The preliminary assessment and isolation of entomopathogenic fungi to be used in biological control with twospotted spider mite [Tetranychus urticae (acari, tetranychidae)] from East Anatolia

AbstractThe threshold temperature of development, life table, and innate capacity for increase of the twospotted spider mite, Tetranychus urticae Koch, were established from life stage development studies at constant temperatures. The threshold for development was determined to be 10.0°C. The durations in degree-days above 10°C from the beginning of the egg stage to adult for females were 141.3, 152.3, and 139.8; for males 134.2, 144.7, and 135.2 at 15°, 18°, and 21°C, respectively. Life tables were constructed and innate capacity for increase was .069, .156, and .372; net reproduction rate 20.8, 38.4, and 58.1; and mean generation time 44.0, 23.4, and 10.9 at 15°, 18°, and 21°C, respectively.

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Oviposition Response of Tetranychus urticae (Acari: Tetranychidae) to Direct Treatment and Residue of Pyrethroids on Soybean

Journal of Entomological Science ◽

10.18474/0749-8004-25.1.158 ◽

1990 ◽

Vol 25 (1) ◽

pp. 158-169 ◽

Cited By ~ 4

Author(s):

D. J. Donahue ◽

R. M. McPherson

Keyword(s):

Tetranychus Urticae ◽

Spider Mite ◽

Leaf Surface ◽

Oviposition Rate ◽

Twospotted Spider Mite ◽

Direct Treatment ◽

Dosage Rate ◽

Direct Exposure ◽

Tetranychus Urticae Koch ◽

Twospotted Spider

The oviposition response of the twospotted spider mite (TSSM), Tetranychus urticae Koch, to direct treatment and residues of fenvalerate and permethrin on soybean was examined in the laboratory. Contact with pyrethroid residues (120 ppm) reduced eggs per mite-day for 72 h, then oviposition rates returned to normal. Most eggs (99%) on the control leaflets were oviposited directly on the leaf surface, while 83% and 78% of the eggs in the fenvalerate and permethrin treatments were suspended off the leaf surface onto trichomes, cage walls or in the silk webbing. Oviposition rate on untreated soybean foliage following five days on pyrethroid residues was essentially the same for all TSSM; however, the mites previously exposed to fenvalerate or permethrin residue still oviposited 85% and 37% of their eggs off the untreated leaf surface, respectively. A 120 ppm concentration of fenvalerate directly applied to TSSM resulted in 83% and 100% mortality after 24 h and 48 h and no oviposition. A similar direct exposure to permethrin (120 ppm) resulted in 54% mortality after 48 h, and a 58.5% reduction in eggs per mite-day. Direct exposure to a lower dosage rate (12 ppm) caused little mortality but significantly reduced the number of eggs produced in both fenvalerate and permethrin treatments for 48 h. Oviposition returned to normal after 72 h.

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Effects of Different Neem Formulations on the Twospotted Spider Mite, Tetranychus urticae Koch, on Tomato (Lycopersicon esculentum Mill.)

International Journal of Tropical Insect Science ◽

10.1017/s1742758400012182 ◽

2003 ◽

Vol 23 (01) ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Markus Knapp ◽

Sophia Shaban Kashenge

Keyword(s):

Lycopersicon Esculentum ◽

Tetranychus Urticae ◽

Spider Mite ◽

Twospotted Spider Mite ◽

Lycopersicon Esculentum Mill ◽

Tetranychus Urticae Koch ◽

Twospotted Spider

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AN ECONOMIC THRESHOLD FUNCTION FOR THE TWOSPOTTED SPIDER MITE, TETRANYCHUS URTICAE (ACARI: TETRANYCHIDAE), ON STRAWBERRIES

The Canadian Entomologist ◽

10.4039/ent1189-1 ◽

1986 ◽

Vol 118 (1) ◽

pp. 9-16 ◽

Cited By ~ 14

Author(s):

D.A. Raworth

Keyword(s):

Tetranychus Urticae ◽

Spider Mite ◽

Control Measure ◽

Market Price ◽

Fruit Size ◽

Growth And Yield ◽

Threshold Function ◽

Twospotted Spider Mite ◽

Economic Threshold ◽

Twospotted Spider

AbstractThe growth and yield responses of “Totem” strawberries, Fragaria × ananassa, to 4 introduction densities of the twospotted spider mite, Tetranychus urticae Koch, were observed under field conditions in the lower Fraser Valley. At the high-density treatments T. urticae populations peaked at 65 mites/leaflet and declined during harvest. At the medium- and low-density treatments and in the controls, T. urticae had lower and later peaks. Two species of insect predators and 1 phytoseiid species preyed upon T. urticae. Berry weight and number were predicted (R = 0.97, 12 df) from the number of flowering stalks and accumulated mite-days. Yields increased with increasing numbers of flowering stalks and declined with increasing accumulated mite-days. A $1300 yield loss/ha was observed when 2500 mite-days accumulated between 15 May and 16 July. Fruit size was not affected by T. urticae. Yield equations were developed so that a mite sample 1–5 weeks before harvest can be used to predict dollars lost due to T. urticae. The data allow the grower to determine an economic threshold based on the number of weeks before harvest, mite sample precision, differences in environmental conditions relative to the present study, the control measure to be used, and the market price to the grower.

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