Leaf pubescence and two-spotted spider mite webbing influence phytoseiid behavior and population density

In this study, population density and yield loss caused by two-spotted spider mite (TSSM) on eight lines of pinto bean were studied under field conditions during two successive years (2009-2010). The experiment was arranged in completely randomized block design with subdivided plots and four replications in Lordegan fields, Chaharmahal va Bakhtiari province, Iran. The main plots and sub-plots consisted of bean lines and acaricides application, respectively. Population density of TSSM was recorded at weekly intervals, beginning from the seedling stage and continued to harvesting time on different lines. Yield loss caused by the mite on each line, was calculated by subtracting the average yields in sprayed subplots versus unsprayed subplots. For this purpose, 10 plants from each subplot were selected randomly and the yield and yield components including; the number of pods/plant, number of seeds/pod and weight of 100 seeds were recorded. Moreover, the grain yield (kg. ha-1) was determined by harvesting the central area (10 m2) in each subplot. Our results indicated significant differences in TSSM population (eggs, juveniles and adults) among the studied lines. In 2009, the highest number of mite was recorded on line ‘L29’ (120.20 ± 18.79) whereas, the lowest on line ‘L1’ (22.51 ± 4.96 mites/ 2 cm2 of the abaxial leaf surface). Moreover, during 2010, the highest and the lowest population density of the mite were supported by line ‘D3’ (55.53 ± 5.68) and line ‘L1’ (9.33 ± 0.79 mites/ 2 cm2 of the abaxial leaf surface), respectively. Mean yield loss of pinto bean lines due to the mite attack calculated 1460.6 kg. ha-1 (64.1 ± 10.2%) and 1278.7 kg. ha-1 (61.4 ± 8.6%) in 2009 and 2010, respectively. The highest grain yield loss presented by line ‘L1’ (91.1 ± 12.1% and 86.4 ± 8.9%) followed by lines ‘L29’and ‘L30’, whereas, the lowest observed in lines ‘J29’ (41.5 ± 7.7% and 37.5 ± 7.6%) and ‘L19’ (50.7 ± 6.6% and 47.4 ± 5.4% in 2009 and 2010, respectively).

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Gradients in Susceptibility and Resistance Mechanisms of Buddleia L. Taxa to the Two-spotted Spider Mite (Tetranychus urticae Koch)

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.124.2.114 ◽

1999 ◽

Vol 124 (2) ◽

pp. 114-121 ◽

Cited By ~ 3

Author(s):

Jeffrey H. Gillman ◽

Michael A. Dirr ◽

S. Kristine Braman

Keyword(s):

Surface Area ◽

Spider Mite ◽

Methylene Chloride ◽

Leaf Surface ◽

Spider Mites ◽

Leaf Pubescence ◽

Shell Vial ◽

Methylene Chloride Extract ◽

Leaf Surface Area ◽

Two Spotted Spider Mite

Buddleia taxa were assessed for two-spotted spider mite (Tetranychus urticae Koch) resistance using a leaf disk bioassay, a novel shell vial bioassay and a field trial. Leaf pubescence and chemistry were examined for their role in two-spotted spider mite resistance. Results from bioassays and field sampling identified highly resistant taxa including B. fallowiana Balif. `Alba' and B. davidii × B. fallowiana Franch. `Cornwall Blue' as well as susceptible taxa including B. davidii Franch. `African Queen' and B. lindleyana Fort. ex Lindl. `Gloster'. The shell vial bioassay was an accurate predictor of field resistance to spider mite. Leaf pubescence was quantified by calculating the collective length of trichome branches per square millimeter of leaf surface area [effective branch length (EBL)]. EBL values ranged from 39 to 162 mm·mm-2 of leaf surface area among Buddleia taxa. Resistance was positively correlated with increased pubescence. Removal of pubescence by peeling resulted in increased oviposition of two-spotted spider mites. Exposing female two-spotted spider mites to a methylene chloride extract of B. davidii × B. fallowiana `Cornwall Blue' using a modified shell vial bioassay resulted in reduced oviposition and a methylene chloride extract of B. davidii `African Queen' resulted in no difference in oviposition when compared with a control. While pubescence is the best indicator of resistance to the two-spotted spider mite in Buddleia taxa, it is possible that defensive compounds are involved.

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Factors Affecting the Resistance of Buddleia Species to the Two-Spotted Spider Mite

HortScience ◽

10.21273/hortsci.32.4.595a ◽

1997 ◽

Vol 32 (4) ◽

pp. 595A-595

Author(s):

Jeff Gillman ◽

Michael Dirr ◽

Kristine Braman

Keyword(s):

Drought Stress ◽

Spider Mite ◽

Block Design ◽

Spider Mites ◽

Leaf Pubescence ◽

Shell Vial ◽

Factors Affecting ◽

Randomized Block Design ◽

Two Factors ◽

Two Spotted Spider Mite

Buddleia species are attractive ornamental shrubs whose major cultural problem is infestations of the two-spotted spider mite. Two factors, drought stress and leaf pubescence, were examined for their effects on spider mite infestations. Drought stress was examined by placing 20 plants into a randomized block design and stressing ten of the plants. No differences in mite life parameters were found, although there was more uninfested area in nonstressed plants. This was probably due to the nonstressed plants' ability to outgrow the spider mite infestation. Leaf texture was examined by placing four female spider mites on 5 leaf disks of 37 cultivars and species of Buddleia and counting the number of eggs laid after 96 hours. There was a strong correlation between leaf pubescence and number of eggs laid. In a second experiment, using a shell vial with a leaf placed underneath the lid and five female spider mites in the vial itself, leaf pubescence was either removed with facial peel or left. In all cases but one, the removal of pubescence increased the number of eggs laid by the spider mites.

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Influence of leaf pubescence on the behavior of the two-spotted spider mite (Tetranychus urticae) and the European red mite (Panonychus ulmi)

Acta Agrobotanica ◽

10.5586/aa.2003.011 ◽

2013 ◽

Vol 56 (1-2) ◽

pp. 109-115 ◽

Cited By ~ 1

Author(s):

Wojciech Warabieda ◽

Mike Solomon

Keyword(s):

Tetranychus Urticae ◽

Spider Mite ◽

Mite Species ◽

Panonychus Ulmi ◽

Movement Behavior ◽

Quick Method ◽

Leaf Pubescence ◽

European Red Mite ◽

Stop Time ◽

Two Spotted Spider Mite

Movement behavior of two mite species: two-spotted spider mite (Tetranychus urticae) and European red mite (Panonychus ulmi) on leaves of some apple cultivars (´Greensleeves´, ´Spartan' and SA 455-2 selection) with different density of pubescence was analysed. Assessment of the leaf pubescence density was performed using an originally developed quick method based on digital pubescence mage analysis. For P.ulmi, both stop time and average speed did not depend on kind of leaf. In contrary. T.urticae revealed higher movement activity on slight pubescent leaves compared to leaves with high leaf hair density.

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