Abstract

The life history parameters were studied for a western isolate of Bactericera cockerelli(Sulc) from a southern Arizona commercial tomato greenhouse (AZ - 06) during 2006. Life history parameters were determined at 26 - 27°C and 60 - 70% humidity, with a 12:12 day/night cycle. The mean pre-mating period was 4.2 days, with a range of 3.8 – 5 days, and the mean pre-oviposition period was 6.9, with a range of 5.9 – 8.0 days.The mean incubation period for the egg stage was 6.7 days (range 5.7 - 8.2 days), with a nymphal period of 21.9 (19.1 - 23.8 days). The total developmental period was 25 to 33 days, with an average of 28.4 days. The survival of eggs, nymphal stage and total (all stages) survival was 62.7, 47.3 and 40.6%, respectively. The complete life cycle at 26 - 27°C required 34.7 days, ranging from 29.9 to 37 days. Female’s fecundity was 231.8 eggs per female, with a range of 184. The longevity for single females and males when reared separately from one another was 48.7 and 22.0 days. In contrast, when males and females were reared together on the same leaf they lived for the same number of days (41.5 days), irrespective of sex. It is not clear if the discrepancies noted here in life history traits are due to genetically inherited differences among different psyllid isolates, as they could as readily be modulated by environment and/or even their histories of host plant association. Also, an additional possibility by which differences in fitness observed herein, compared to psyllid isolates studied previously (for which no voucher specimens are available), might be due to infection by some prokaryotes like Wolbachia, which already reported in literature that might influenced host fitness, e.g. fecundity and longevity.

Key words: Bactericera, fecundity, longevity, life cycle, tomato pest.