi, A. C., & Scheibler, E.

E. (2020). Chironomidae assemblages at different

altitudes in Northwest Argentina: the role of local

factors. Anais da Academia Brasileira de Ciências,

92, e20190953.

Rossaro, B., Lencioni, V., Boggero, A., & Marziali, L.

(2006). Chironomids from Southern Alpine running

waters: ecology, biogeography. Hydrobiologia, 562,

231–246.

Rossaro, B., Marziali, L., Montagna, M., Magoga, G.,

Zaupa, S., & Boggero, A. (2022). Factors controlling

morphotaxa distributions of Diptera Chironomidae in

freshwaters. Water, 14, 1014.

Rundle, S. D., Bilton, D. T., & Foggo, A. (2007). By wind,

wings or water: body size, dispersal and range size

in aquatic invertebrates. In A. G. Hildrew, D. G.

Raffaelli, & R. Edmonds-Brown (Eds.), Body size:

the structure and function of aquatic ecosystems (pp.

186–209). Cambridge University Press.

Scheibler, E. E., Roig-Juñent, S. A., & Claps, M. C. (2014).

Chironomid (Insecta: Diptera) assemblages along an

Andean altitudinal gradient. Aquatic Biology, 20,

169–184.

Schöll, F., & Haybach, A. (2004). Typology of large Euro-

pean rivers according to their Chironomidae com-

munities (Insecta: Diptera). Annales de Limnologie,

40, 309–316.

Shadrin, N. V., Anufriieva, E. V., Belyakov, V. P., & Bazho-

ra, A. I. (2017). Chironomidae larvae in hypersaline

waters of the Crimea: diversity, distribution, abundan-

ce and production. The European Zoological Journal,

84(1), 61–72.

Shadrin, N. V., Belyakov, V. P., Bazhora, A. I., & Anufriieva,

E. V. (2019). The role of salinity as an environmental

filtering factor in the determination of the Dipte-

ra taxonomic composition in the Crimean waters.

Knowledge & Management of Aquatic Ecosystems,

2019(420), 3.

Tejerina, E., & Malizia, A. (2012). Chironomidae (Diptera)

larvae assemblages differ along an altitudinal gra-

dient and temporal periods in a subtropical montane

stream in Northwest Argentina. Hydrobiologia, 686,

41–54.

Tejerina, E., & Molineri, C. (2007). Comunidades de

Chironomidae (Diptera) en arroyos de montaña del

NOA: Comparación entre Yungas y Monte. Revista de

la Sociedad Entomológica Argentina, 66, 169–177.

Tejerina, E. G., & Paggi, A. C. (2009). A new Neotropical

species of Oliveiriella Wiedenbrug & Fittkau (Dipte-

ra: Chironomidae) from Argentina, with description

of all its life stages. Aquatic Insects, 31, 91–98.

Tonkin, J. D., Poff, N. L., Bond, N. R., Horne, A., Merritt,

D. M., Reynolds, L. V., Olden, J. D., Ruhi, A., &

Lytle, D. A. (2019). Prepare river ecosystems for an

uncertain future. Nature, 570, 301–303.

Trivino-Strixino, S., & Strixino, G. (1995). Larvas de Chi-

ronomidae (Diptera) do estado de São Paulo. Guia de

identificação e diagnose dos gêneros. Universidade

Federal de São Carlos.

Valentin, J. L. (2012). Ecologia numérica: uma introdução

à análise multivariada de dados ecológicos. Editora

Interciência.

Villamarín, C., Villamarín-Cortez, S., Salcido, D. M.,

Herrera-Madrid, M., & Ríos-Touma, B. (2021).

Drivers of diversity and altitudinal distribution of

14 Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71: e50081, enero-diciembre 2023 (Publicado 27 de enero, 2023)

chironomids (Diptera: Chironomidae) in the Ecua-

dorian Andes. Revista de Biología Tropical, 69,

113–126.

Wiederholm, T. (1983). Chironomidae of Holartic region

- Key and diagnosis (Part 1). Larvae. Entomologica

Scandinavica, 19, 1–457.

Wolf, B., Kiel, E., Hagge, A., Krieg, H. J., & Feld, C. K.

(2009). Using the salinity preferences of benthic

macroinvertebrates to classify running waters in

brackish marshes in Germany. Ecological Indicators,

9, 837–847.

Zanotto-Arpellino, J. P., Príncipe, R. E., Oberto, A. M., &

Gualdoni, C. M. (2015). Variación espacio-temporal

de Chironomidae (Diptera) bentónicos y derivantes

en un arroyo serrano en Córdoba, Argentina. Iherin-

gia, 105, 41–52.