BIOMETRY AND LIFE CYCLE OF Chironomus ... - SciELO

BIOMETRY AND LIFE CYCLE OF Chironomus calligraphus Goeldi 1905
(DIPTERA, CHIRONOMIDAE) IN LABORATORY CONDITIONS
Florencia L. Zilli, Luciana Montalto, Analía C. Paggi and Mercedes R. Marchese
SUMMARY
Chironomid larvae are important components of aquatic biota,
due to their abundance and participation in food webs, and
because they are considered environmental bioindicators. Many
laboratory studies have analyzed the effects of pollutants on chironomids,
especially on Chironomus calligraphus Goeldi, 1905.
However, little is known about the life cycle attributes of Chironomidae
(Diptera). The main pourpose of this study was to
analyze C. calligraphus life cycle under laboratory conditions.
The growth rate was almost constant between larval instars (r=
1.60 ±0.02), the immature development time (D) was 15 days
and the minimum generation time (G) was 18 days. According
to these results and field observations C. calligraphus has a
temperature-dependent life cycle, with several overlapped short
duration cohorts in spring-summer followed by one or two generations
of longer duration in winter.
BIOMETRÍA Y CICLO DE VIDA DE Chironomus calligraphus Goeldi, 1905 (DIPTERA, CHIRONOMIDAE) EN
CONDICIONES DE LABORATORIO
Florencia L. Zilli, Luciana Montalto, Analía C. Paggi y Mercedes R. Marchese
RESUMEN
Las larvas de quironómidos son componentes importantes
de la biota acuática por su participación en las tramas tróficas
y por ser bioindicadores de condiciones ambientales. Muchos
estudios de laboratorio han analizado los efectos de diferentes
contaminantes sobre quironómidos, especialmente sobre
Chironomus calligraphus Goeldi, 1905. Sin embargo, poco se
conoce sobre los atributos de su ciclo de vida. El objetivo de
este estudio fue analizar el ciclo de vida de C. calligraphus en
condiciones de laboratorio. La razón de crecimiento entre estadios
larvales fue aproximadamente constante (r= 1,60 ±0,02),
el tiempo de desarrollo (D) fue 15 días y el tiempo mínimo de
generación (G) fue 18 días. De acuerdo a estos resultados y a
observaciones realizadas en campo, C. calligraphus es una especie
con ciclo de vida temperatura-dependiente con generaciones
superpuestas de corta duración en primavera-verano y con una
o dos generaciones de mayor duración en invierno.
Introduction
Diptera Chironomidae is
the most abundant group of
insects in freshwater aquatic
systems (Pinder, 1983) with
larval stages associated principally
with benthic communities
and macrophytes (Trivinho-Strixino
and Strixino, 1991,
1999; Trivinho-Strixino et al.,
1998; Poi de Neiff and Neiff,
2006). The immature stages
of midges have an important
role acting as a link between
primary producers (phytoplankton
and benthic algae)
and consumers, mainly fishes,
but also birds and amphibians.
The larvae participate in
the first steps of the organic
matter cycle which is used
by detritivorous organisms
(Paggi, 1998). Due to their
high abundances throughout
the year, they contribute to a
large extent to the productivity
of aquatic systems. On the
other hand, they are widely
used as bioindicator species
of environmental conditions
(Paggi, 1999).
Although the importance
of Chironomidae in aquatic
systems of Neotropical regions
like the Paraná River
floodplains has been widely
pointed out, there is little information
on their population
dynamics and bionomic attributes
(Strixino, 1973; Trivinho-Strixino
and Strixino,
1989; Masaferro et al., 1991;
Corbi and Trivinho-Strixino,
2006). Nevertheless, it is difficult
to analyze these characteristics
on the field and laboratory
autoecological studies
are performed instead (Corbi
and Trivinho-Strixino, 2006).
Thus, an analysis of Chirono-
midae life cycle attributes is
necessary in order to increase
knowledge about aquatic biota
dynamics as well as environmental
health.
Two species of the Chironomus
genus: Chironomus (Chironomus)
xanthus Rempel,
1939 (=C. domizzi Paggi, 1979;
C. sancticaroli Trivinho-Strixino
and Strixino, 1982) and
Chironomus (Chironomus) calligraphus
Goeldi, 1905 (Paggi,
1979, 1998; Marchese and
Paggi, 2004) were recorded in
Argentina. C. calligraphus is a
pan-American chironomid with
KEYWORDS / Argentina / Chironomidae / Chironomus calligraphus / Life Cycle /
Received: 12/04/2007. Modified: 08/27/2008. Accepted: 08/29/2008.
Florencia L. Zilli. Licenciada
en Biodiversidad, Universidad
Nacional del Litoral (UNL),
Argentina. Becaria de Doctorado,
Instituto Nacional de
Limnología (INALI), Consejo
Nacional de Investigaciones
Científicas y Técnicas y Universidad
Nacional del Litoral,
(CONICET-UNL), Argentina.
Dirección: Laboratorio Bentos,
Instituto Nacional de Limnología,
Ciudad Universitaria,
Santa Fe (3000), Santa Fe, Argentina.
e-mail: florzeta1979@
yahoo.com.ar
Luciana Montalto. Doctora en
Ciencias Biológicas, Universidad
de Buenos Aires (UBA),
Becaria Postdoctoral, INALI
(CONICET-UNL), Argentina.
Analía C. Paggi. Doctora en
Ciencias Naturales, Universidad
Nacional de La Plata
(UNLP). Investigadora del Instituto
de Limnología Raúl A.
Ringuelet (CONICET-UNLP),
Argentina.
Mercedes R. Marchese. Profesora
de Biología (UNL). Investigadora
INALI (CONICET-
UNL), Argentina.
OCT 2008, VOL. 33 Nº 10
0378-1844/08/10/767-04 $ 3.00/0
767

BIOMETRÍA E CICLO DE VIDA DE Chironomus calligraphus Goeldi, 1905 (DIPTERA, CHIRONOMIDAE) EM
CONDIÇÕES DE LABORATÓRIO
Florencia L. Zilli, Luciana Montalto, Analía C. Paggi e Mercedes R. Marchese
RESUMO
As larvas de quironomídeos são componentes importantes da
biota aquática por sua participação nas tramas tróficas e por
serem bioindicadores de condições ambientais. Muitos estudos
de laboratório têm analisado os efeitos de diferentes contaminantes
sobre quironomídeos, especialmente sobre Chironomus
calligraphus Goeldi, 1905. No entanto, pouco se conhece sobre
os atributos de seu ciclo de vida. O objetivo deste estudo foi
analisar o ciclo de vida de C. calligraphus em condições de
laboratório. A razão de crescimento entre estágios larvais foi
aproximadamente constante (r= 1,60 ±0,02), o tempo de desenvolvimento
(D) foi de 15 dias e o tempo mínimo de geração (G)
foi de 18 dias. De acordo a estes resultados e a observações realizadas
em campo, C. calligraphus é uma espécie com ciclo de
vida temperatura-dependente com gerações superpostas de curta
duração em primavera-verão e com uma ou duas gerações de
maior duração no inverno.
a predominantly Neotropical
distribution. This
species was reported to
have a high potential as
a nuisance to humans in
the USA, mainly because
it has the ability to thrive
in a wide range of conditions
and habitats, including
small and temporary
waters (Spies, 2000;
Spies et al., 2002). There
are reports about its morphology
(Goeldi, 1905; Roback,
1962; Fittkau, 1965; Paggi,
1979; Spies et al., 2002), karyology
and DNA sequencing
(Spies et al., 2002) as well as
many ecotoxicology test studies
(Iannacone and Alvariño,
1998; Iannacone and Dale,
1999; Iannacone et al., 1999),
but there is no available information
about the life cycle of
this species. The present study
provides information about the
life cycle of C. calligraphus
under laboratory conditions.
Methods and Material
Sampling
Egg masses of Chironomus
calligraphus Goeldi, 1905
were collected in field waters
of Santo Tomé city (Santa
Fe, Argentina, 31°40’2.54”S
and 60°45’13.09”W) in January
2007 and transported to
the laboratory, conditioned in
recipients with environmental
water at 21.8 ±3.2ºC.
Laboratory rearing
The egg masses were placed
in Petri dishes and left up to
Figure 1. Chironomus calligraphus at larval instar IV. a: head capsule, ventral view, b: larva, lateral view.
the moment when the first
instar left the mucilaginous
mass that served for its nutrition.
The number of eggs per
mass, and the width (µm) and
length (µm) of each egg were
measured under an optic microscope.
After that period, the
larvae were separated and
cultured individually in 10
plastic aquaria (12×21×6cm)
with permanently oxygenated
water (1 lit) at room
temperature. The larvae were
fed with a finely ground suspension
of flaked fish food
(TetraMin ® , Germany) every
two days. Larvae were
collected daily from each
aquarium and the aquaria
were kept covered to retain
the adults at emergence. The
air temperature of 22.5-31ºC
held throughout the duration
of the study.
Life cycle and larval instars
The collected larvae (Figure
1) were fixed and conserved in
70% alcohol. The larvae head
capsule width (maximum ventral
width of the cephalic capsule
measured transversely to
the major body axis) and the
total body length (from the
anterior margin of the cephalic
capsule to the final portion
of the last abdominal segment)
were measured (µm) using an
optic microscope with a micrometric
scale. A population
growth curve showing the relationship
between total body
length (µm) and time (days)
was obtained. The larvae were
separated into instars according
to the relationship between
head capsule width and total
body length. In order to determine
the growth rate between
instars, the Dyar proportion
(r; Dyar, 1890) was calculated
considering its widespread application
in arthropods (Strixino,
1973).
The time up to eclosion, the
mean duration of each instar,
the immature development
time D (average time from
egg deposition to adult emergence,
when females were
available; Danks, 2006), the
minimum generation time G
(mean interval from oviposition
to the first progeny of the
next generation; Danks, 2006)
and the mean generation time
(G) of the population by determining
the lasting time of
emergence, were recorded.
The studied material was deposited
at the Instituto de Limnología
Dr. Raúl A. Ringuelet,
La Plata, Argentina.
Results and Discussion
The eggs measured 317.7
±20.0µm in length and 119.1
±10.3µm in width. The range
of variation in the number
of eggs per mass (369-374)
was lower than that registered
for tropical C. xanthus (500-
1045) by Trivinho-Strixino
and Strixino (1982). In this
sense, subtropical C. calligraphus
could have improved its
fitness by increasing the size
of each egg rather than the
number. The hatching period
was of approximately 3 days.
The larval instars were
clearly separated when measuring
the head capsule width
to total body length relation
(Figure 2). The data collected
about mean head capsule
width, total body length,
growth rate and duration of
the different larval instars of
C. calligraphus is summarized
in Table I. In the second
instar the larvae showed a
bottom exploratory behavior
and constructed the tubes.
They also started to develop
the tubules of the eight segments.
768 OCT 2008, VOL. 33 Nº 10

Figure 2. Relationship between head capsule width (µm) and total body
length (µm) of Chironomus calligraphus larval instars I to IV.
The r (Dyar) values obtained
were almost constant
(1.60 ±0.02) showing the accuracy
of this method in the
determination of C. calligraphus
larval growth rate. This
value was lower than that reported
for C. xanthus (1.70
±0.032) by Trivinho-Strixino
and Strixino (1982). The possibility
of using Dyar r values
is important for benthos,
as for those insects developing
some immature stages
on macrophytes, being less
probable to find the first instar
in the field, measures can be
estimated trough the r value
instead (Strixino, 1973).
The regression model
that best fitted for the relationship
between total
body length and time was
y= 9536.6+(1177.8-9536.6)/
(1+(x/6.8) 5.1 ) (R² = 0.987),
showing that size increased
continuously until reaching
an asymptote near the 15 th
day, remaining almost constant
thereafter (Figure 3).
C. calligraphus larvae incremented
their size mostly in
the earlier instars (I and II:
120.8%; II and III: 109.0%)
while a smaller increment
(74.6%) took place between
instars III and IV. The total
growth (instars I-IV) represented
an increment of
706.2%.
Instar I lasted 5 ±1.2 days,
with 1-2 days developing inside
the mucilaginous hatching
mass. Instar II lasted 3
±0.7 days and instar III, 6
±2.6 days. Instar IV lasted 10
±1.7 days, with approximately
8 days corresponding to the
transitional stage between larva
and pupa (commonly called
pre-pupa), probably due to the
fact that the changes occurring
in this metamorphosis step require
a large amount of extra
energy supply. The pupa stage
lasted 10 ±2.4 days and each
TABLE I
MEAN (±SD) HEAD CAPSULE WIDTH, GROWTH RATE, TOTAL BODY LENGTH AND
DURATION OF LARVAL INSTARS OF Chironomus calligraphus
Instars
Head capsule
width (µm)
Growth rate
(r)
Total body
length (µm)
Duration
(days)
I 115.2 ±6.9 1.58 1109.3 ±193.4 5 ±1.2
II 182.2 ±10.8 1.62 2449.1 ±701.4 3 ±0.7
III 295.3 ±19.1 1.60 5121.1 ±750.7 6 ±2.6
IV 472.8 ±30.9 1.60 8943.6 ±1672.7 10 ±1.7
Figure 3. Relationship between total body length
(µm) and time (days) of Chironomus calligraphus
larval instars I to IV. The approximate average
duration of instars is indicated.
Figure 4. Overlap between Chironomus calligraphus instars. The additional
life time of emerged adults is shown as a pointed line. E: egg;
Ll-LIV: larval instars I to IV; P: pupa, A: adult. The pre-pupa stage
is also indicated.
pupa remained in the tube of
the last larval instar (IV) for
1 or 2 days after it swam to
the surface, where the imago
emerged in only a few minutes
and lived without feeding
for 2 or 3 days. The minimum
immature development time
(D) was of 15 days and the
minimum time to complete
a generation (G) was of 18
days. Thus, as emergence took
an average time of 10 days
(with the highest emergences
between the 18 th and 22 nd day),
the average generation time
(G) was of 23 (18-28) days.
In the earlier stages overlapping
was low, with a synchronization
of larval instars
(Figure 4). In the last days of
the cycle an overlap was registered,
when instar IV larvae
(mostly as pre-pupa), pupae
and adults coexisted. For C.
xanthus, Trivinho-Strixino and
Strixino (1982) pointed out
that at high temperature (25°C
constant temperature) the fast
development of larvae tends to
become synchronized, favoring
a short emergence (3 days). In
the present case, although the
air temperature was in general
>25°C, the overlap in the last
immature stages favored long
emergence duration.
Many factors, such as phylogeny,
resource availability,
competence and interference
phenomenon, temperature,
habitat stability, etc. may determine
and affect the development
of insects (Jackson and
Sweeney, 1995; Danks, 2006).
The short duration of the life
cycle insures a conspicuous
population growth and increases
insect fitness. The cycle
is considered as short when
it lasts

life cycle of C. calligraphus,
its development is principally
conditioned by temperature
and life-cycle delays serve to
adjust development so as to
ensure seasonal coincidence
(Danks, 2006).
Therefore, subtropical C.
calligraphus could be described
as multivoltine, with
several overlapped cohorts
(at least four) of short duration
at high temperatures
(spring-summer) with high
rates of development and an
exponential population growth,
followed by one or two generations
of longer duration
in winter, when it probably
remains in a dormant stage.
ACKNOWLEDGEMENTS
This study was supported
by a grant from Universidad
Nacional del Litoral (UNL)
and Consejo Nacional de Investigaciones
Científicas y
Técnicas (CONICET). The
present paper is the Scientific
Contribution N° 828 of the
Instituto de Limnología “R.A.
Ringuelet” (ILPLA) La Plata,
Argentina.
References
Biever KD (1965) A rearing technique
for the colonization of
chironomid midges. Ann. Entomol.
Soc. Am. 58: 135-136.
Butler MG (1982) A 7-year life cycle
of two Chironomus species
in arctic Alaskan tundra ponds
(Diptera: Chironomidae). Can.
J. Zool. 60: 58-70.
Corbi JJ, Trivinho-Strixino S
(2006) Ciclo de vida de duas
espécies de Goeldichironomus
(Diptera, Chironomidae). Rev.
Bras. Entomol. 50: 72-75.
Danks HV (2006) Short life cycles
in insects and mites. Can. Entomol.
138: 407-463.
Dyar HG (1890) The number of
molts of Lepidopterus larvae.
Psyche 5: 420-422.
Fittkau EJ (1965) Revision der von
E. Goeldi aus dem Amazonasgebiet
beschriebenen Chironomiden
(Diptera). Chironomidenstudien
X. Beitr. Neotrop.
Fauna 4: 209-226.
Goeldi EA (1905) Os mosquitos no
Pará. Mem. Mus. Para. Hist.
Nat. Etnol. 4: 134-139.
Iannacone JA, Alvariño L (1998)
Acute ecotoxicity of the organophosphate
insecticide temephos
to Chironomus calligraphus
Goeldi (Diptera: Chironomidae).
Acta Entomol. Chil.
22: 53-55.
Iannacone JA, Dale WE (1999)
Protocolo de bioensayo ecotoxicológico
para evaluar metales
pesados contaminantes de
agua dulce con Chironomus
calligraphus (Diptera: Chironomidae)
y Moina macrocopa
(Crustacea: Cladocera), en el
Río Rímac. Lima, Perú. Rev.
Per. Entomol. 41: 111-120.
Iannacone JA, Alvariño L, Gutiérrez
A (1999) Cinco ensayos
ecotoxicológicos para evaluar
metales pesados en el agua
dulce. Bol. Soc. Quím. Perú
65: 30-45.
Jackson JK, Sweeney BW (1995)
Egg and larval development
times for 35 species of tropical
stream insects from Costa
Rica. J. North. Am. Benthol.
Soc. 14: 115-130.
Marchese M, Paggi AC (2004) Diversidad
de Oligochaeta (Annelida)
y Chironomidae (Diptera)
del Litoral fluvial argentino. In
Aceñolaza FC (Ed.) Temas de
la Biodiversidad del Litoral
Fluvial Argentino. INSUGEO.
Tucumán, Argentina. pp. 217-
223.
Masaferro J, Paggi AC, Rodrígues
Capítulo A (1991) Estudio poblacional
de los quironómidos
(Insecta Diptera) de la laguna
de Lobos, Provincia de Buenos
Aires, Argentina. Graellsia 47:
129-137.
Paggi AC (1979) Dos nuevas especies
del género Parachironomus
Lenz (Diptera:
Chironomidae) y nuevas citas
de Quironómidos para la
República Argentina. Physis
38: 47-54.
Paggi AC (1998) Chironomidae. In
Morrone JJ, Coscarón S (Eds.)
Biodiversidad de Artrópodos
Argentinos. Una Perspectiva
Biotaxonómica. Ediciones Sur.
La Plata, Argentina. pp 327-
337.
Paggi AC (1999) Los Chironomidae
como indicadores de calidad
de ambientes dulceacuícolas.
Rev. Soc. Entomol. Argent. 58:
202-207.
Pinder LCV (1983) The larvae of
Chironomidae (Diptera) of the
holartic region Introduction. In
Wiederholm T (Ed.) Chironomidae
of the Holartic Region:
Keys and Diagnoses. Entomol.
Scan. Supl. pp 7-10.
Poi de Neiff A, Neiff JJ (2006)
Riqueza de especies y similaridad
de los invertebrados que
viven en plantas flotantes de la
planicie de inundación del río
Paraná (Argentina). Interciencia
31: 220-225.
Roback SS (1962) Some new
Tendypedidae from the Canal
Zone. Not. Nat. 355: 1-10.
Spies M (2000) Non-biting `nuisance´
midges (Diptera, Chironomidae)
in urban southern
California, with notes on taxonomy,
ecology and zoogeography.
In Hoffrichter O (Ed.)
Late 20 th Century Research
on Chironomidae: an Anthology
from 13 th International
Symposium on Chironomidae.
Aachen, Germany. pp.
621-628.
Spies M, Sublette JE, Sublette MF,
Wülker WF, Martin J, Hille
A, Miller MA, Witt K (2002)
Pan-American Chironomus calligraphus
Goeldi, 1905 (Diptera,
Chironomidae): Species
or complex? Evidence from
external morphology, kariology
and DNA sequencing. Aquat.
Insects 24: 91-113.
Strixino S (1973) A Largura da
Cabeça na Determinação das
Fases Larvais de Chironomidae
na Represa do Lobo. Thesis.
Universidade Federal de
São Carlos. Brazil. 167 pp.
Strixino G, Trivinho-Strixino S
(1985) A temperatura e o desenvolvimento
larval de Chironomus
sancticaroli (Diptera:
Chironomidae). Rev. Bras.
Zool. 3: 177-180.
Trivinho-Strixino S, Strixino G
(1982) Ciclo de vida de Chironomus
sancticaroli Strixino
and Strixino, (Diptera, Chironomidae).
Rev. Bras. Entomol.
26: 183-189.
Trivinho-Strixino S, Strixino G
(1989) Observations on the
reproductive biology of a Neotropical
chironomid (Diptera,
Chironomidae). Rev. Bras.
Biol. 33: 207-216.
Trivinho-Strixino S, Strixino G
(1991) Estrutura da comunidade
de insetos aquáticos associados
à Pontederia lanceolata
Nuttal. Rev. Bras. Biol.
53: 103-111.
Trivinho-Strixino S, Strixino G
(1999) Insectos dípteros quironomídeos.
In Ismael D, Valenti
WC, Matsumura-Tundisi T,
Rocha O (Eds.) Biodiversidade
do Estado de São Paulo, Brasil.
pp 141-148.
Trivinho-Strixino S, Gessner FA,
Correia L (1998) Macroinvertebrados
associados a macrófitas
aquáticas das lagõas marginais
da Estação Ecológica de Jataí
(Luiz Antônio. SP). Anais do
VIII Seminário Regional de
Ecologia 3: 1189-1198.
770 OCT 2008, VOL. 33 Nº 10