The development, reproduction, and life history of Encarsia citrina Craw were studied in the laboratory on San Jose scale, Quadraspidiotus perniciosus (Comstock), at constant temperatures of 15, 17.5, 20, 25, 27.5, and 30°C at 60–70% RH, and a photoperiod of 16:8 (L:D) h. Larval development did not occur at 15 and 30°C. Total developmental time varied from 22.7 d at 27.5°C to 47.4 d at 17.5°C. The lower development thresholds for larval, pupal, and egg to adult periods were 10.4, 6.3, and 9.0°C, respectively. The number of degree-days required to complete development was 434.8. The average longevity of adults ranged from 34.3 d at 15°C to 8.0 d at 30°C. The average fecundity of females ranged from 96.3 eggs at 20°C to 40 eggs at 17.5°C. Life table parameters were also determined at four constant temperatures (17.5–27.5°C). The intrinsic rate of increase, rm, values for E. citrina ranged from 0.074 at 17.5°C to 0.176 at 27.5°C. The highest net reproductive rate, R0, of 93.7 female offspring/female was estimated at 20°C. The mean generation time, T, ranged from 49.3 d at 17.5°C to 23.4 d at 27.5°C. The results of this study emphasize E. citrina survival and population growth under varied temperature conditions.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.