Effects of different planting dates on improving yield of Fritillaria imperialis L. and Fritillaria persica L. bulbs damaged by small narcissus fly (Eumerus strigatus Fallen)

Fritillaria imperialis and F. persica were planted during April 2003 and May 2004 growing seasons on the basis of split block design with three replications to investigate the effects of planting dates on various plant parameters and extent of recovery by planting 25% damaged bulbs. The results showed significant effects of planting dates on plant height, number of bulbs per plant and infected bulb ratio. A comparison of the two species showed that F. persica gave more bulblets than F. imperialis. A generalcomparison of the two species also showed that damaged bulbs of F. imperialis produced lesser yield compared to F. persica. Furthermore, both species gave more number of bulblets from early and mid September plantings compared to early and mid October plantings. The most suitable date of planting was determined as September 1st and 15th

Effect of certain Brassica plants on biology of the cabbage aphid Brevicoryne brassicae under laboratory conditions

The development time, mortality, survivorship and reproduction of the cabbage aphid Brevicoryne brassicae (L.) were evaluated on detached leaves of six Brassica species (cabbage cv. 'Yalova 1', cauliflower cv. 'Early Snowball', broccoli cv. 'Marathon', turnip cv. 'Antep', rapeseed cv. local variety, and wild mustard) at a constant temperature of 200C. Total development time of B. brassicae was the shortest (8.9 days) on cauliflower and the longest (10.4 days) on cabbage. Mortality of immature stages varied from 16% on cabbage to 88% on turnip. Longevity of the cabbage aphid was the shortest (6.2 days) on mustard, and the longest (21.8 days) on cauliflower. The net reproductive rate was highest (35.98) on cauliflower, and lowest (1.89) on turnip. The intrinsic rate of increase was 0.2345 on cauliflower, followed by 0.2009 on cabbage, 0.1976 on broccoli, 0.1662 on mustard, 0.1357 on rapeseed, and 0.0465 on turnip. Cabbage, cauliflower and broccoli were susceptible host plants for the cabbage aphid. Rapeseed, turnip and mustard showed resistance to the pest.This research, project TOGTAG-2973, was supported by the Scientific and Technical Research Council of Turkey (T~IBITAK)a nd the Research Fund of (~ukurova University, Turkey

Effect of temperature on the biology of Aphis punicae (Passerini) (Homoptera: Aphididae) on Pomegranate

The effect of temperature on development time, reproductive capacity, and rate of survival for Aphis punicae was studied at five different (constant) temperatures (17.5, 20, 22.5, 25, and 27.5°C). The development period for immature instar stages ranged from 11.72 d at 17.5°C to 4.30 d at 27.5°C. The lowest developmental threshold was 11.8°C, and the thermal constant (K) was 66.4 DD. The percentage survivorship of immature stages varied from 72.0 to 90.0% over a temperature range of 17.5-27.5°C. The average longevity of adult females was 16.50, 17.17, 18.16, 12.04, and 8.91 d at temperatures of 17.5, 20, 22.5, 25, and 27.5°C, respectively. The average number of offspring produced by a single female was 14.65, 22.68, 31.34, 21.31, and 11.27 at temperatures of 17.5, 20, 22.5, 25, and 27.5°C, respectively. The greatest rm (0.3292) was observed at 25°C. The optimal temperature for A. punicae growth, development, and reproduction was 22.5-25°C

Effect of different temperatures on the biological parameters of Macrosiphum rosae (L.) (Homoptera: Aphididae)

The development, survivorship, and reproduction of rose aphid, Macrosiphum rosae (L.), were evaluated at four constant temperatures (17.5, 20, 22.5, and 25°C). The developmental periods of immature stages ranged from 10.7 d at 17.5°C to 7.95 d at 25°C. The total percentages of survivorship of immature stages varied from 52.06 and 86% within the temperature range of 17.5-25°C. However, the total percentages of survivorships were reduced to 52.06 and 54% at 17.5 and 25, respectively. The average longevity of adult females was 13.92, 10.74, 18.55, and 8.65 d at 17.5, 20, 22.5, and 25°C, respectively. The average progeny per female was 19.75, 13.28, 34.92, and 7.23 at 17.5, 20, 22.5, and 25°C, respectively. The largest rm (0.170865) occurred at 22.5°C. The optimal temperature for M. rosae population growth was 22.5°C

Effect of temperature on development, mortality, fecundity, and reproduction of Aphis rumicis L. (Homoptera: Aphididae) on broadleaf dock (Rumex obtusifolius) and Swiss chard (Beta vulgaris vulgaris var. cida)

Temperature effects on developmental period, survival rate, and reproductive capacity of Aphis rumicis L. were studied on Broadleaf dock and Swiss chard at four constant temperatures (17.5°C, 20°C, 22.5°C, and 25°C). The developmental time of immature stages ranged from 10.9 days at 17.5°C to 6.5 days at 25°C on Broadleaf dock, and 11.8 days at 17.5°C to 6.5 days at 25°C on Swiss chard. The total percentage of survivorship of immature stages varied from 54.2% and 67.6% 17.5°C-25°C on Broadleaf dock, and 49.7% and 62.4% at 17.5°C-25°C on Swiss chard. The largest rm value occurred with 0.2845 at 25°C on Broadleaf dock and with 0.2785 at 25°C on Swiss chard. The results obtained on this study indicated that Swiss chard was a less favorable host of the A. rumicis than Broadleaf dock. The optimal temperature for A. rumicis growth, developmental time, and reproduction was 22.5°C-25°C. © Springer-Verlag 2005