Disponible para usuarios de ECOSUR con su clave de acceso

The competition between Cephalonomia stephanoderis and Prorops nasuta was studied in the laboratory, using coffee fruits infested with the host of these parasitoids, the coffee berry borer Hypothenemus hampei. Experiments were performed under different conditions, using: (a) three temperatures; (b) five densities of infested coffee fruits; and (c) introducing the parasitoids at different times. The effect of competition was determined according to the production of the progeny. When cultured together at the same time, C. stephanoderis produced in general, more progeny than P. nasuta under conditions of 29°C and alternating temperatures of 18-29°C. Nevertheless, there were significant differences at densities of 1 : 3, fruits : parasitoids (F0.05=8.9; d.f.=1, 12; P < 0.05) and 1 : 5 (F0.05=7.56; d.f.=1, 12; P < 0.05) at 29°C. Under alternating temperatures, there were differences at the same ratios as above in favour of C. stephanoderis, 1 : 3 (F0.05=20.08; d.f.=1, 12; P < 0.05) and 1 : 5 (F0.05=20.21; d.f.=1, 12; P < 0.05). Prorops nasuta was clearly more successful in all densities at 18°C. When C. stephanoderis was introduced 10 days before P. nasuta, the progeny production was markedly higher in eight from 10 densities at temperatures of 29°C and 18-29°C. Despite being introduced 10 days later, P. nasuta showed better performance at 18°C. When P. nasuta was introduced 10 days earlier than C. stephanoderis, there were significant differences in progeny production in favour of P. nasuta in 13 of 15 fruit densities under the three temperatures. Both parasitoids avoided ovipositing on previously parasitized hosts. Aggressive behaviour or interference was not observed when they were outside coffee fruits. Inglés

Disponible en línea

Adobe Acrobat profesional 6.0 o superior