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SDSU Plant Diagnostic Clinic

Collection and Submission Instructions

Please follow the instructions for collecting and submitting samples for diagnostic testing:

Plants  Shrubs  Trees  Turf  Insect ID

Plants

  1. Provide Information
    1. Download our form (be sure to fill it out completely).
  2. Map it Out
    1. Record location of the infected plant
      NOTE: Be sure to look at the infected plant proximity to healthier plants
    2. Look around the environment
      Examples include: irrigation, shading, proximity to sidewalks, parking lots, buildings, and past damage such as construction. NOTE:This will help you determine if the disease is spreading and it will help form a mental picture of what the site was like to the diagnostician.
  3. Dig up the Plant
    1. Include BOTH roots and soil
      BE AWARE:Symptoms you see on the leaves and stems of the plant may be the result of root infections or poor soil conditions; therefore, make sure to include as much of the plant material as possible. Photos are helpful if taking an entire plant sample isn’t possible.
  4. Package the Sample
    1. Keep each part of the plant separated
      Root and Soil: Wrap the roots and soil in a plastic bag, tie/seal bag around the stem just above the soil (loosely tie the plastic so air exchange occurs)
      Plant: Place entire plant into a Ziploc bag along with the wrapped roots and soil. Place a dry paper towel inside the Ziploc bag to prevent the plant from rotting. 
    2. Placement and Shipment
      Place the Ziploc bag into a box and fill the empty spaces with newspaper. This will keep the sample from becoming damaged during shipment.
  5. Ship it Quick
    1. Diseases spread rapidly so you may need to ship your samples by two-day or preferably by overnight delivery.

Shrubs

  1. Digging Shrubs When Possible 
    1. Use Shovel or Spade 
      Dig around the root ball and DO NOT pull the plant up because you will tear weakened roots!
    2. Cut the root ball in half 
      The entire roots are not needed but retain the side of the root ball that displays symptoms. Remove any excess soil. Also, make sure to retain the small, fibrous roots.
    3. Remove Branches 
      Remove a couple of branches about halfway down the plant.
    4. Trim Shrub 
      Trim the remaining large branches back, but keep some with the sample.
  2. Wrapping Shrubs
    1. Use a large garbage bag to contain the roots and soil.
    2. Place another bag over the leaves and branches for shipping.
  3. Take Additional samples 
    1. Make sure to take a sample of roots and soil from any adjacent plant that is showing symptoms.
  4. Label each bag
    1. Be sure to include (DATE, NAME, and specify SAMPLE)
  5. Provide Information
    1. Download our form (be sure to fill it out completely).

Trees

  1. Sampling Trees
    1. Look for signs and symptoms that can be sampled
    2. Branches
      Sample the branches by cutting them several inches beyond each side of the affected area.
      Be sure to INCLUDE live wood in the sample and also collect some fine roots and soil if possible.
    3. Note: Take note of any change in the environment or property around the tree, such as, digging weed spraying, new side walk, etc.

Turf

  1. Provide Information 
    1. Download our form (be sure to fill it out completely).
  2. Digging Turf
    1. Dig a 6x4 inch deep “plug” from the leading edge of the dying turf patches (make sure the root system is intact).
    2. Include BOTH affected and non-affected grass.
  3. Wrapping Turf
    1. Wrap each plug in wax paper or several layers of newspaper to help hold soil intact.
  4. Placement and Shipment
    1. Place “plug” into plastic bag and then into a box for shipping
      Make sure the plugs are packed tightly with crumpled newspaper to prevent shifting and loosening of soil during shipment.

Insect Identification

Submitted insect samples must be:

  1. Dead. We recommend freezing the sample for at least 24 hours prior to mailing. If you are sending infested plant material, please follow the directions for submitting plant samples.
  2. In good condition. Smashed insects (e.g., flyswatter victims) are difficult to identify.
  3. Shipped in a hard-sided container. Insects taped to index cards or mailed in envelopes arrive in pieces and cannot be identified. Never send samples in cotton. Sample parts will get tangled in the cotton and easily break.
  4. Accompanied by the sample submission form. Please indicate where and when the specimen was found and what (if any) problems or concerns you have about the specimen.

STICKY TRAPS: Sticky traps and tapes are accepted in limited quantities. The number of arthropods trapped can be overwhelming and specimens on tape tend to be in poor condition. Your pest control operator may be able to identify a majority of the trapped specimens.

MEDICAL SAMPLES: Samples collected from humans will only be accepted if they are submitted from a medical office. If you believe that insects or other arthropods are infesting your body, you must consult with a medical professional and have that professional submit a sample to the clinic.

IMAGES (email): Digital images may be used for identification and should be accompanied by the sample submission form. Pictures of live specimens are preferred. Slow down active specimens by placing them in a freezer or refrigerator for a short time before taking pictures. In general, specimens that are less than 5 mm (1/4 inch) are too small to be identified from images using common digital equipment. If you cannot get a clear image of a small specimen, please send the specimen to the clinic.

Submit your three best images. One of these images should be with a ruler or coin for scale. Include an image of the top of the specimen. Clear shots of the side, bottom and wing pattern are also helpful. If an identification cannot be made from the images, the diagnostician will request that you send in the specimen (follow the guidelines above).