Résumé
The African coffee white stem borer Monochamus leuconotus (Pascoe) (Coleoptera: Cerambycidae) is a destructive insect pest of Arabica coffee trees in African highlands. Our study aims to provide information on the pest biology as influenced by temperature, determine thermal thresholds, and provide life table parameters for M. leuconotus reared in the laboratory. The life cycle of M. leuconotus was studied at seven constant temperatures in the range 15-35 degrees C, with 80 +/- 5% RH and a photoperiod of L:D 12:12. Linear and nonlinear models were fitted to laboratory data to describe the impact of temperature on M. leuconotus development, mortality, fecundity and senescence. The complete life cycle was obtained between 18 and 30 degrees C, with the egg incubation period ranging 10.8-29.2 days. The development time was longest for the larva, with 194.2 days at 30 degrees C and 543.1 days at 18 degrees C. The minimum temperature threshold (T-min) was estimated at 10.7, 10.0 and 11.5 degrees C, for egg, larva and pupa, respectively. The maximum temperature threshold (T-max) was estimated at 37.4, 40.6 and 40.0 degrees C for egg, larva and pupa, respectively. The optimum temperature for immature stage survival was estimated between 23.0 and 23.9 degrees C. The highest fecundity was 97.8 eggs per female at 23 degrees C. Simulated life table parameters showed the highest net reproductive rate (R-0) of 11.8 daughters per female at 26 degrees C and maximal intrinsic rate of increase (r(m)) between 26 and 28 degrees C, with a value of 0.008. Our results will help understanding M. leuconotus biology as influenced by temperature and may be used to predict the distribution and infestation risk under climate warming for this critical coffee pest.