by Carl Strang
Today’s seasonal comparison is between first appearance dates of insects at Mayslake Forest Preserve, through May. This includes April data, as there were not enough species in that month to consider alone. As was the case with plants, the most dramatic difference was between this year and last: 15 species appeared a median 33 days later in 2013 than in 2012.
The differences from other years were smaller: 10 days later in 2013 than 2011 (15 species), likewise 10 days later than 2010 (13 species), and 5 days later than 2009 (12 species).
The numbers did not fully parallel those for flowering dates, in part because the months were combined, and in part because the sample sizes were smaller. Nevertheless, the 2013-2012 comparison is the consistent one. Also, this year is confirmed as the latest of the five I have been at Mayslake.