Table 1. Sampling effort in past and present field studies.
| Year | first day | last day | No fields | No localities | No recordsa |
| 1930 | 30 June | 03 Aug. | 3 | 3 | 4 |
| 1931 | 11 July | 10 Sep. | 4 | 3 | 9 |
| 1932 | 11 July | 12 Aug. | 7 | 7 | 14 |
| 1933 | 18 July | 26 July | 6 | 4 | 31 |
| 1934 | 17 June | 11 July | 5 | 2 | 12 |
| 2008 | 20 June | 06 Aug. | 12 | 12 | 42 |
| 2009 | 03 June | 20 Aug. | 17 | 16 | 99 |
| Total past | 25 | 10 | 70 | ||
| Total present | 29 | 19 | 141 | ||
a
For present observations, number of records represents aggregated data (observations aggregated within each observation day for each field).