Abstract
Dichroplus exilis is a widely distributed species in Southern South America. Although there have been reports of D. exilis as an agricultural pest, some recent observations suggest that the damage attributed to D. elongatus may actually have been caused by D. exilis. This study was conducted to determine the postembryonic life cycle stages, fertility and food consumption of this species under controlled conditions (30 degrees C, 14L-10D, 40% RH). Individuals employed belong to the laboratory-hatched first generation (F1), from adults (n = 64, female = 28, male = 36) collected in natural grasslands near Rafaela, Santa Fe province in North-Eastern Argentina. Three cohorts of 16, 17 and 20 individuals were monitored independently in acetate tubes on a daily basis, until death of the last insect. Average fecundity was 381.84, 38.54 eggs per female. Egg-pod incubation time was 14.4, 1.08 days and six nymphal instars were recorded. Nymphal development time was 41.38, 0.71 days (I = 8.73, 0.20; II = 6.38, 0.24; III = 5.64, 0.33; IV = 7.15; 0.43; V=9.76, 0.54; IV = 7.85, 0.95). The recorded food consumption was 9.89, 1.08 (mg/ind/day) for nymphs IV, 18.04, 0.73 (mg/ind/day) for nymphs V-IV, 16.76, 1.06 (mg/ind/day) for pre-reproductive males, 28.09, 1.81 (mg/ind/day) for pre-reproductive females, 7.71,0.91 (mg/ind/day) for reproductive males and 13.06, 0.71 (mg/ind/day) for reproductive females, while the average adult food consumption, regardless of sex and reproductive status, was 16.41, 4.32 mg/day. Average food consumption of adult females was 17.47, 1.15 mg, and was significantly higher than that of males (10.83, 0.91mg). Data obtained in this study showed that D. exilis exhibits at least some of the biological attributes needed to configure an actual or potential agricultural pest, albeit not yet recognized as such. Field monitoring of grasshopper communities in areas where damage by D. exilis is suspected is envisaged in order to determine its possible status as a pest.
Highlights
Dichroplus exilis (Giglio-Tos) es un melanoplino de amplia distribución geográfica en la región sur de América del Sur; se encuentra en Uruguay, Paraguay, Sur de Brasil (Rio Grande do Sul) y en el norte y gran parte del centro de la Argentina (Carbonell et al 2006)
Data obtained in this study showed that D. exilis exhibits at least some of the biological attributes needed to configure an actual or potential agricultural pest, albeit not yet recognized as such
Estudio bio-ecológico sobre siete especies del género Dichroplus Stal (Orthoptera, Acrididae)
Summary
Parámetros biológicos: Los individuos empleados en este estudio correspondieron a la primera generación (F1) obtenida en bioterio a partir de ejemplares adultos (n=64, ♀=28, ♂=36), originalmente recolectados en pastizales naturales cercanos a la localidad de Rafaela, provincia de Santa Fe (31°15’25.94» S - 61°29’14.48» W), en el noreste de Argentina. Cada pareja (1♂, 1♀) fue colocada en una jaula de aluminio (12x12x15cm) provista de un recipiente (sustrato) para la oviposición. Los sustratos fueron tamizados semanalmente para conocer el número promedio de posturas por hembra. Las pruebas de consumo con adultos pre-reproductivos se realizaron con ejemplares de ambos sexos recién ingresados a imagos. Luego de los once días de pruebas con adultos pre-reproductivos, todos los individuos de ambos sexos fueron reunidos por un lapso de diez días, en el cual se observaron apareamientos (cópulas). Para cada una de las pruebas de consumo se colocaron diez individuos en cada jaula de aluminio (20x20x30cm), a los cuales se les ofreció alimento. Manifestación externa de la madurez sexual en el macho (Richard & Davies 1983), se observaron a partir del quinto día de haber alcanzado el estado adulto. El tiempo promedio de incubación fue de 14.4; 1.08; (9-19) días
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
