13 research outputs found
The abundance of Orius niger (Wolf.) and O. minutus (L.) in potato fields and their life table parameters when fed on two prey species
Field efficacy of a biopesticide prepared from Clerodendrum viscosum Vent. (Verbenaceae) against two major tea pests in the sub Himalayan tea plantation of North Bengal, India
Chemical-based integrated approaches for the management of tea red spider mite, Oligonychus coffeae
Clove Oil Efficacy on the Red Spider Mite, Oligonychus coffeae Nietner (Acari: Tetranychidae) Infesting Tea Plants
Novel and versatile methodology for synthesis of β-aryl-β-mercapto ketone derivatives as potential urease inhibitors
Alternating temperatures affect life table parameters of Phytoseiulus persimilis, Neoseiulus californicus (Acari: Phytoseiidae) and their prey Tetranychus urticae (Acari: Tetranychidae)
Increasing energy costs force glasshouse growers to switch to energy saving strategies. In the temperature integration approach, considerable daily temperature variations are allowed, which not only have an important influence on plant growth but also on the development rate of arthropods in the crop. Therefore, we examined the influence of two constant temperature regimes (15 A degrees C/15 A degrees C and 20 A degrees C/20 A degrees C) and one alternating temperature regime (20 A degrees C/5 A degrees C, with an average of 15 A degrees C) on life table parameters of Phytoseiulus persimilis and Neoseiulus californicus and their target pest, the two-spotted spider mite Tetranychus urticae at a 16:8 (L:D) h photoperiod and 65 +/- A 5 % RH. For females of both predatory mites the alternating temperature regime resulted in a 25-30 % shorter developmental time as compared to the corresponding mean constant temperature regime of 15 A degrees C/15 A degrees C. The immature development of female spider mites was prolonged for 7 days at 15 A degrees C/15 A degrees C as compared to 20 A degrees C/5 A degrees C. With a daytime temperature of 20 A degrees C, no differences in lifetime fecundity were observed between a nighttime temperature of 20 and 5 A degrees C for P. persimilis and T. urticae. The two latter species did show a higher lifetime fecundity at 20 A degrees C/5 A degrees C than at 15 A degrees C/15 A degrees C, and their daily fecundity at the alternating regime was about 30 % higher than at the corresponding mean constant temperature. P. persimilis and T. urticae showed no differences in sex ratio between the three temperature regimes, whereas the proportion of N. californicus females at 15 A degrees C/15 A degrees C (54.2 %) was significantly lower than that at 20 A degrees C/5 A degrees C (69.4 %) and 20 A degrees C/20 A degrees C (67.2 %). Intrinsic rates of increase were higher at the alternating temperature than at the corresponding mean constant temperature for both pest and predators. Our results indicate that thermal responses of the studied phytoseiid predators to alternating temperature regimes used in energy saving strategies in glasshouse crops may have consequences for their efficacy in biological control programs