Co-Authors:
Nestel, D., Department of Entomology, Institute of Plant Protection, Volcani Center, P.O. Box 6, 50250 Beit-Dagan, Israel
Nemny-Lavy, E., Department of Entomology, Institute of Plant Protection, Volcani Center, P.O. Box 6, 50250 Beit-Dagan, Israel
Alchanatis, V., Department of Sensing, Information and Mechanization, Institute of Agricultural Engineering, Volcani Center, P.O. Box 6, 50250 Beit-Dagan, Israel
Abstract:
The pattern of gas-exchange (CO2 emission) was investigated for developing Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) pupae incubated at different temperatures. This study was undertaken to explore the usefulness of gas-exchange systems in the determination of physiological age in developing pupae that are mass produced for sterile insect technique projects. The rate of CO2 emission was measured in a closed flow-through system connected to commercial infrared gas analysis equipment. Metabolic activity (rate of CO2 emission) was related to pupal eye-color, which is the current technique used to determine physiological age. Eye-color was characterized digitally with 3 variables (Hue, Saturation and Intensity), and color separated by discriminant analysis. The rate of CO2 emission throughout pupal development followed a U-shape, with high levels of emission during pupariation, pupal transformation and final pharate adult stages. Temperature affected the development time of pupae, but not the basic CO 2 emission patterns during development. In all temperatures, rates of CO2 emission 1 and 2 d before adult emergence were very similar. After mid larval-adult transition (e.g., phanerocephalic pupa), digital eye-color was signifi-cantly correlated with CO2 emission. Results support the suggestion that gas-exchange should be explored further as a system to determine pupal physiological age in mass production of fruit flies.