Life-Fertility Tables for Frankliniella fusca (Hinds) and F. occidentals (Pergande) (Thysanoptera: Thripidae) on Peanut

Abstract

The survival, reproduction, and development of Frankliniella fusca (Hinds) and F. occidentalis (Pergande) were characterized on peanut, Arachis hypogaea L., var. Florunner, at 20, 25, 30, and 35°C and 20, 25, and 30°C, respectively. An inverse relationship exists between developmental time and temperature for F. fusca as is typical of insects; egg-to-adult duration decreased from 24 d at 20°C to 11 d at 35°C. Developmental rate of F. fusca regressed against temperature fit a linear model ( r 2 = 0.86) for total development. Developmental time for F. occidentalis was also temperature dependent as egg-to-adult duration decreased from 19 d at 20°C to 14 d at 25°C. F. occidentalis did not develop at 30°C. The lower developmental threshold estimated for F. fusca was 10.5°C and 6.5°C for F. occidentalis . Adult longevity was reduced with increasing temperatures; however, fertility remained relatively constant for both Frankliniella species as temperatures increased. F. fusca females produced an average of 14 eggs at 20, 25, and 35°C, which was less than the average produced at 30°C (24 eggs). By contrast, F. occidentalis females produced only 8–9 offspring at 20 and 25°C on peanut. Mortality for F. fusca at the extreme temperatures (20 and 35°C) and the middle temperatures (25 and 30°C) was different. Population reproductive statistics, net reproductive rate ( Ro ), generation time ( Tc ), and capacity for increase ( rc ) were estimated from the life-fertility tables for both Frankliniella species at each temperature. The capacity for increase peaked at 30°C for F. fusca ( rc = 0.16), whereas the capacity for increase was quite poor for F. occidentalis on peanut at all temperatures, 20 and 25°C ( rc = 0.02) and 30°C ( rc = 0).