The effects of different temperatures (26, 28, 30, and 32°C) and CO2 concentrations (380 and 550 ppm) on the life table of Tuta absoluta were evaluated. The life history raw data of T. absoluta were analyzed by using the age-stage, two-sex life table. Results showed that increase in temperature reduced the larval developmental time of T. absoluta, whereas the elevated CO2 concentration (eCO2) extended the larval developmental time. Highest fecundity rate was recorded at 30°C at ambient CO2 (aCO2) condition (88.10 eggs). Total fecundity significantly reduced under eCO2 at 28°C and 30°C. There was a 5-10% higher mortality observed under eCO2 than aCO2 condition. With rise in temperature from 26-30°C, T. absoluta reared under eCO2 condition showed lower net reproductive rate, intrinsic and finite rate of increase in comparison to aCO2. However, these parameters started decreasing at 32°C under both eCO2 and aCO2 conditions.

The influence of host plant on population dynamics of an invasive pest, Tuta absoluta was studied on three economically important solanaceous crops. Experiments were conducted in laboratory (29 ± 0.5°C, 75 ± 5% RH and a photoperiod of 14:10 hr [L:D]) using tomato (Solanum lycopersicum L.), potato (Solanum tuberosum L.) and eggplant (Solanum melongena L.). Results indicated that intrinsic rate of increase (r), finite rate of increase (λ) and net reproductive rate (R0) were higher, and mean generation time (T) was the shortest on tomato. Results suggested that T. absoluta developed on all the three plants, and tomato plant was most preferred one. Results suggested that T. absoluta has a potential to become a serious pest on potato and even on eggplant under favourable conditions. We used the life tables of 0.025th and 0.975th percentiles of bootstraps to project the uncertainty of population growth, a new concept.

The cycad aulacaspis scale, Aulacaspis yasumatsui Takagi (Hemiptera: Coccoidea: Diaspididae), is native to Southeast Asia but an invasive pest of the gymnosperm order Cycadales in many parts of the world. Aulacaspis yasumatsui was recently reported on the cycad genus Encephalartos in South Africa and is currently categorized as a ‘prohibited terrestrial invertebrate’ in the invasive species legislation, National Environmental Management: Biodiversity Act, 2004 (NEM:BA). Encephalartos is endemic to Africa, and 11 species are listed as critically endangered and four species as endangered. Seeing the limited distribution of A. yasumatsui in South Africa and only one unconfirmed record from the Ivory Coast, understanding the potential distribution range is essential for control and management. Here we model the potential distribution of A. yasumatsui under current and future climate scenarios in Africa, with a focus on South Africa. Future climatic scenarios were simulated using a bio-climatic software, CLIMEX. The model indicates that, under the current climatic scenario, all 17 African countries possessing Encephalartos are susceptible to A. yasumatsui establishment. However, under climatic change, the suitability decreases for large parts of Africa. In South Africa, 93% of the winter rainfall areas, and 90% of the temperate, summer rainfall areas are suitable for A. yasumatsui establishment. In this study, we highlight the urgent need for regulation, management, and research on A. yasumatsui in African countries with native cycads.