Are pollinating hawk moths declining in the Northeastern United States?

While obviously not specific to Ontario, this recent (Oct 2017) study examines a group of Sphingids that largely overlap with the Ontario species list, and that are subject to some of the same influences in terms of environmental changes and the presence of the introduced tachnid fly (Compsilura concinnata).

The four diurnal moths in the study showed no decline - and three of the four are commonly reported in Ontario according to TEA records. The fourth species, hemaris gracilis, is uncommon in Ontario and is ranked S3 by the Natural History Information Centre.

Several other species experienced declines over the century-long time period, especially those whose larvae were active in the summer, and that feed on trees or vines. Those species seem to be more susceptible to the tachnid fly.

The full report is available for download here:
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0185683

Posted on February 15, 2018 12:43 AM by dkaposi