The Mass Moths Database
The data in the Mass Moths database has been taken from several sources, including public and private collections, notebooks, literature and online databases. By far the largest source has been from the professional moth survey work performed by Mark Mello for the Lloyd Center for the Environment, South Dartmouth, MA. The more important online databases include idigbio.com, scan-bugs.org, butterfliesandmoths.org, bugguide.net and inaturalist.org. The data are currently held in an Excel spreadsheet with 37 columns. These columns can be viewed in the ‘Comprehensive data sheet’ of the downloadable Data Collection Template Excel file. All data are critically assessed, as far as possible, by the Mass Moths Team before acceptance in the database. Several records are flagged as being ‘unconfirmed’ (mainly from literature) or ‘uncertain’. The oldest record dates from 1828, from the original description by T.W. Harris of the Squash Vine Borer.
The Lloyd Center for the Environment, South Dartmouth
The Lloyd Center for the Environment is a private not-for-profit institution in Dartmouth, MA situated on 82 acres between the Slocum and Little Rivers with trails and a visitor center. Its mission is to protect nature through research, education and outreach in southern New England. Mark Mello has conducted Lepidoptera surveys in Massachusetts, Rhode Island and New Hampshire over 40+ years. The bulk of the 60,000+ moth collection amassed during this time is in the process of being transferred to the Harvard Museum of Comparative Zoology ensuring permanent preservation. One major initiative has been the Nantucket Moth Survey. For more information on this survey please see the links section on the right.
Mapping
Distribution maps are prepared using the mapping software DMAP. The base map used is the ‘Elevation and Shaded Relief Map from 2005’ overlaid with ‘Massachusetts Towns’, both layers downloaded from OLIVER, MassGIS (Bureau of Geographic Information), Commonwealth of Massachusetts EOTSS. Locality data are allocated to grid squares. Each grid square is approximately 5 x 5 miles (more precisely 5.00 miles latitude x 5.02 +/- 0.067 miles longitude). There are 423 full or partial grid squares covering Massachusetts (land only). To allow data analysis in Excel, each row and column of the grid is numbered from 10 upwards and each grid square is numbered using the combination of the column and row numbers.

Many records, especially older ones, give only the town as locality. For these data, the central point of each town is used to plot the data. Records giving just the county, are not plotted, but they are used for the County List. Also not plotted are iNaturalist records with obscured localities or which are otherwise too imprecise. In the database itself, the locality accuracy of each record is allocated to different categories: State, County, Town, ‘Close estimate’ (more accurate than town, but coordinates not originally stated), ‘Very close or exact’ (coordinates given by observer).