Our insect of the week for October 13, 2025 is another mantidfly – Say’s mantidfly, Dicromantispa sayi [NEUROPTERA: Mantispidae], described by the American entomologist Nathan Banks in 1897. As we saw in another Illinois mantidfly last week, the raptorial forelegs are similar to what we see in mantids. Convergent evolution again as these insects are also predators.

This species is native to central Illinois, and ranges from North America to islands in the Caribbean Sea and Central America.

Behavior of larva are similar to what we learned about last week. Adults are often found along forest edges with prairies where spiders are often present. In addition to wolf spiders, select crab spiders are also sought out so the larvae can consume their eggs.

The specimen in this photograph was collected by Mark DuBois in Peoria County, Illinois in 2019. The photo is the result of stacking the focused part of over 300 separate images.