CECOAL   02625
CENTRO DE ECOLOGIA APLICADA DEL LITORAL
Unidad Ejecutora - UE
artículos
Título:
Number and duration of the juvenile instars of the Neotropical grasshopper Cornops aquaticum (Acrididae: Leptysminae) in Argentina.
Autor/es:
CAPELLO SOLEDAD; FRANCESCHINI M. CELESTE
Revista:
INTERCIENCIA
Editorial:
INTERCIENCIA
Referencias:
Lugar: Caracas; Año: 2014 vol. 39 p. 255 - 259
ISSN:
0378-1844
Resumen:
Cornops aquaticum is a semiaquatic grasshopper that lives in close association with Pontederiaceae, especially the genus Eichhornia. In the native range of distribution of this grasshopper, there is only information about life history traits of populations from Brazil and Uruguay. So, the aim of this work was to assess the number of juvenile instars and duration of nymphal development of C. aquaticum in summer and spring nymphs from Argentinean populations. Wild newly emerged nymphs were individually reared in Corrientes and Santa Fe city under the influence of the local climate, without direct sun exposure. In both sites, nymphs showed males with five instars and females with five or six instars. Female with six instars was significantly more frequent in the summer nymphs. The highest mortality of nymphs occurred mainly in the first two instars. Nymphal development was significantly longer in nymphs from the summer peak than the spring peak. Longer duration of nymphal development in females than in males was determined by females with six juvenile instars. Our results, as well as the results obtained in other sites of South America about the life cycle of C. aquaticum, show that when the instar number and nymphal development are the life history traits desirable to study in a species, rearing should be carried out at several geographical sites of its distribution, and in the periods when new hatched nymphs have the peaks of highest abundance in wild populations. Different juvenile instars in native populations respect to quarantine populations of C. aquaticum show the importance to consider life history traits throughout the native range and the effect of environmental factors as useful information for the possible use of this grasshopper as a biological control agent of Eichhornia crassipes in non-native areas.