The following is information on managing cool season mites in the landscape. These pests are now active in Delaware.
Cool Season Mites.
This year has been unusually cool, so cool season mites may become active sooner than previous years. Cool season mites such as spruce spider mites and southern red mites become more active as temperature are consistently in the 60's and 70's. Shake a branch or small portion of the plant against a clipboard with a white sheet of paper to monitor mite populations. Mites will begin to move a few moments after shaking and will appear as dots the size of periods. Predatory mites usually move quicker than herbivorous mites and a hand lens will be helpful to recognize the pests. Predatory mites and small lady beetles are common predators of pest mites. Miticides available for controlling these mites include: hexythiazox (Hexygon, Savy), bifenazate (Floramite), abamectin (Avid) and others. Research has shown bifenthrin (Talstar) to cause mite resurgences because it also kills many of the beneficial arthropods helping to keep populations low.
Information from Brian Kunkel, Ornamental IPM Specialist, UD
Showing posts with label cool season mites. Show all posts
Showing posts with label cool season mites. Show all posts
Friday, September 4, 2009
Tuesday, September 23, 2008
Landscape and Nursery - Cool Season Mites
The following is information on cool season mites in the landscape. These mites will be more active now with the reduced temperatures.
COOL SEASON MITES.
As temperatures consistently return to the 60's and 70's during the next few weeks, spruce spider mite and southern red mite activity will increase. Spruce spider mites feed on fir, arborvitae, spruce, Douglas-fir, and other conifers, feeding on older foliage first. Spruce spider mites are olivedark red with reddish-yellow legs and two reddish eye spots with a pale stripe down the back (visible with a microscope). Spruce spider mites start feeding in the fall around 2301 3957 [3094 peak] GDD and continues until there is a hard frost. In the summer, damage appears as bleaching, yellowing, stippling or bronzing of the needles. Damage visible on trees in summer is from intensive fall feeding.
Southern red mites feed on a wide variety of plants including azaleas, camellias, hollies, clethra, juniper, elaeagnus, hibiscus, photinia and rose. Nymphs and adults are active starting around 2401 3584 [3034 peak] GDD and 1913 3518 [2933 peak] GDD respectively. This mite has a dark reddish to brown abdomen with a pinkish to red cephalothorax and a pale mid-stripe. It feeds on the lower leaf surface but during high populations may be found on upper surfaces. Damaged leaves may be brown to gray and drop prematurely.
Monitor with a clipboard and a white sheet of paper, looking for dots the size of periods. Watch for predatory mites and small lady beetles; both are predators of the spruce spider mite and should be conserved. Miticides available for control include hexythiazox (Hexygon, Savy), bifenazate (Floramite), abamectin (Avid) and others. Research has shown bifenthrin (Talstar) can cause mite 'resurgences' because natural enemies are killed; thus mite eggs are able to hatch without threat of predators.
Information from Dr. Brian Kunkel, Ornamental IPM Specialist, UD
COOL SEASON MITES.
As temperatures consistently return to the 60's and 70's during the next few weeks, spruce spider mite and southern red mite activity will increase. Spruce spider mites feed on fir, arborvitae, spruce, Douglas-fir, and other conifers, feeding on older foliage first. Spruce spider mites are olivedark red with reddish-yellow legs and two reddish eye spots with a pale stripe down the back (visible with a microscope). Spruce spider mites start feeding in the fall around 2301 3957 [3094 peak] GDD and continues until there is a hard frost. In the summer, damage appears as bleaching, yellowing, stippling or bronzing of the needles. Damage visible on trees in summer is from intensive fall feeding.
Southern red mites feed on a wide variety of plants including azaleas, camellias, hollies, clethra, juniper, elaeagnus, hibiscus, photinia and rose. Nymphs and adults are active starting around 2401 3584 [3034 peak] GDD and 1913 3518 [2933 peak] GDD respectively. This mite has a dark reddish to brown abdomen with a pinkish to red cephalothorax and a pale mid-stripe. It feeds on the lower leaf surface but during high populations may be found on upper surfaces. Damaged leaves may be brown to gray and drop prematurely.
Monitor with a clipboard and a white sheet of paper, looking for dots the size of periods. Watch for predatory mites and small lady beetles; both are predators of the spruce spider mite and should be conserved. Miticides available for control include hexythiazox (Hexygon, Savy), bifenazate (Floramite), abamectin (Avid) and others. Research has shown bifenthrin (Talstar) can cause mite 'resurgences' because natural enemies are killed; thus mite eggs are able to hatch without threat of predators.
Information from Dr. Brian Kunkel, Ornamental IPM Specialist, UD
Wednesday, October 24, 2007
Landscape - Cool Season Mites
Cool season mites are a common pest of evergreen species. The following is an article on the subject.
Cool Season Mites: Plan a dormant oil application on plants affected by these pests this fall. Oil sprays will kill the presently active adults as well as some of the overwintering eggs. Be sure to monitor for mites next season, since where it was a problem in the past it will most likely be a problem again, and the dormant oil application will probably not give 100% control.
Remember: Adult spruce mites (which attack conifers) will remain active into December and the overwintering eggs will typically hatch in April of next year. The two-spotted mites are warm season mites that overwinter as adults under the plant and will not become active again until the weather warms in late May. Dormant oil applications are not effective against the two-spotted mites.
Article by Steven K. Rettke, Ornamental IPM Program Associate, Rutgers Cooperative Extension (NJ), in the November 2, 2006 edition of the Landscape, Nursery, and Turf Edition of the Plant and Pest Advisory.
Cool Season Mites: Plan a dormant oil application on plants affected by these pests this fall. Oil sprays will kill the presently active adults as well as some of the overwintering eggs. Be sure to monitor for mites next season, since where it was a problem in the past it will most likely be a problem again, and the dormant oil application will probably not give 100% control.
Remember: Adult spruce mites (which attack conifers) will remain active into December and the overwintering eggs will typically hatch in April of next year. The two-spotted mites are warm season mites that overwinter as adults under the plant and will not become active again until the weather warms in late May. Dormant oil applications are not effective against the two-spotted mites.
Article by Steven K. Rettke, Ornamental IPM Program Associate, Rutgers Cooperative Extension (NJ), in the November 2, 2006 edition of the Landscape, Nursery, and Turf Edition of the Plant and Pest Advisory.
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