Our insect of the week for June 2, 2025 is the clubbed mydas fly – Mydas clavatus (Drury, 1773) [DIPTERA: Mydidae]. It is native to central Illinois and was one of the first large flies which caught my attention as a young entomologist. Yes, they are large (up to 3 cm in length). Adults have an orange or red mark on their abdomen. Adults are Batesiam mimics of spider wasps and are quite bold in their movements. After all, once you have ben stung by a spider wasp, you will given them significant respect. Yes, personal experience, but that is a story for another day.

Eggs are laid in rotting wood and larvae are predators of grubs of the scarab beetles Osmoderma. These can be found in standing or downed trees with extensive central rot. Adults have been observed feeding on pollen and nectar. You will often see the adults in open woodlands and even suburban yards (my first encounter was within a block of the square in Washington).

The specimen in the photographs was collected by our former member, Gordon Adams, in July, 1969 (Peoria Co.,. IL). This photograph results from stacking nearly 280 individual photos together. The top photo shows the adult fly in dorsal view. The bottom photo shows the same specimen in lateral view.

The photograph below represents over 400 photos stacked together.