RESUMEN
Nearly 230 species of biting midges have been recorded or described from Argentina; 38 of them are known from the Buenos Aires province and only one is cited from Martín García Island. This paper presents the results raised from six collecting trips which took place on the island during spring 2005, summer 2006 and autumn 2009. Diverse sampling sites including permanent and temporary aquatic environments were chosen, most of the ten sampling sites were ponds of diverse origin, some of these environments were covered with floating vegetation as Lemna gibba, Lemna minuscule, Salvinia biloba, Salvinia minima, Azolla filiculoides, Limnobium laevigatum, Pistia stratiotes, Spirodela intermedia, Wolffiella oblonga and Wolffia columbiana. Other sites were placed in urban and suburban areas. Adults were collected with sweep nets at sunrise and sunset and with light traps at intervals of four to five hours at night, depending on electricity availability on the island. Larvae and pupae were collected with different implements depending on characteristics of each surveyed aquatic habitat. In free standing water, they were captured with small sieves or hand pipettes and micropipettes, flotation techniques were utilized for sampling vegetated areas, free and rooted floating hydrophytes were extracted for removing insects among them. Thirteen species of Ceratopogonidae were collected, three of Atrichopogon Kieffer, three of Forcipomyia Meigen, two of Dasyhelea Kieffer, four of Culicoides Latreille, and one of Bezzia Kieffer, all representing new records from the island. Rev. Biol. Trop. 59 (3): 1183-1194. Epub 2011 September 01.
Alrededor de 230 especies de ceratopogónidos han sido registradas o descritas en Argentina, 38 de ellas son conocidas para la provincia de Buenos Aires y sólo una ha sido previamente citada para la Isla Martín García. En este trabajo se presentan los resultados obtenidos a partir de muestreos realizados en seis viajes a la isla durante la primavera de 2005, verano de 2006 y otoño de 2009; se seleccionaron diez sitios de muestreo con ambientes acuáticos permanentes y temporales. La mayoría de los muestreos se llevaron a cabo en cuerpos de agua de diverso origen; algunos de éstos se hallaban cubiertos con vegetación flotante compuesta por Lemna gibba, Lemna minuscule, Salvinia biloba, Salvinia minima, Azolla filiculoides, Limnobium laevigatum, Pistia stratiotes, Spirodela intermedia, Wolffiella oblonga y Wolffia columbiana; mientras que los restantes se realizaron en zonas urbanas y suburbanas. Los adultos se capturaron con redes entomológicas a la salida y puesta del sol y con trampas de luz a intervalos de cuatro a cinco horas por la noche, dependiendo de la disponibilidad de electricidad en la isla. Las larvas y pupas fueron recolectadas con diferentes metodologías según las características de los ambientes estudiados; en el agua libre se capturaron con tamices pequeños o pipetas y micropipetas, y en cuerpos de agua con vegetación se utilizó la técnica de flotación para separar los insectos de las hidrófitas flotantes y arraigadas. Se identificaron trece especies de Ceratopogonidae, 3 de Atrichopogon Kieffer, 3 de Forcipomyia Meigen, 2 de Dasyhelea Kieffer, 4 de Culicoides Latreille, y uno de Bezzia Kieffer, todos ellos representan nuevos registros para la isla.
Asunto(s)
Animales , Femenino , Masculino , Ceratopogonidae/clasificación , ArgentinaRESUMEN
The present work analyses the individual growth of Heleobia piscium in natural conditions in coastal drainage channels of the Multiple Use Natural Reserve Isla Martín García, Buenos Aires, Argentina. Isla Martín García is located in the Upper Río de la Plata, to the south of the mouth of the Uruguay river (34° 11' 25" S and 58° 15' 38" W). Monthly collections were made from July 2005 to July 2006 in the eastern part of the island (Arena Beach). The population of H. piscium showed a complex and dynamic structure of sizes during a long period of the annual cycle. Two cohorts could be detected. The Bertalanffy growth equation was: Lt = 6 (1-e -1.85 (t+0.38)) and Lt = 3.9 (1-e -0.19 (t+4.84)) for cohorts 1 and 2, respectively. The pattern of population growth displayed a staggered model, where the greatest growth is observed during the summer. The reproductive period occurred during six months, from the beginning of summer to middle of fall. Based on only one reproductive effort, this pattern is not similar to that of other cogeneric species already studied.
O presente trabalho analisa o crescimento individual de Heleobia piscium em condições naturais em poças costeiras da Reserva Natural de Usos Múltiplos Ilha Martín García, Buenos Aires, Argentina. A Ilha Martín García está localizada no Rio da Prata superior, ao sul da desembocadura do rio Uruguai (34° 11' 25" S e 58°15' 38" W). Amostras mensais foram analisadas entre os meses de julho de 2005 e julho de 2006, no setor este da ilha (Praia de Arena). A população de Heleobia piscium se caracterizou por uma complexa e dinâmica estrutura de talhas ao longo de grande parte do ciclo anual. Duas cohortes puderam ser detectadas. A equação de von Bertalanffy para a cohorte 1 foi: Lt = 6 (1-e -1.85 (t+0.38)). Para a cohorte 2: Lt = 3.9 (1-e -0.19 (t+4.84)). O padrão de desenvolvimento da população mostra um modelo escalonado, estendendo-se o período de maior crescimento durante toda a estação do verão. A temporada reprodutiva se manifestou durante seis meses, desde o princípio do verão até meados do outono. Este padrão baseado em um único esforço reprodutivo não se assemelha ao de outras espécies congenéricas já estudadas.