I thought I would focus on something a bit different for our insect of the week for May 25, 2026. We see a tremendous diversity of insects all around us each day (when we are paying attention). It is easy to forget that most of the species we see are a small remnant of the vast insect lineage through time. In Illinois, we were fortunate to have had a significant amount of Paleozoic fossils exposed in the mid-1900s. This was due to extensive strip mining of coal in central and northern Illinois. I thought I would showcase some Illinois insects this week (and next) which lived in tropical climes (the Carboniferous coal swamps of what we now call Illinois) and are preserved in concretions from the Francis Creek Shale. This week I showcase a specimen from my collection. As best I can tell, this has been correctly identified by a paleo-entomologist before I obtained the specimen. However, it is somewhat difficult to be certain due to the limited remains. Personally, I can only hope I look this good after over 300 million years. Without further introduction, I present to you…

Gerarus danielsi described by Anton Handlirsch (an Austrian entomologist) in 1906. [Clade: Panorthoptera, Order: Hypoperlida, Family: Geraridae]. This group is quite problematic and is currently thought to belong to insects which gave rise to hemipteroids (thrips, lice, and bugs). Many of the insect orders known from Pennsylvanian and Permian times became extinct at the close of the Permian (along with major marine invertebrates such as trilobites). Roughly 95% of all life went extinct during the “great dying” at the Permian/ Triassic boundary. This specimen is from Pit 11 (near Braidwood, Illinois).

If you would like to learn a bit more about this extinct group of insects, I recommend starting with this 2008 reference work. A number of illustrations are included. What fascinates me the most about fossils from this time is that these insects were in the process of evolving flight. Gerarids were rather unusual insects (by our standards today). I thought readers might enjoy a bit of a diversion into the rich Illinois past. Fun fact – there are almost no Mesozoic strata exposed in Illinois (except for a small bit near Macomb). The Pleistocene glaciers did a fine job of obliterating that part of our history. One part of the concretion is shown below. The other side is shown in the lower photo. I hope you enjoy this bit of diversion into the ancient past of Illinois insects.