Submitted to: Sistemas Agroecologicos y Modelos Biomatematicos
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 10, 2010
Publication Date: N/A
Interpretive Summary: The economic value of coffee worldwide is about 15 billion dollars per year. The coffee berry borer is currently the most destructive pest in coffee plantations. Two African parasitoids Cephalonomia stephanoderis and Prorops nasuta were introduced in the American Continent for its control. For more than two decades these parasitic wasps have being equally treated, because their biology are broadly similar, produced and released using the same methods for both species; however, this investigation showed that the reproductive rate and intrinsic rate of increase of C. stephanoderis were much higher, giving a better understanding why C. stephanoderis has been more successful under laboratory and field conditions. The results of this investigation were used to improve the existing rearing method of C. stephanoderis and developed a new rearing system for P. nasuta.
Technical Abstract: Biological aspects and demographic parameters of the African bethylid wasps Cephalonamia stephanoderis Betrem and Prorops nasuta Waterson (Hymenopterans: Bethylidae) were investigated using diet-reared hosts of Hypothenemus hampei Ferrari (Coleoptera: Scolytidae). The life cycle (28.40 ± SE 0.486 and 32.57 ± SE 0.5003 days), oviposition (32.13 ± SE 13.16 and 28.40 ± SE 8.42 days) and post-oviposition periods (11.00 ± SE 8.54 and 17.46 ± SE 8.58 days) were comparable among both species (C. stephanoderis and P. nasuta, respectively). However, pre-oviposition and longevity period averaging was Langer for P. nasuta (17.3 ± SE 10.57 and 63.13 ± SE 13.13 days, respectively) than it was for C. stephanoderis (4.53 ± SE 0.43 and 47.66 ± SE 15.41 days). Demographic parameters showed highly significant differences among species: The gross fecundity for C. stephanoderis was 81.99 ± SE 0.73 offspring/ female with a mean generation of 48.34 ± SE 0.23 days, whereas for P. nasuta was 37.90 ± SE 1.16 offspring/ female with a generational time of 58.38 ± SE 0.69 days. The reproductive rate and intrinsic rate of increase of C. stephanoderis were much higher (56.57 ± SE 0.7413 daughters/ female and 0.0918 ± SE 0.00034, respectively) than it was for P. nasuta (17.34 ± SE 0.5736 daughters/ female and 0.05264 ± SE 0.0010, respectively). These results were used to improve the rearing system of C. stephanoderis and developed a new rearing system for P. nasuta, which were kept for several generations at National Biological Control Laboratory in Stoneville, MS, USA.