The effect of chrysanthemum leaf trichome density and prey spatial distribution on predation of Tetranychus urticae (Acari: Tetranychidae) by Phytoseiulus persimilis (Acari: Phytoseiidae)

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.


2017 ◽  
Vol 149 (5) ◽  
pp. 581-591
Author(s):  
Mona Moghadasi ◽  
Hossein Allahyari

AbstractIntraguild predation is a notable factor to proper application of biocontrol agents to reduce pest populations. Intraguild predation was studied between Typhlodromus bagdasarjani Wainstein and Arutunjan (Acari: Phytoseiidae) and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) in presence and absence of Tetranychus urticae Koch (Acari: Tetranychidae) as well as pollen. Intraguild predation between two predators was bidirectional. The highest and the lowest predation rates of both predators in absence and presence of T. urticae as well as in the pollen treatments were on heterospecific eggs and deutonymphs, respectively. Typhlodromus bagdasarjani consumed more heterospecific eggs compared with P. persimilis. When pollen was added, predation of T. bagdasarjani significantly reduced on heterospecific eggs and deutonymphs in absence and presence of T. urticae treatments, respectively. However, predation rate of P. persimilis on heterospecific stages was not significantly affected by pollen addition. Oviposition of both predators was higher in presence of T. urticae than in its absence and oviposition of P. persimilis was significantly higher on heterospecific stages than T. bagdasarjani. Pollen addition had a significant effect on increasing the oviposition rate of T. bagdasarjani. Extraguild prey presence had a nonsignificant effect on the consumption rate of intraguild prey by the intraguild predators. However, presence of extraguild prey led to a significant increase in oviposition rate of both predators.



2017 ◽  
Vol 22 (10) ◽  
pp. 1698 ◽  
Author(s):  
Sahar Saemi ◽  
Hasan Rahmani ◽  
Aurang Kavosi ◽  
Hsin Chi

To better understand the effect of individual- and group-rearing conditions on predator performance, we studied the life table and predation rate of the predatory mite, Phytoseiulus persimilis Athias-Henriot, after the mites had been individually- or group-reared on two-spotted spider mites, Tetranychus urticae, eggs at 25±1°C, 65±5% RH and a photoperiod of 16: 8 (L:D) h. The net reproductive rate (R0), intrinsic rate of increase (r), net predation rate (C0), finite predation rate (ω) in the individually-reared predators were 40.61 offspring, 0.2594 d-1, 437.3 T. urticae eggs, and 4.8668 preys/d, respectively. Similar values were obtained when the predators were reared in groups (R0 = 43.10 offspring, r = 0.2837 d-1, C0 = 420.9 T. urticae eggs, and ω = 5.9054 preys/d). Mean adult longevities were 28.42 and 25.29 d for group-reared male and female predators, respectively; these values were significantly shorter than those of individual-reared mites (49.87 d for male and 36 d for female). Our results showed that P. persimilis mites could be group-reared in biological control programs without negative effect on their growth and predation potential. 



Acarologia ◽  
2019 ◽  
Vol 59 (3) ◽  
pp. 301-307
Author(s):  
Alain Migeon ◽  
Marie-Stéphane Tixier ◽  
Maria Navajas ◽  
Vassilis D. Litskas ◽  
Menelaos C. Stavrinides

The predator-prey system Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) and Tetranychus urticae (Koch) (Acari: Tetranychidae) represents the most studied and the most known system among the Acari. Because of the agronomical importance of the two mite species, a wealth of modelling studies investigated the interactions of the two species at the individual level. However, regional or global level works on this system are lacking, which is impeding the investigation of climate change effects on biological control effectiveness. Here we compile and geo-locate worldwide occurrences for the two species considered, based on literature, collection and field survey data. The datasets presented in this document gather most of the literature records of both species for which locality data were available for geo-referencing (1,037 for T. urticae and 126 for P. persimilis). Geo-located data from collections and field surveys including host-plants are also presented for the first time (322 for T. urticae and 65 for P. persimilis). Phytoseiulus persimilis is also reported for the first time from Kenya and La Martinique.



Genetics ◽  
1998 ◽  
Vol 149 (2) ◽  
pp. 565-577
Author(s):  
Daniel B Szymanski ◽  
Daniel A Klis ◽  
John C Larkin ◽  
M David Marks

Abstract In Arabidopsis, the timing and spatial arrangement of trichome initiation is tightly regulated and requires the activity of the GLABROUS1 (GL1) gene. The COTYLEDON TRICHOME 1 (COT1) gene affects trichome initiation during late stages of leaf development and is described in this article. In the wild-type background, cot1 has no observable effect on trichome initiation. GL1 overexpression in wild-type plants leads to a modest number of ectopic trichomes and to a decrease in trichome number on the adaxial leaf surface. The cot1 mutation enhances GL1-overexpression-dependent ectopic trichome formation and also induces increased leaf trichome initiation. The expressivity of the cot1 phenotype is sensitive to cot1 and 35S::GL1 gene dosage, and the most severe phenotypes are observed when cot1 and 35S::GL1 are homozygous. The COT1 locus is located on chromosome 2 15.3 cM north of er. Analysis of the interaction between cot1, try, and 35S::GL1 suggests that COT1 is part of a complex signal transduction pathway that regulates GL1-dependent adoption of the trichome cell fate.



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



2020 ◽  
Vol 113 (4) ◽  
pp. 1735-1740
Author(s):  
Md Arefur Rahman ◽  
Souvic Sarker ◽  
Eunhye Ham ◽  
Jun-Seok Lee ◽  
Un Taek Lim

Abstract The polyphagous predator Orius species is a dominant predator of thrips, mites, and aphids. Orius laevigatus (Fieber) is a well-known commercialized and effective biological control agent, whereas Orius minutus (L.) distributed widely over the world has not been commercialized. To assess potentials of developing O. minutus as a commercial biological control agent, we compared the biological parameters of O. minutus with O. laevigatus when reared on mixed stages of Tetranychus urticae Koch at 27.5°C. Nymphal development of O. laevigatus was shorter (11.30 d) than that of O. minutus (12.25 d), but there was no significant difference in survivorship between the two species. Also, no significant difference was found in either the preoviposition or oviposition periods, lifetime fecundity, or longevity between the two species. However, O. minutus eggs had a higher hatch rate (0.77) than O. laevigatus (0.71). In life table analysis, no difference was found in any parameters, i.e., R0, rm, λ, T, and DT, between O. laevigatus and O. minutus in two-tailed t-tests. In a predation bioassay, O. minutus consumed 1.39 times more adult T. urticae in 24 h than did O. laevigatus, although the predation rate on T. urticae eggs was similar between the two species. These results suggest that O. minutus native to Korea could be developed as a biological control agent against T. urticae.



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