Pilkington L.J.,University of California at Riverside |
Pilkington L.J.,Central Coast Primary Industries Center |
Lewis M.,University of California at Riverside |
Jeske D.,University of California at Riverside |
Hoddle M.S.,University of California at Riverside
Annals of the Entomological Society of America | Year: 2014
The reproductive and developmental biology, including life tables, for Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae), the glassy-winged sharpshooter, were quantified at four constant temperatures in the laboratory: 20, 25, 30, and 33°C. Mean time from egg oviposition to adult death and mean female adult longevity was greatest at 25°C. Mean total progeny production was greatest at 25°C at 214 eggs per individual. The percentage of females ovipositing at each experimental temperature was relatively low at 22, 46, and 56% at 20, 25, and 30°C, respectively. No oviposition occurred at 33°C. Upper, lower, and optimal developmental thresholds were calculated for all life stages, and for egg to adult emergence these were 35.95, 13.99, and 29.45°C, respectively. Key demographic parameters were calculated and intrinsic rate of increase and net reproductive rate were highest at 30 and 25°Cat 0.04 and 40.21 d, respectively.Meangeneration times and population doubling times were lowest at 25 (97.66 d) and 30°C (15.51 d). Modeling of demographic parameters indicated that approximately three generations of H. vitripennis per year are needed for the existence of permanent populations. Historical weather data were used to map the number of generations and estimate net reproductive rates for H. vitripennis throughout California. Data presented here will be useful for modeling and estimating the possible invasion success of H. vitripennis in areas other than California. © 2014 Entomological Society of America.
Parks S.E.,Central Coast Primary Industries Center |
Murray C.T.,Central Coast Primary Industries Center |
Gale D.L.,Central Coast Primary Industries Center |
Gale D.L.,Graham Center for Agricultural Innovation |
And 2 more authors.
Experimental Agriculture | Year: 2013
Greater cultivation of the underutilised Gac fruit, Momordica cochinchinensis, by poorly resourced householders and farmers would potentially improve livelihoods, and, on a larger scale, meet the increasing demand for Gac as a health product. Cultivation methods need to be developed to suit small- and large-scale production and must consider the unpredictable ratio of male to female plants grown from seed, and slow growth induced by cool temperatures. In this study, we examined the responses of Gac to propagation and protected cropping techniques to identify potential methods for increasing production. Plants germinated from seed in seed-raising mix under warm and humid conditions were grown hydroponically to maturity in a climate-controlled greenhouse during a temperate winter, producing fruits that were harvested ripe, from 44 weeks after sowing. Cuttings taken from female plants were dipped in indole-3-butyric rooting hormone powder or gel, or were left untreated, and then placed in rock wool, potting mix, water or closed media sachet. All treatment combinations, with the exception of the untreated potting mix, permitted the development of healthy plants in a second greenhouse crop. Growing plants from seed, then vegetatively increasing the number of productive female plants by cuttings is a means to increase Gac production with limited resources. Gac production using greenhouse technology, as described here for the first time, is relevant to other temperate regions. The finding that larger fruits have a higher percentage of edible aril than smaller fruits provides a new area of investigation towards enhancing production. Copyright © 2012 Cambridge University Press.