Mint-Garden symphylan

Scutigerella immaculata

Pest description and crop damage Small (less than 0.25 inch), white, centipede-like animals that feed on hairs and meristematic tissue of roots and underground stems. Heavy feeding causes plant stunting, poor stem elongation, and small, chlorotic leaves. This arthropod is a severe pest of many crops in western Oregon.

Biology and life history Populations build rapidly in spring and summer, and usually migrate downward from late summer through fall as soil temperatures rise and moisture content drops. Populations migrate up toward soil surface in the fall as soil moisture increases with the onset of rain. They may damage roots during mild winters.

Scouting and thresholds Take soil samples roughly a standard shovel width (roughly 1 cubic ft) to a depth of 8 to 12 inches. Symphylans usually are sampled in April, May, and June shortly after irrigation or rain when soil is moist. Soil should be nearly at carrying capacity, but sufficiently dry so it fractures or crumbles easily, exposing symphylans in natural tunnels, crevices, worm holes, etc. Damage to mint likely occurs at densities of five to ten per cubic ft of soil.

Management-chemical control

Pre-plant

  • chlorpyrifos (Lorsban Advanced) at 1.88 lb ai/a. PHI 90 days. Broadcast and incorporate at planting. Do not use in conjunction with a foliar application of chlorpyrifos.
  • 1,3-dichloropropene (Telone II) at 18 to 35 gal/a only as a broadcast treatment. See labels for use rate and application methods.
  • ethoprop (Mocap EC or 15G) at 3 lb ai/a (6 lb ai/a if nematodes also a problem). PHI 225 days. REI 48 to 72 hr. Prior to planting evenly broadcast 15G or EC over soil surface and immediately incorporate to a depth of 2 to 4 inches using rotary tiller or hoe, harrow, double disk or with 1 to 2 inches of irrigation water followed by another 1 to 2 inches when the soil becomes moist but not dry. Make only one application whether pre-plant or post-harvest per growing season.
  • metam sodium-See Vapam label for use rate, timing and application methods.

Post-harvest

  • ethoprop (Mocap EC or 15G) at 3 lb ai/a (6 lb ai/a if nematodes also a problem). PHI 225 days. REI 48 to 72 hr. Use as pre-plant or after last harvest. evenly broadcast 15G or EC over soil surface and immediately incorporate to a depth of 2 to 4 inches using rotary tiller or hoe, harrow, double disk or with 1 to 2 inches of irrigation water followed by another 1 to 2 inches when the soil becomes moist but not dry. Make only one application whether pre-plant or post-harvest per growing season.

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