Skip to content

Core ASUHIC conventions for geo-referencing

An updated summary of conventions used in our insect collection to ensure consistent and accurate geo-referencing. [Prequel: Go to SCAN and log in; then proceed to “My Profile”, then “Specimen Management”, then select ASUHIC.] Blog post in development!

We have four basic cases to work through, ordered from really good to really poor information available on the actual specimen label. Execute the subsequent steps like a hierarchical decision tree. Meaning: Check whether you have Case 1; if so, then resolve accordingly. If not, then check next whether you have Case 2; if so, then resolve accordingly. And so on, until reaching Case 4. Using Case 2 whenever possible will minimize introductions of slightly varying latitude/longitude information that is not reflected in the actual label information. Therefore we obtain more consistent, and more readily searchable occurrence records and geo-references.

Case 1: Specimen label already contains latitude/longitude information. [Source: Label]

  • Sub-Case 1-A: Specimen label has decimal latitude/longitude information.
    • Example: 32.76250 -109.79722.
    • Action: Enter lat/long information into SCAN as is.
  • Sub-Case 1-B: Specimen label has degree / minute (/ second) information.
    • Examples: 32°76’52”; or 32°76’52.24”; or 32°76.522′ (caution – these three are not identical!).
    • Action: Convert directly in SCAN interface (“Tools”; see screenshot inserted above) to decimal rendering; then “use as is”.

Case 2: specimen has a locality that has already been georeferenced in SCAN. [Source: SCAN]

  • Example: locality (approximately) reads “1 mi. S of Portal” or “Mesa”.
  • Action: Search SCAN collection [Locality] for “of Portal” (or even the full string above to minimize returned records); and identify the OLDEST record [= lowest ASUHIC number] that has exactly “1 mi. S of Portal”. Use exactly these lat/long values; in this example “31.90321, -109.15613” (see inserted images).
  • URL:[]=&db[]=1&x=21&y=12

Case 3: specimen has a locality that is so simple and unambiguous that GEOLocate returns a single value (green spot).

=> Example: “Green Valley, AZ”.
=> Action: use exactly these (standardized GEOLocate) coordinates.

Case 4: specimen has no lat/long information, the locality is not in SCAN, and GEOLocate does not produce an obvious match.

=> Example: “12.5 km SW of Dateland, AZ”.
=> Action: use a combination of SEINet and Google Earth to understand exactly what the likely collecting locality could be. Keep in mind that entomologists tend to drive along roads and use the mileage along a road as a proxy for distance (as opposed to distance in the air along a straight line). A lot of collecting is done along some sort of road or path. Google Earth can help measure distance; SEINet often has popular collecting sites marked as such (many occurrence records).
=> Action: The “Add Path” (three-point line) and “Add Placemark” (yellow tack) functions in Google Earth will allow measuring distances and selecting a lat/long pair that can be entered into SCAN. URL for SEINet:

In summary; the five possible georeferencing sources are: (1) Label, (2) SCAN, (3) GEOlocate, (4) SEINet, and (5) Google Earth.

McMillan Campground is a good SEINet example.

No comments yet

Leave a Reply

You may use basic HTML in your comments. Your email address will not be published.

Subscribe to this comment feed via RSS