A new neotropical species of Larsia Fittkau, 1962 (Chironomidae: Tanypodinae) from Aechmea distichantha Lem. (Bromeliaceae) phytotelmata

SIRI AUGUSTO; DONATO MARIANO

Trondheim

Simposio; 18th International Symposium on Chironomidae; 2011

The cosmopolitan genus Larsia Fittkau 1962 is known by seven species in the Neotropical region (Ashe & O´Connor 2009, Oliveira & Silva 2011). Immatures of Larsia were found in lenticand lotic environments. The immatures of a new species of Larsia were collected in phytotelmata in northeastern Argentina. Phytotelmata are structures present in terrestrial plants which allow water to impound. The new species was collected from the the water held by the leaf axils of the bromelid Aechmea distichantha Lem. and reared to adult in laboratory. Aechmea distichantha is a bromeliad with an erect rosette of arching strap-shaped leaves, distributed in the deciduous, semideciduous and evergreen forests in southern Brazil, Bolivia, Paraguay, Uruguay and northern Argentina. The pupa of the new species bears an unusual thoracic horn for the genus, being this character very useful to distinguish this new species from other Larsia species. The thoracic horn is long and narrow, lacks a corona and the respiratory atrium is slightly rugose. The male of L. angusticornis shares the abdominal coloration pattern with L. lyra Sublette, L. marginella Malloch and L. gelhausi Oliveira et Silva. As in L. fittkaui Sublette et Sasa and L. labartheae Serpa-Filho the dorsomedial lobe of the female gonapophysis VIII is short and curved. The antennal length / mandible length ratio of L. angusticornis is the smallest for the genus. The larval cephalic setation of the new species fits with the generic description by Kowalyk (1985), but the setae S9, S10 and VP are arranged in line.