Development, survival and reproduction of black citrus aphid, Toxoptera aurantii (Hemiptera: Aphididae), as a function of temperature

The development, survival, and reproduction of the black citrus aphid Toxoptera aurantii (Boyer de Fonscolombe) were evaluated at ten constant temperatures (4, 7, 10, 15, 20, 25, 28, 30, 32 and 35 degrees C). Development was limited at 4 and 35 degrees C. Between 7 and 32 degrees C, developmental periods of immature stages varied from 44.2 days at 7 degrees C to 5.3 days at 28 degrees C. Overall immature development required 129.9 degree-days above 3.8 degrees C. The upper temperature thresholds of 32.3, 28.6, 29.3, 27.2, and 28.6 degrees C were determined from a non-linear biophysical model for the development of instars 1-4 and overall immature stages, respectively. Immature survivorship varied from 82.1 to 97.7% within the temperature range of 10-30 degrees C. However, immature survivorship was reduced to 26.3% at 7 degrees C and 33.1% at 32 degrees C. Mean adult longevity was the longest (44.2 days) at 15 degrees C and the shortest (6.2 days) at 32 degrees C. The predicted upper temperature limit for adult survivorship was at 32.3 degrees C. Total nymph production increased from 16.3 nymphs per female at 10 degrees C to 58.7 nymphs per female at 20 degrees C, declining to 6.1 nymphs per female at 32 degrees C. The estimation of lower and upper temperature limits for reproduction was at 8.2 and 32.5 degrees C, respectively. The population reared at 28 degrees C had the highest intrinsic rate of increase (0.394), the shortest population doubling time (1.8 days), and shortest mean generation time (9.5 days) compared with the populations reared at six other temperatures. The population reared at 20 degrees C had the highest net reproductive rate (54.6). The theoretical lower and upper temperature limits for population development, survival and reproduction were estimated at 9.4 and 30.4 degrees C, respectively. The biology of T. aurantii was also compared with three other citrus aphid species.