The poinsettia strain of the cotton whitefly,Bemisia tabaci(Homoptera: Aleyrodidae), biological and demographic parameters on poinsettia (Euphorbia pulcherrima) in relation to temperature

Publisher Website
Google Scholar
Abstract
Biological characteristics of the poinsettia strain ofBemisia tabaciGennadius were investigated on poinsettia by laboratory experiments at five temperatures (range: 16°C–28°C). In addition, the effect of rearingB. tabacion the two plant species,Nicotiana tabacum(tobacco) (Solanaceae) andEuphorbia pulcherrima(Euphorbiaceae) (poinsettia) was investigated. The temperature-dependencies were established for the developmental time for eggs and egg-to-adult phase, juvenile mortality, adult female life-span, pre-oviposition period, age-specific fecundity, and sex-ratio. The lower temperature thresholds for egg-development, development from egg to adult and for ovipositional adults were estimated as well as the lower temperature threshold for oviposition. The thresholds were 12°C, 14°C, 8°C and 14°C, respectively. Egg-development required 126 day-degrees and the entire development into adults 327 day-degrees. Mortality was highest at 16°C, being 19.3% in the egg-stage and 95% from egg to adult. The pre-oviposition period and the adult life-span were 40 and 360 day-degrees. The age-specific fecundity ofB. tabaciwas described by a temperature-dependent model. The maximum daily fecundity rate was attained after 60 and 125 day-degrees forB. tabacireared on tobacco and poinsettia, respectively. The fecundity was highest forB. tabacireared on poinsettia. The sex-ratio was in favour of females at and above 19°C and increased with temperature. Estimates of the net reproductive rate, the intrinsic rate of increase, the finite rate of increase, the mean generation time and the doubling time were obtained. A positive linear relationship was found between rmand temperature, the values ranging from 0.0012 at 16°C to 0.1263 at 28°C.