CONICET | Buscador de Institutos y Recursos Humanos

Borellia bruneri (Rehn) is one of the most common species of Gomphocerinae of grasshopper communities inhabiting the Pampas grasslands of Argentina and one of the most harmful in the Pampas of Uruguay. It is a univoltine species with obligatory embryonic diapause and shows a wide geographic distribution, occurring in southernmost Brazil, much of Argentina, Chile, and Uruguay. B. bruneri is one of the 18 grasshopper species considered to be of actual or potential economic relevance as pests in Argentina. Several studies have been recently conducted on population dynamics of B. bruneri in the Pampas region but important aspects related to the life cycle development are still unknown. Because of this, the central objective of this study was to determine different biological and reproductive parameters of B. bruneri in the laboratory under controlled conditions.Biological and reproductive aspects of B. bruneri were estimated by monitoring three cohorts of the first generation (F1) of individuals born in captivity from grasshoppers collected in the South of Buenos Aires province, Argentina, and held under controlled conditions (30° C, 14 light ? 10 dark; 40% RH).Five nymphal instars were recorded for both females and males. Total duration of nymphal development was 50.6 ± 0.44 (47-63) days: No significant differences were registered in the duration of the nymphal cycle between different cohorts (ANOVA p>0.05). The average longevity of female adults was 56.6 ± 1.35 days, and in males it was 54.4 ± 0.98 days. There were no significant differences between longevity of males and females (p>0.05). The number of egg-pods per female was 3.5 ± 0.2 (1-5) and the amount of eggs per egg-pod was 10.8 ± 0.6 (7-14). Mean fecundity was 37.9 ± 1.8 eggs per female with an oviposition rate of 1.20 ± 0.2 eggs/female/day. The highest reproductive value of females were reached in the fourth week leaving a number of egg-pods significantly higher (p