The Evolution of True Bugs

The Order Hemiptera - True Bugs - contain a major proportion of insect diversity - over 120,000 described species including shieldbugs, plant bugs, bed bugs, pondskaters, cicadas, water bugs, aphids and scale insects. A recent scientific paper takes a shot at a DNA taxonomy for this diverse group. The researchers examined the DNA sequences of 2,395 genes from 193 groups. Unless you're into DNA taxonomy, the details of the paper are hard going, but the conclusions are fascinating. In summary:

• The bugs split from the Paleoptera (dragonflies, damselflies, and mayflies) and Neoptera (all other insects) 437 million years ago, before the Carboniferous period. This great age helps to explain the diversity and species richness of this group.
• Thrips (Thysanoptera) are the closest living relatives of true bugs and allies (Hemiptera).
• The results agree with evidence from the fossil record that the earliest hemipteroids fed on detritus, pollen, fungi, or spores (as do most modern bark lice and thrips). Plant-fluid feeding probably coincided with the origin of Hemiptera and evolved independently in thrips.

Phylogenomics and the evolution of hemipteroid insects PNAS USA, 21 Nov 2018) https://doi.org/10.1073/pnas.1815820115