Welcome to
Caterpillars Count!

Caterpillars Count!

General Tips

  • If you want to submit your observations through the iTunes or Android app, you should bring your phone with you to the site location.
  • Once you're at the site location, the leaves you survey should be no more than 6 ft. off of the ground, although the plant you survey may be much taller.
  • If you realize that the plant you are surveying has a dwindling leaf-supply, you can also survey plants of the same plant species in the general vicinity.

Full Breakdown

A typical survey with the iTunes or Android app should be completed as follows:

Site Information

  1. SURVEY LOCATION CODE. Enter the short code listed on the colored branch tag. The site name, Survey Circle and Survey location should pop up automatically in the color corresponding to the branch tag color.
  2. OBSERVATION METHOD. Tap Visual Survey or a Beat Sheet Survey depending on the observation method your site manager has specified.
  3. NOTES. Enter notes about potentially relevant observations that might apply to the entire survey as a whole. For example, perhaps the branch was bent or disturbed since the last time it was surveyed.
  4. WET LEAVES. Check the box if it has recently rained and all of the leaves on the survey tree are very wet.
  5. Tap CONTINUE to enter in arthropod observations.

Arthropod Information

  1. DID YOU FIND ANY ARTHROPODS? Click yes or no as appropriate.
  2. If NO, continue on to #16 below. If YES, continue to #8 below.
  3. ARTHROPOD GROUP. Select the Order or group to which the arthropod(s) you observed belongs in the Arthropod Group dropdown menu. Note, you will enter a separate record for each different combination of arthropod group and size you encounter. For example, if you conducted a survey and saw 5 ants, four of which were 3 mm and one of which was 10 mm, you would fill out two separate observation records: 1 for the ants of size 3 mm, and 1 for the ant of size 10 mm.
    1. If the appropriate arthropod Order is not listed in the dropdown menu, but you know what it is, you may select "OTHER" and describe it in the NOTES field.
    2. If you are not sure what type of arthropod you observed, or if you are deciding between two orders, you may select "UNIDENTIFIED" and then describe any relevant aspects of its appearance in the NOTES. Make sure to include key features, so that it may be identified later.
  4. LENGTH: Estimate the body length of the arthropod to the nearest millimeter, not counting antennae or legs that extend out in front or behind. Therefore, a daddy longlegs is going to be ~7mm, not ~40mm because we are not including the length of the legs. We only care about arthropods that are at least 2 mm long. Don't spend time sweating the small stuff! Note that the diameter of your classic Bic ballpoint pen or wooden pencil is ~8 mm. The diameter of a standard Sharpie marker is ~11 mm.
  5. QUANTITY: Record the quantity of arthropods observed of this group and size.
  6. PHOTO: You may take an optional photo of the arthropod. This can be helpful especially if it is an unidentified arthropod. Taking photos of the arthropods you find within the app is optional, but we strongly encourage photos of caterpillars! Arthropod photos from your surveys will automatically get shared with the Caterpillars Count! iNaturalist page, and you will be able to see experts weigh in on what you've seen!
  7. NOTES: Record any relevant aspects of the arthropod(s) you observed, particularly if you have categorized it as "OTHER" or "UNIDENTIFIED."
  8. Click "SAVE" to add this observation record to your survey. You will see a hyperlinked summary of the observation you just entered. If it is incorrect, click on the record name to edit. You can also delete the record if necessary.
  9. To add a new observation record for this site location, click ADD ANOTHER GROUP at the bottom of the Arthropod Information Summary.
  10. Once you have entered all observations for this survey location, click CONTINUE.

Plant Information

  1. PLANT SPECIES. This field will automatically fill in when you type in the Survey Location Code.
  2. NUMBER OF LEAVES. If you conduct a Visual Survey, this count will be 50 and cannot be edited. If you conduct a Beat Sheet Survey, please estimate the number of leaves that were hanging directly over the beat sheet when you beat the branch. For our purposes, each individual leaflet within a compound leaf will be counted as one leaf (e.g. hickory, buckeye, ash, etc.).
  3. AVERAGE LEAF LENGTH. Estimate the length of a typical leaf from the branch you are surveying.
  4. HERBIVORY SCORE. Give your 50-leaf sample an herbivory score based on how much leaf damage is present. If you summed all of the observed leaf holes together over a 50-leaf survey and were able to cover 5 average leaves, that would be 10%. If leaf holes only sum to about 2 average leaves worth, that would be 4%, etc. Herbivory scores are as follows: None, Trace (<5%), Light (5-10%), Moderate (10-25%), Heavy (>25%).


  1. Tap FINISH and move on to the next survey location once you've recorded all arthropods observed and the plant information for the tree you surveyed.