The immature stages of Labrundinia tenata ( Diptera : Chironomidae : Tanypodinae ) and redescription of the male

The immature stages of Labrundinia tenata Roback, 1987 (Diptera: Chironomidae: Tanypodinae) are de- scribed and illustrated and the male is redescribed. Larvae were collected in aquatic systems in southeastern Brazil, where they are associated with aquatic macrophytes. The three semaphoronts of L. tenata are recognized: (a) Male by the abdominal segments I pale brown, II-VI with brown transverse band along proximal margin, VII, VIII almost wholly brown; hypopygium brown; anterior margin of sternapodeme rounded, no distinct spur. (b) Pupa by the thoracic horn S-shaped and a shallow preapical groove; abdominal segment VII with two lateral setae. (c) Larva with posteroventral spine group; posterior parapod with single elongate claw serrated on inner margin and numerous simple claws.

In Brazil, although Labrundinia spp.have been recorded in many ecological studies (TRIVINHO-STRIXINO & STRIXINO 1993, HENRIQUES-OLIVEIRA et al. 2003, SIQUEIRA & TRIVINHO-STRIXINO 2005, ABURAYA & CALLIL 2007), yet they are poorly known taxonomically.Labrundinia tenata was described by ROBACK (1987a) from Colombia, based only on characters of the males and their immatures have thus far been unknown.In the present paper, the immatures stages of L. tenata are described and the male is redescribed in full detail.We present also information on the life-history of the species.

MATERIAL AND METHODS
Larvae were collected associated with aquatic macrophytes in small ponds from the state of São Paulo, Brazil and were reared in the laboratory to obtain pupae and adults as suggested by MENDES (2002).Specimens examined were slidemounted in Euparal, following the procedures outlined by PINDER (1983PINDER ( , 1986PINDER ( , 1989)).
Measurements are given as the range followed by the mean with the number of observed specimens in parenthesis if it differs from the number (n) stated at the beginning of the description.Seta counts are given only as the range.Humerals were incorporated into the dorsocentrals.
The material examined is deposited in the Reference Collection of Laboratório de Entomologia Aquática, Universidade Federal de São Carlos.One male with associated pupal and larval exuviae will be deposited in the Museu de Zoologia da Universidade de São Paulo, São Paulo, Brazil (MZUSP).

TAXONOMY
Labrundinia tenata Roback, 1987  ZOOLOGIA 26 (3): 541-546, September, 2009 Diagnostic characters.Labrundinia tenata can be separated from others species of the genus by the following combination of characters: male with abdominal segments I pale brown, II-VI with brown transverse band along proximal margin, VII, VIII almost wholly brown; hypopygium brown; anterior margin of sternapodeme rounded, no distinct spur.Pupa with thoracic horn S-shaped and a shallow preapical groove with cleft in upper margin; abdominal segment VII with two lateral setae.Larva with posteroventral spine group, lateroventral spine group indistinct; posterior parapod with single elongate claw serrated on inner margin and numerous simple claws.
The larvae of Labrundinia tenata were collected associated with aquatic macrophytes of the genus Salvinia in the Fazzari reservoir, which is located in a protected area in the city of São Carlos, in the campus of Universidade Federal de São Carlos, surrounded by cerrado fragment with low level of anthropic impact.This system is shallow (0.60 m depth), with acid water (pH 6.8), high level of dissolved oxygen (9.4 mg.L -1 ), low conductivity (8 µS.cm -1 ) and temperature ranging from 19-23ºC.
The larvae of Labrundinia are considered predators (COFFMAN & FERRINGTON 1996), feeding on small invertebrates, including other Chironomidae larvae.In this work, the larvae of L. tenata analyzed exhibited basically detritus in their digestive tracts, which shows a diversity of habits for the genus as indicated by HENRIQUES-OLIVEIRA et al. (2003).
The female remains unknown.

Table I .
Lengths (in µm) and proportions of legs of L. tenata , male.