The Pesticide Tolerance of Typhlodromus fallacis (Garman) and Phytoseiulus persimilis A. H. with Some Observations on the Predator Efficiency of P. persimilis

1963 ◽  
Vol 56 (3) ◽  
pp. 274-278 ◽  
Author(s):  
Floyd F. Smith ◽  
T. J. Henneberry ◽  
A. L. Boswell
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kazuki Togashi ◽  
Mifumi Goto ◽  
Hojun Rim ◽  
Sayaka Hattori ◽  
Rika Ozawa ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gamze Incedayi ◽  
Harun Cimen ◽  
Derya Ulug ◽  
Mustapha Touray ◽  
Edna Bode ◽  
...  

AbstractOur study aimed to identify the novel acaricidal compound in Xenorhabdus szentirmaii and X. nematophila using the easyPACId approach (easy Promoter Activated Compound Identification). We determined the (1) effects of cell-free supernatant (CFS) obtained from mutant strains against T. urticae females, (2) CFS of the acaricidal bioactive strain of X. nematophila (pCEP_kan_XNC1_1711) against different biological stages of T. urticae, and females of predatory mites, Phytoseiulus persimilis and Neoseiulus californicus, (3) effects of the extracted acaricidal compound on different biological stages of T. urticae, and (4) cytotoxicity of the active substance. The results showed that xenocoumacin produced by X. nematophila was the bioactive acaricidal compound, whereas the acaricidal compound in X. szentirmaii was not determined. The CFS of X. nematophila (pCEP_kan_XNC1_1711) caused 100, 100, 97.3, and 98.1% mortality on larvae, protonymph, deutonymph and adult female of T. urticae at 7 dpa in petri dish experiments; and significantly reduced T. urticae population in pot experiments. However, the same CFS caused less than 36% mortality on the predatory mites at 7dpa. The mortality rates of extracted acaricidal compound (xenocoumacin) on the larva, protonymph, deutonymph and adult female of T. urticae were 100, 100, 97, 96% at 7 dpa. Cytotoxicity assay showed that IC50 value of xenocoumacin extract was 17.71 μg/ml after 48 h. The data of this study showed that xenocoumacin could potentially be used as bio-acaricide in the control of T. urticae; however, its efficacy in field experiments and its phytotoxicity need to be assessed in future.


2003 ◽  
Vol 93 (4) ◽  
pp. 343-350 ◽  
Author(s):  
M.C. Stavrinides ◽  
D.J. Skirvin

AbstractThe effect of plant architecture, in terms of leaf hairiness, and prey spatial arrangement, on predation rate of eggs of the spider mite, Tetranychus urticae Koch, by the predatory mite Phytoseiulus persimilis Athias-Henriot was examined on cut stems of chrysanthemums. Three levels of leaf hairiness (trichome density) were obtained using two different chrysanthemum cultivars and two ages within one of the cultivars. The number of prey consumed by P. persimilis was inversely related to trichome density. At low prey densities (less than ten eggs per stem), prey consumption did not differ in a biologically meaningful way between treatments. The effect of prey spatial arrangement on the predation rate of P. persimilis was also examined. Predation rates were higher in prey patches on leaves adjacent to the release point of P. persimilis, but significantly greater numbers of prey were consumed in higher density prey patches compared to low density patches. The predators exhibited non-random searching behaviour, spending more time on leaves closest to the release point. The implications of these findings for biological control and predator–prey dynamics are discussed.


1970 ◽  
Vol 16 ◽  
pp. 1-10 ◽  
Author(s):  
M Fazlul Hoque ◽  
W Islam ◽  
M Khalequzzaman

Life table of Tetranychus urticae and Phytoseiulus persimilis on bean leaflets were studied under laboratory conditions in three seasons. For T. urticae the development time from egg to adult varied from 7 to 24 days and the highest immature mortality was 78.70 % in winter. Eggs laid by females were 88.1 eggs in autumn and 70.6 eggs in summer season. The gross reproductive rate (GRR) was the highest (65.51) in autumn and 52.50 in summer. The net reproductive rate (Ro) was the highest (15.862) in autumn and 8.916 in summer. The intrinsic rates of increase (rm) and finite capacity for increase (λ) reached maximal values (0.1873 and 1.206) in autumn, whereas minimal values (0.056 and 1.058) were in winter season. The mean generation time (T) was the shortest in summer and double (3.701) days in autumn. The development time of P. persimilis from egg to adult varied from 5 to 14 days. The highest immature mortality was 60% in summer. Eggs laid by females were 39.4 eggs in autumn and 30.2 eggs in summer. The gross reproductive rate (GRR) was the highest (31.4) in autumn and 24.0 in summer. The net reproductive rate (Ro) was the highest (10.573) in autumn and 8.460 in winter. The intrinsic rates of increase (rm) and finite capacity for increase (λ) reached maximal values (0.1823 and 1.200) in summer, whereas minimal values (0.1025 and 1.108) were in winter. The mean generation time (T) was the shortest in summer. The results suggested that P. persimilis could develop and reproduce within a wide range of temperatures. Key words: Tetranychus urticae, Phytoseiulus persimilis, immature mortality, intrinsic rates of increase, reproductive rate, Survival  DOI:10.3329/jbs.v16i0.3733 J. bio-sci. 16: 1-10, 2008


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